WO2010071641A1 - Additif pour carburant contenant des nanoparticules de dioxyde de cérium modifié en treillage - Google Patents

Additif pour carburant contenant des nanoparticules de dioxyde de cérium modifié en treillage Download PDF

Info

Publication number
WO2010071641A1
WO2010071641A1 PCT/US2008/087133 US2008087133W WO2010071641A1 WO 2010071641 A1 WO2010071641 A1 WO 2010071641A1 US 2008087133 W US2008087133 W US 2008087133W WO 2010071641 A1 WO2010071641 A1 WO 2010071641A1
Authority
WO
WIPO (PCT)
Prior art keywords
process according
cerium dioxide
nanoparticles
transition metal
cerium
Prior art date
Application number
PCT/US2008/087133
Other languages
English (en)
Inventor
Albert Gary Difrancesco
Thomas D. Allston
Richard K. Hailstone
Andreas Langner
Kenneth J. Reed
Original Assignee
Cerion Technology, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to CN2008801326631A priority Critical patent/CN102281945A/zh
Priority to RU2011129305/04A priority patent/RU2487753C2/ru
Application filed by Cerion Technology, Inc. filed Critical Cerion Technology, Inc.
Priority to EP08879024.1A priority patent/EP2379221A4/fr
Priority to BRPI0823310-1A priority patent/BRPI0823310B1/pt
Priority to MX2011006461A priority patent/MX2011006461A/es
Priority to PCT/US2008/087133 priority patent/WO2010071641A1/fr
Priority to KR1020117016496A priority patent/KR101605465B1/ko
Priority to US13/140,648 priority patent/US10435639B2/en
Priority to JP2011542092A priority patent/JP5438772B2/ja
Priority to CA2747547A priority patent/CA2747547C/fr
Priority to AU2008365234A priority patent/AU2008365234B2/en
Priority to US12/549,776 priority patent/US8679344B2/en
Priority to US12/779,602 priority patent/US8883865B2/en
Publication of WO2010071641A1 publication Critical patent/WO2010071641A1/fr
Priority to US14/537,161 priority patent/US9340738B2/en
Priority to US14/537,993 priority patent/US9303223B2/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F17/00—Compounds of rare earth metals
    • C01F17/20—Compounds containing only rare earth metals as the metal element
    • C01F17/206—Compounds containing only rare earth metals as the metal element oxide or hydroxide being the only anion
    • C01F17/224—Oxides or hydroxides of lanthanides
    • C01F17/235—Cerium oxides or hydroxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/20—Catalysts, in general, characterised by their form or physical properties characterised by their non-solid state
    • B01J35/23—Catalysts, in general, characterised by their form or physical properties characterised by their non-solid state in a colloidal state
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/002—Mixed oxides other than spinels, e.g. perovskite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/10—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of rare earths
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/20—Vanadium, niobium or tantalum
    • B01J23/22—Vanadium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/24—Chromium, molybdenum or tungsten
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/32—Manganese, technetium or rhenium
    • B01J23/34—Manganese
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/72—Copper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/745—Iron
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F17/00—Compounds of rare earth metals
    • C01F17/10—Preparation or treatment, e.g. separation or purification
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
    • C01F17/00—Compounds of rare earth metals
    • C01F17/30—Compounds containing rare earth metals and at least one element other than a rare earth metal, oxygen or hydrogen, e.g. La4S3Br6
    • C01F17/32—Compounds containing rare earth metals and at least one element other than a rare earth metal, oxygen or hydrogen, e.g. La4S3Br6 oxide or hydroxide being the only anion, e.g. NaCeO2 or MgxCayEuO
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G25/00—Compounds of zirconium
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G3/00—Compounds of copper
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/0018—Mixed oxides or hydroxides
    • C01G49/0054—Mixed oxides or hydroxides containing one rare earth metal, yttrium or scandium
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/009—Compounds containing, besides iron, two or more other elements, with the exception of oxygen or hydrogen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/04—Oxygen-containing compounds
    • C08K5/10—Esters; Ether-esters
    • C08K5/101—Esters; Ether-esters of monocarboxylic acids
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L10/00—Use of additives to fuels or fires for particular purposes
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L10/00—Use of additives to fuels or fires for particular purposes
    • C10L10/08—Use of additives to fuels or fires for particular purposes for improving lubricity; for reducing wear
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M125/00—Lubricating compositions characterised by the additive being an inorganic material
    • C10M125/10—Metal oxides, hydroxides, carbonates or bicarbonates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/03—Precipitation; Co-precipitation
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/30—Three-dimensional structures
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/50—Solid solutions
    • C01P2002/52—Solid solutions containing elements as dopants
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/04—Particle morphology depicted by an image obtained by TEM, STEM, STM or AFM
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/51—Particles with a specific particle size distribution
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C10L1/12—Inorganic compounds
    • C10L1/1233—Inorganic compounds oxygen containing compounds, e.g. oxides, hydroxides, acids and salts thereof
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C10L1/12—Inorganic compounds
    • C10L1/1233—Inorganic compounds oxygen containing compounds, e.g. oxides, hydroxides, acids and salts thereof
    • C10L1/125—Inorganic compounds oxygen containing compounds, e.g. oxides, hydroxides, acids and salts thereof water
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C10L1/14—Organic compounds
    • C10L1/16—Hydrocarbons
    • C10L1/1608—Well defined compounds, e.g. hexane, benzene
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C10L1/14—Organic compounds
    • C10L1/16—Hydrocarbons
    • C10L1/1616—Hydrocarbons fractions, e.g. lubricants, solvents, naphta, bitumen, tars, terpentine
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C10L1/14—Organic compounds
    • C10L1/18—Organic compounds containing oxygen
    • C10L1/182—Organic compounds containing oxygen containing hydroxy groups; Salts thereof
    • C10L1/1822—Organic compounds containing oxygen containing hydroxy groups; Salts thereof hydroxy group directly attached to (cyclo)aliphatic carbon atoms
    • C10L1/1824—Organic compounds containing oxygen containing hydroxy groups; Salts thereof hydroxy group directly attached to (cyclo)aliphatic carbon atoms mono-hydroxy
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C10L1/14—Organic compounds
    • C10L1/18—Organic compounds containing oxygen
    • C10L1/185—Ethers; Acetals; Ketals; Aldehydes; Ketones
    • C10L1/1852—Ethers; Acetals; Ketals; Orthoesters
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C10L1/14—Organic compounds
    • C10L1/18—Organic compounds containing oxygen
    • C10L1/188—Carboxylic acids; metal salts thereof
    • C10L1/1881—Carboxylic acids; metal salts thereof carboxylic group attached to an aliphatic carbon atom
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C10L1/14—Organic compounds
    • C10L1/18—Organic compounds containing oxygen
    • C10L1/188—Carboxylic acids; metal salts thereof
    • C10L1/1881—Carboxylic acids; metal salts thereof carboxylic group attached to an aliphatic carbon atom
    • C10L1/1883—Carboxylic acids; metal salts thereof carboxylic group attached to an aliphatic carbon atom polycarboxylic acid
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
    • C10L1/00—Liquid carbonaceous fuels
    • C10L1/10—Liquid carbonaceous fuels containing additives
    • C10L1/14—Organic compounds
    • C10L1/22—Organic compounds containing nitrogen
    • C10L1/222—Organic compounds containing nitrogen containing at least one carbon-to-nitrogen single bond
    • C10L1/2222—(cyclo)aliphatic amines; polyamines (no macromolecular substituent 30C); quaternair ammonium compounds; carbamates
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2010/00—Metal present as such or in compounds
    • C10N2010/06—Groups 3 or 13
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2020/00—Specified physical or chemical properties or characteristics, i.e. function, of component of lubricating compositions
    • C10N2020/01—Physico-chemical properties
    • C10N2020/055—Particles related characteristics
    • C10N2020/06—Particles of special shape or size
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/06—Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00—Specified use or application for which the lubricating composition is intended
    • C10N2040/25—Internal-combustion engines
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00—Specified use or application for which the lubricating composition is intended
    • C10N2040/25—Internal-combustion engines
    • C10N2040/252—Diesel engines

Definitions

  • the present invention relates in general to cerium dioxide nanoparticles and, in particular, to cerium dioxide nanoparticles, Cei -X M x ⁇ 2, containing one or more transition metals (M), and to a method for preparing such particles.
  • These nanoparticles are useful as components of fuel additive compositions, as a wash coat for catalytic converters, or as a catalyst for a reduction/oxidation reaction
  • the trucking industry accounts for more than 5% of the U.S. GDP and is comprised of more that 500,000 for-hire, private and government fleets, including owner operators. It is a barometer of the US economy representing nearly 70% of the tonnage carried by all modes of domestic freight transportation, including manufactured and retail goods.
  • This industry is powered almost exclusively by diesel engines (compressive ignition engines), which are characterized by high torque developed at low rpm and 25% greater thermodynamic efficiency compared to spark ignition (gasoline) engines.
  • diesel-powered vehicles are now required to be fitted with diesel oxidation catalysts (DOC) or some form of catalytic converter and to burn ultra low sulfur diesel fuel, ULSD, ( ⁇ 15 ppm S).
  • DOC diesel oxidation catalysts
  • ULSD ultra low sulfur diesel fuel
  • EGR emissions gas recirculation
  • the ULSD requirement is a consequence of sulfur poisoning of the precious metals on the DOC by high sulfur levels.
  • This legislation has far ranging consequences, as (on road) diesel fuel in the US is consumed at a prodigious rate, 650M gal/week, which is second only to that of gasoline (1300 M gal/wk).
  • Diesel fuel additives in particular, those that include to inorganic metal and metal oxide materials as opposed to organic materials, offer the promise of reduced DPM and improved fuel economy.
  • Kracklaurer U S. Patent No.4,389,220, the disclosure of which is incorporated herein by reference, describes a method of conditioning diesel engines in which a diesel engine is operated on a diesel fuel containing from about 20-30 ppm of dicyclopentadienyl iron for a period of time sufficient to eliminate carbon deposits from the combustion surfaces of the engine and to deposit a layer of iron oxide on the combustion surfaces, which layer is effective to prevent further buildup of carbon deposits. Subsequently, the diesel engine is operated on a maintenance concentration of from about 10-15 ppm of dicyclopentadienyl iron or an equivalent amount of a derivative thereof on a continuous basis.
  • the maintenance concentration is effective to maintain the catalytic iron oxide layer on the combustion surfaces but insufficient to decrease timing delay in the engine.
  • the added dicyclopentadienyl iron may produce iron oxide on the engine cylinder surface (Fe 2 Os), which reacts with carbon deposits (soot) to form Fe and CO 2 , thereby removing the deposits.
  • this method may accelerate the aging of the engine by formation of rust.
  • the catalysts reduce fouling of heat transfer surfaces by unburned carbon while limiting the amount of secondary additive ash, which may itself cause overloading of particulate collector devices or emissions of toxic ultra fine particles when used in forms and quantities typically employed.
  • a fuel containing a fuel-soluble catalyst comprised of platinum and at least one additional metal comprising cerium and/or iron production of pollutants of the type generated by incomplete combustion is reduced.
  • Ultra low levels of nontoxic metal combustion catalysts can be employed for improved heat recovery and lower emissions of regulated pollutants.
  • fuel additives of this type in addition to using the rare and expensive metals such as platinum, can require several months before the engine is "conditioned". By “conditioned” is meant that all the benefits of the additive are not obtained until the engine has been operated with the catalyst for a period of time. Initial conditioning may require 45 days and optimal benefits may not be obtained until 60-90 days. Additionally, free metal may be discharged from the exhaust system into the atmosphere, where it may subsequently react with living organisms.
  • Cerium dioxide is widely used as a catalyst in converters for the elimination of toxic exhaust emission gases and the reduction in particulate emissions in diesel powered vehicles.
  • the cerium dioxide can act as a chemically active component, acting to release oxygen in the presence of reductive gases, as well as to remove oxygen by interaction with oxidizing species.
  • Cerium dioxide may store and release oxygen by the reversible process shown in equation 1.
  • OSC oxygen storage capability
  • ceria acts as an oxygen storage buffer ( much like a pH buffer), releasing oxygen in spatial regions where the oxygen concentration or pressure is low and absorbing oxygen in spatial regions where the oxygen pressure is high.
  • x 0.5
  • ceria is effectively fully reduced to Ce 2 ⁇ 3
  • the maximum theoretical OSC is 1452 micromoles of O 2 per gram of ceria.
  • the redox potential between the Ce 3+ and Ce 4+ ions lies between 1.3 and 1.8V and is highly dependent upon the anionic groups present and the chemical environment (CERIUM: A Guide to its Role in Chemical Technology, 1992 by Molycorp, Inc, Library of Congress Catalog Card Number 92-93444)).
  • Cerium dioxide may provide oxygen for the oxidation of CO or hydrocarbons in an oxygen-starved environment, or conversely may absorb oxygen for reducing the levels of nitrogen oxides (NOx) in an oxygen-rich environment. Similar catalytic activity may also occur when cerium dioxide is added as an additive to fuel, for example, diesel or gasoline. However, for this effect to be useful, the cerium dioxide must be of a particle size small enough, i.e., nanoparticulate (less than 100 nm), to remain suspended by Brownian motion in the fuel and not settle out.
  • cerium dioxide in fuel serves not only to act as a catalyst to reduce toxic exhaust gases produced by fuel combustion, for example, by the "water gas shift reaction"
  • cerium dioxide nanoparticles are particles having a mean diameter of less than 100 nm.
  • the diameter of a nanoparticle refers to its hydrodynamic diameter, which is the diameter determined by dynamic light scattering technique and includes molecular adsorbates and the accompanying solvation shell of the particle.
  • the geometric particle diameter can be estimated using transmission electron micrography (TEM).
  • cerium dioxide nanoparticles can also be added to fuel at an earlier stage to achieve improved fuel efficiency. They can, for example, be incorporated at the refinery, typically along with processing additives such as, for example, cetane improvers or lubricity agents, or added at a fuel distribution tank farm.
  • Cerium dioxide nanoparticles can also be added at a fuel distribution center by rack injection into large (-100,000 gal) volumes of fuel, or at a smaller fuel company depot, which would allow customization according to specified individual requirements.
  • the cerium dioxide may be added at a filling station during delivery of fuel to a vehicle, which would have the potential advantage of improved stabilization of the particle dispersion.
  • Cerium nanoparticles may form a ceramic layer on the engine cylinders and internal moving parts, thereby essentially turning the engine into a catalytic device. Alternatively, they may be recycled in the lubrication oil where they accumulate. Their catalytic efficiency derives from the fact that they provide a source of oxygen atoms during combustion by undergoing reduction according to the equation (1); however, an induction period of several months is usually required before their mpg benefit is observed. This ultimately results in better fuel combustion and reduced levels of particulate material emissions. Additionally, when used as a fuel additive, these nanoparticles may provide improved engine performance by reducing engine friction. As an alternative mode of introduction, cerium dioxide nanoparticles can be added to the lube oil and act as a lubricity enhancing agent to reduce internal friction. This will also improve fuel efficiency.
  • the radicals A which are the same or different, are each an anion of an organic oxyacid AH having a pK a greater than 1, p is an integer ranging from 0 to 5, n is a number ranging from 0 to 2, and m is an integer ranging from 1 to 12.
  • the organic oxyacid is preferably a carboxylic acid, more preferably, a C 2 -C 2 O monocarboxylic acid or a C 4 -Ci 2 dicarboxylic acid.
  • the cerium-containing compounds can be employed as catalysts for the combustion of hydrocarbon fuels.
  • Chopin et al. U.S. Patent No. 6,210,451 discloses a petroleum-based fuel that includes a stable organic sol that comprises particles of cerium dioxide in the form of agglomerates of crystallites (preferred size 3-4 nm), an amphiphilic acid system containing at least one acid whose total number of carbons is at least 10, and an organic diluent medium.
  • the controlled particle size is no greater than 200nm.
  • Birchem et al. U.S. Patent No. 6,136,048, discloses an adjuvant for diesel engine fuels that includes a sol comprising particles of oxygenated compound having a dc > o no greater than 20 nm, an amphiphilic acid system, and a diluent.
  • the oxygenated metal compound particles are prepared from the reaction in solution of a rare earth salt such as a cerium salt with a basic medium, followed by recovery of the formed precipitate by atomization or freeze drying.
  • Lemaire et al. U.S. Patent No. 6,093,223, discloses a process for producing aggregates of eerie oxide crystallites by burning a hydrocarbon fuel in the presence of at least one cerium compound.
  • the soot contains at least 0.1 wt.% of eerie oxide crystallite aggregates, the largest particle size being 50-10,000 angstroms, the crystallite size being 50-250 angstroms, and the soot having an ignition temperature of less than 400 ° C.
  • Hazarika et al. U.S. 7,195,653 B2 discloses a method of improving fuel efficiency and/or reducing fuel emissions of a fuel burning apparatus, the method comprising dispersing at least one particulate lanthanide oxide, particularly cerium dioxide, in the fuel at 1 to 10 ppm , either as a tablet, a capsule a powder or liquid fuel additive wherein the particulate lanthanum oxide is coated with a surfactant selected from the group consisting of alkyl carboxylic anhydrides and esters having an HLB of 7 or less.
  • the preferred coating is dodecyl succinic anhydride.
  • Collier et al. U.S. Patent Appl. Publ. No. 2003/0182848, discloses a diesel fuel composition that improves the performance of diesel fuel particulate traps and contains a combination of 1-25 ppm of metal in the form of a metal salt additive and 100- 500 ppm of an oil-soluble nitrogen-containing ashless detergent additive.
  • the metal may be an alkali metal, an alkaline earth metal, a metal of Group IVB, VIIB, VIIIB, IB, HB, or any of the rare earth metals having atomic numbers 57-71, especially cerium, or mixtures of any of the foregoing metals.
  • Collier et al. U.S. Patent Appl. Publ. No. 2003/0221362, discloses a fuel additive composition for a diesel engine equipped with a particulate trap, the composition comprising a hydrocarbon solvent and an oil-soluble metal carboxylate or metal complex derived from a carboxylic acid containing not more than 125 carbon atoms.
  • the metal may be an alkali metal, an alkaline earth metal, a metal of Group IVB, VIIB, VIIIB, IB, HB, or a rare earth metal, including cerium, or mixtures of any of the foregoing metals.
  • Caprotti et al. U.S. Patent Appl. Publ. No. 2004/0035045, discloses a fuel additive composition for a diesel engine equipped with a particulate trap.
  • the composition comprises an oil-soluble or oil-dispersible metal salt of an acidic organic compound and a stoichiometric excess of metal.
  • the composition provides 1-25 ppm of metal, which is selected from the group consisting of Ca, Fe, Mg, Sr, Ti, Zr, Mn, Zn, and Ce.
  • Caprotti et al. U.S. Patent Appl. Publ. No. 2005/0060929, discloses a diesel fuel composition stabilized against phase separation that contains a colloidally dispersed or solubilized metal catalyst compound and 5-1000 ppm of a stabilizer that is an organic compound having a lipophilic hydrocarbyl chain attached to at least two polar groups, at least one of which is a carboxylic acid or carboxylate group.
  • the metal catalyst compound comprises one or more organic or inorganic compounds or complexes of Ce, Fe, Ca, Mg, Sr, Na, Mn, Pt, or mixtures thereof.
  • Caprotti et al. U.S. Patent Appl. Publ. No. 2006/0000140, discloses a fuel additive composition that comprises at least one colloidal metal compound or species and a stabilizer component that is the condensation product of an aldehyde or ketone and a compound comprising one or more aromatic moieties containing a hydroxyl substituent and a further substituent chosen from among hydrocarbyl, -COOR, or -COR, R being hydrogen or hydrocarbyl.
  • the colloidal metal compound preferably comprises at least one metal oxide, preferred oxides being iron oxide, cerium dioxide, or cerium-doped iron oxide.
  • Scattergood International Publ. No. WO 2004/065529, discloses a method for improving the fuel efficiency of fuel for an internal combustion engine that comprises adding to the fuel cerium dioxide and/or doped cerium dioxide and, optionally, one or more fuel additives.
  • Cerium-containing nanoparticles can be prepared by a variety of techniques known in the art. Regardless of whether the synthesized nanoparticles are made in a hydrophilic or hydrophobic medium, the particles normally require a stabilizer to prevent undesirable agglomeration.
  • Chane-Ching et al. U.S. Patent No. 6,271,269 discloses a process for preparing storage-stable organic sols that comprises: reacting a base reactant with an aqueous solution of the salt of an acidic metal cation to form an aqueous colloidal dispersion containing excess hydroxyl ions; contacting the aqueous colloidal dispersion with an organic phase comprising an organic liquid medium and an organic acid; and separating the resulting aqueous/organic phase mixture into an aqueous phase and a product organic phase.
  • Preferred metal cations are cerium and iron cations.
  • the colloidal particulates have hydrodynamic diameters in the range of 5-20 nanometers.
  • Chane-Ching U.S. Patent No. 6,649,156, discloses an organic sol containing cerium dioxide particles that are made by a thermal hydrolysis process; an organic liquid phase; and at least one amphiphilic compounds chosen from polyoxyethylenated alkyl ethers of carboxylic acids, polyoxyethylenated alkyl ether phosphates, dialkyl sulfosuccinates, and quaternary ammonium compounds.
  • the water content of the sols may not be more than 1%.
  • the mean crystallite size is about 5 nm, while the particle agglomerates of these crystallites range in size from 200 to 10 nm.
  • Chane-Ching U S. Patent No. 7,008,965 discloses an aqueous colloidal dispersion of a compound of cerium and at least one other metal, the dispersion having a conductivity of at most 5 mS/cm and a pH between 5 and 8.
  • Chane-Ching U.S. Patent Appl. Publ. No. 2004/0029978 (abandoned December 7, 2005), discloses a surfactant formed from at least one nanoparticle that has amphiphilic characteristics and is based on a metal oxide, hydroxide and/or oxyhydroxide, on the surface of which organic chains with hydrophobic characteristics are bonded.
  • the metal is preferably selected from among cerium, aluminum, titanium or silicon, and the alkyl chain comprises 6-30 carbon atoms, or polyoxyethylene monoalkyl ethers of which the alkyl chain comprises 8-30 carbon atoms and the polyoxyethylene part comprises 1-10 oxyethylene groups.
  • the particle is an isotopic or spherical particle having an average diameter of 2-40 nm.
  • Example 1 describes the preparation of a cerium dioxide colloidal solution from cerium acetate and an organic phase that includes Isopar hydrocarbon mixture and isostearic acid. The resulting cerium dioxide particles had a dso of 2.5 nm, and the size of 80% of the particles was in the range of 1-4 nm.
  • Zhou et al. U. S. Patent No. 7,025,943, discloses a method for producing cerium dioxide crystals that comprises: mixing a first solution of a water-soluble cerium salt with a second solution of alkali metal or ammonium hydroxide; agitating the resulting reactant solution under turbulent flow conditions while concomitantly passing gaseous oxygen through the solution; and precipitating cerium dioxide particles having a dominant particle size within the range of 3-100 nm.
  • the particle size is stated to be around 3-5 nm. No mention is made of a stabilizing agent and it is anticipated that the sols will eventually agglomerate and settle.
  • Woodhead, James, L. U. S. Patent No. 4,231,893 teaches the preparation of an aqueous dispersion of ceria by the acid treatment of Ce(OH) 4 which has been obtained from the peroxide treatment of Ce +3 in base. No sizing data are provided and at the required pH for stabilization, 1.5, the likely stabilizer is NO3 " anion.
  • Noh et al. U.S. Patent Appl. Publ. No. 2004/0241070, discloses a method for preparing single crystalline cerium dioxide nanopowder comprising: preparing cerium hydroxide by precipitating a cerium salt in the presence of a solvent mixture of organic solvent and water, preferably in a ratio of about 0.1 :1 to about 5:1 by weight; and hydrothermally reacting the cerium hydroxide.
  • the nanopowder has a particle size of about 30-300 nm.
  • Chan U.S. Patent Appl. Publ. No. 2005/0031517, discloses a method for preparing cerium dioxide nanoparticles that comprises: rapidly mixing an aqueous solution of cerium nitrate with aqueous hexamethylenetetramine, the temperature being maintained at a temperature no higher than about 320 ° K while nanoparticles form in the resulting mixture; and separating the formed nanoparticles.
  • the mixing apparatus preferably comprises a mechanical stirrer and a centrifuge.
  • the prepared cerium dioxide particles are reported to have a diameter of about 12 nm.
  • Ying et al. U.S. Patent Nos. 6,413,489 and 6,869,584, disclose the synthesis by a reverse micelle technique of nanoparticles that are free of agglomeration and have a particle size of less than 100 nm and a surface area of at least 20 m 2 /gm.
  • the method comprises introducing a ceramic precursor that includes barium alkoxide and aluminum alkoxide in the presence of a reverse emulsion.
  • a related publication Ying et al., U.S. Patent Appl. Publ. No. 2005/0152832, discloses the synthesis, by a reverse micelle technique within an emulsion having a 1 - 40% water content, of nanoparticles that are free of agglomeration and have a particle size of less than 100 nm.
  • the nanoparticles are preferably metal oxide particles, which can be used to oxidize hydrocarbons.
  • a process for preparing a colloidal dispersion of the cerium (IV) compound produces particles with a hydrodynamic diameter between about 1 nm and about 60 nm, suitably between about 1 nm and about 10 nm, and desirably between about 3 nm and 8 nm.
  • Seal et al. U.S. Patent No. 7,419,566
  • the particles which are prepared by a reverse micelle process using toluene as the oil phase and AOT as the surfactant, have diameters in the range of about 2-7 nm, the mean being about 5 nm.
  • a grain diameter of 10 nm will experience a lattice strain or change in the lattice constant of 0.0103 A or 1.91%, whereas a 1 nm diameter grain will experience a change of 0.031 A or 5.73 percent.
  • CeO 2 can act as a catalytic oxygen storage material, described by equation 1, is governed in part by the CeO 2 particle size.
  • the lattice parameter increases dramatically with decreasing crystallite size (up to 0.45% at 6 nm, see for example Zhang, et al. , Applied Physics Letters, 80 1, 127 (2002)).
  • the associated size-induced lattice strain is accompanied by an increase in surface oxygen vacancies that results in enhanced catalytic activity. This inverse size- dependent activity provides not only for more efficient fuel cells, but better oxidative properties when used in the combustion of petroleum fuels.
  • cerium dioxide doped with components that result in the formation of additional oxygen vacancies being formed Eq. 1.
  • the dopant ion should be divalent or trivalent, i.e., a divalent or trivalent ion of an element that is a rare earth metal, a transition metal or a metal of Group HA, IIIB, VB, or VIB of the Periodic Table.
  • the requirement for crystal charge neutrality using these lower valence cations will drive Eq. 1 to the right, i.e., higher extent of oxygen vacancy formation.
  • Metal dopant ions with smaller ionic radii than Ce +4 (0.97 A in an octahedral configuration) will also aid in oxygen vacancy formation since this process reduces two adjacent Ce +4 ions (one surface and one subsurface) to Ce +3 whose resultant larger ionic radius, 1.143 A, expands the lattice, thereby causing lattice strain.
  • Zr +4 ionic radius 0.84 A
  • Cu +2 ionic radius of six coordinate octahedral configuration is 0.73 A
  • four coordinate tetrahedral 0.57 A will relieve some of this lattice strain.
  • Zr allows the formation of two adjacent surface Ce +3 species (rather than one surface and one subsurface), which may be important for very small particles where approximately 50% of the ions are surface ions.
  • substitutional ion doping is preferred to interstitial ion doping, where the dopants occupy spaces between the normal lattice positions.
  • doping refers to n or p type impurities present in the parts-per-million range.
  • doped crystal can have one or more metal dopant ions present in the CeO 2 crystal at concentrations greater than 20,000 ppm up to 800,000 ppm (or 80% of the cerium sub- lattice).
  • a lattice engineered cerium dioxide crystal could have cerium present as the minor metal component.
  • Pulsed neutron diffraction techniques were used by E. Mamontov, et al. J. Phys. Chem. B 2000, 104, 1110-1116 to study ceria and ceria-zirconia solid solutions. These studies established for the first time the correlation between the concentration of vacancy-interstitial oxygen defects and the oxygen storage capability. They postulate that the preservation of oxygen defects, which Zr aids, is necessary to ameliorate the degradation of OSC as a function of thermal aging. ZrO 2 was present at 30.5 mole %, and the calcined particles had a diameter of approximately 40 nm, based upon BET surface area measurements.
  • Iron is another metal ion that has imbued CeO 2 nanoparticles with enhanced catalytic activity.
  • the Fe-doped ceria is made by a co-precipitation method that produces particles in the 30 nm diameter range.
  • Illustrative Examples 9 and 10 of U.S. Patent Appl. Publ. No. 2005/0152832 describe the preparation of, respectively, cerium-doped and cerium-coated barium hexaaluminate particles.
  • Example 13 describes the oxidation of methane with the cerium- coated particles.
  • Talbot et al. U.S. Patent No. 6,752,979, the disclosure of which is incorporated herein by reference, describes a method of producing metal oxide particles having nano-sized grains that consists of: mixing a solution containing one or more metal cations with a surfactant under conditions such that surfactant micelles are formed within the solution, thereby forming a micellar liquid; and heating the micellar liquid to remove the surfactant and form metal oxide particles having a disordered pore structure.
  • the metal cations are selected from the group consisting of cations from Groups IA, 2A, 3 A, 4A, 5 A, and 6A of the Periodic Table, transition metals, lanthanides, actinides, and mixtures thereof.
  • Preparations of particles of cerium dioxide and mixed oxides containing cerium and one or more other metals are included in the illustrative examples.
  • Illustrative example 9 of U.S. Patent Nos. 6,413,489 and 6,869,584, the disclosures of which are incorporated herein by reference, describes the inclusion of cerium nitrate in the emulsion mixture to prepare cerium-doped barium hexaaluminate particles, which were collected by freeze drying and calcined under air to 500 ° C and 800 ° C. The resulting particles had grain sizes of less than 5 nm and 7 nm at 500 ° C and 800 ° C, respectively.
  • Illustrative example 10 describes the synthesis of cerium-coated barium hexaaluminate particles. Following calcination, the cerium-coated particles had grain sizes of less than 4 nm, 6.5 nm, and 16 nm at 500 ° C, 800 ° C, and 1100 ° C, respectively.
  • Wakefield U.S. Patent No. 7,169,196 B2, the disclosure of which is incorporated herein by reference, describes a fuel comprising cerium dioxide particles that have been doped with a divalent or trivalent metal or metalloid that is a rare earth metal, a transition metal, or a metal of Group Ha, IIIB, VB, or VIB of the Periodic Table. Copper is disclosed as a preferred dopant.
  • a typical chemical reactor that might be used to prepare cerium dioxide includes a reaction chamber that includes a mixer (see, for example, Fig. 1 in Zhou et al. U.S. Patent No. 7,025,943, the disclosure of which is incorporated herein by reference).
  • a mixer typically includes a shaft, and propeller or turbine blades attached to the shaft, and a motor that turns the shaft, such that the propeller is rotated at high speed (1000 to 5000 rpm).
  • the shaft can drive a flat blade turbine for good meso mixing (micro scale) and a pitched blade turbine for macro mixing (pumping fluid through out the reactor).
  • Such a device is described in Antoniades, U.S. Patent No. 6,422,736, the disclosure of which is incorporated herein by reference.
  • the described reactor is useful for fast reactions such as that shown by the equation below, wherein the product, AgCl, is a crystalline material having a diameter on the order of several hundred nanometers up to several thousand nanometers.
  • Cerium dioxide particles prepared using this type of mixing are often too large to be useful for certain applications. It is highly desirable to have the smallest cerium dioxide particles possible as their catalytic propensity, i.e., their ability to donate oxygen to a combustion system (cf. equation 1), increases with decreasing particle size, especially for particles having a mean diameter of less than 10 nm.
  • PCT/US2007/077545 METHOD OF PREPARING CERIUM DIOXIDE NANOPARTICLES, filed September, 4, 2007, describes a mixing device that is capable of producing CeO 2 nanoparticles down to 1.5 nm, in high yield and in very high suspension densities.
  • the reactor includes inlet ports for adding reactants, a propeller, a shaft, and a motor for mixing.
  • the reaction mixture is contained in a reactor vessel. Addition to the vessel of reactants such as cerium nitrate, an oxidant, and hydroxide ion can result in the formation of CeO 2 nanoparticles, which are initially formed as very small nuclei.
  • nuclei causes the nuclei to circulate; as the nuclei continuously circulate through the reactive mixing regime, they grow (increase in diameter) as they incorporate fresh reactants. Thus, after an initial steady state concentration of nuclei is formed, this nuclei population is subsequently grown into larger particles in a continuous manner. Unless grain growth restrainers are employed to terminate the growth phase, this nucleation and growth process is not desirable if one wishes to limit the final size of the particles while still maintaining a high particle suspension density.
  • colloid mills In contrast to batch reactors, colloid mills typically have flat blade turbines turning at 10,000 rpm, whereby the materials are forced through a screen whose holes can vary in size from fractions of a millimeter to several millimeters. Generally, no chemical reaction is occurring, but only a change in particle size brought about by milling. In certain cases, particle size and stability can be controlled thermodynamically by the presence of a surfactant.
  • a surfactant for example, Langer et al., in U.S. Patent No. 6,368,366 and U.S. Patent No. 6,363,237, the disclosures of which are incorporated herein by reference, describe an aqueous microemulsion in a hydrocarbon fuel composition made under high shear conditions. However, the aqueous particle phase (the discontinuous phase in the fuel composition) has a large size, on the order of 1000 nm.
  • Colloid mills are not useful for reducing the particle size of large cerium dioxide particles because the particles are too hard to be sheared by the mill in a reasonable amount of time.
  • the preferred method for reducing large agglomerated cerium dioxide particles from the micron size down into the nanometer size is milling for several days on a ball mill in the presence of a stabilizing agent. This is a time consuming, expensive process that invariably produces a wide distribution of particle sizes.
  • Aqueous precipitation may offer a convenient route to cerium nanop articles.
  • cerium dioxide nanoparticles must exhibit stability in a nonpolar medium, for example, diesel fuel.
  • Most stabilizers used to prevent agglomeration in an aqueous environment are ill suited to the task of stabilization in a nonpolar environment. When placed in a nonpolar solvent, such particles tend to immediately agglomerate and, consequently, lose some, if not all, of their desirable nanoparticulate properties.
  • cerium nanoparticles to provide a high temperature oxidation resistant coating has been reported, for example, in "Synthesis Of Nano Crystalline Ceria Particles For High Temperature Oxidization Resistant Coating," S. Seal et al., Journal of Nanoparticle Research, 4, pp 433-438 (2002).
  • the deposition of cerium dioxide on various surfaces has been investigated, including Ni, chromia and alumina alloys, and stainless steel and on Ni, and Ni-Cr coated alloy surfaces. It was found that a cerium dioxide particle size of 10 nm or smaller is desirable. Ceria particle incorporation subsequently inhibits oxidation of the metal surface.
  • cerium oxide- and doped cerium oxide-based fuel additives have improved fuel combustion of diesel engines; however further improvements are still needed. It would be desirable to formulate these fuel additives for diesel engines that provide further improved fuel combustion by taking advantage of even smaller, sub 5 nm nanoparticles of cubic CeO 2 with higher specific surface areas. The increased oxygen storage capability enabled by the inclusion of transition metals at these grain sizes is also highly desirable. In addition, protection of engines from wear, reduced engine friction, and greater lubricity, with simultaneously improved fuel efficiency would be tremendously beneficial. Summary of the Invention
  • the present invention is directed to a process for making lattice engineered cerium dioxide nanoparticles containing at least one transition metal (M) that comprises: (a) providing an aqueous reaction mixture comprising a source of cerous ion, a source of one or more transition metal ions (M), a source of hydroxide ion, at least one nanoparticle stabilizer, and an oxidant at an initial temperature in the range of about 20 0 C to about 95°C; (b) mechanically shearing the mixture and causing it to pass through a perforated screen, thereby forming a suspension of cerium hydroxide nanoparticles; and (c) providing temperature conditions effective to enable oxidation of cerous ion to eerie ion, thereby forming a product stream comprising transition metal-containing cerium dioxide nanoparticles, Cei -x M x ⁇ 2 .
  • the cerium dioxide nanoparticles thus obtained have a cubic fluorite structure, a mean hydrodynamic diameter in the range of about
  • the present invention is further directed to a process for forming a homogeneous dispersion containing stabilized transition metal-containing cerium dioxide nanoparticles, Cei- x M x ⁇ 2, that comprises: (a) providing an aqueous mixture that includes stabilized transition metal-containing cerium dioxide nanoparticles, Cei -x M x ⁇ 2, having a cubic fluorite structure, a mean hydrodynamic diameter in the range of about 1 nm to about 10 nm, and a geometric diameter of about 1 nm to about 4 nm; (b) concentrating the aqueous mixture that includes the stabilized transition metal-containing cerium dioxide nanoparticles, thereby forming an aqueous concentrate; (c) removing substantially all the water from the aqueous concentrate, thereby forming a substantially water-free concentrate of the stabilized transition metal-containing cerium dioxide nanoparticles; (d) adding an organic diluent to the substantially water-free concentrate, thereby forming an organic concentrate of the stabilized transition metal
  • FIGS. IA and IB are, respectively, a TEM image and a particle size frequency analysis by TEM of CeO 2 nanoparticles prepared by non-isothermal precipitation, as described in Example 1.
  • FIG 2 is an X-ray powder diffraction spectrum of cerium dioxide nanoparticles prepared as described in Example 1.
  • FIG 3 A is a TEM image of 1.1 nm CeO 2 nanoparticles prepared as described in Example 2;
  • FIG 3B is an electron diffraction pattern of these 1.1 nm particles;
  • FIG 3 C is TABLE 1, containing calculated vs measured electron diffraction intensities for cubic and hexagonal CeO 2 and Ce 2 ⁇ 3 lattices.
  • FIGS. 4A and 4B are, respectively, a TEM image and a particle size- frequency analysis by TEM of isothermally precipitated CeO 2 nanoparticles, prepared by a triple jet process as described in Example 3.
  • FIGS. 5A and 5B are, respectively, a TEM image and a particle size- frequency analysis by TEM of isothermally precipitated Cu-containing CeO 2 nanoparticles, prepared as described in Example 4.
  • FIGS. 6A and 6B are, respectively, a TEM image and a particle size- frequency analysis by TEM of isothermally precipitated Fe-containing CeO 2 nanoparticles, prepared as described in Example 5.
  • FIGS. 7A and 7B are, respectively, a TEM image and a particle size- frequency analysis by TEM of isothermally precipitated Zr-containing CeO 2 nanoparticles, prepared as described in Example 6.
  • FIGS. 8A and 8B are respectively, a TEM image and a particle size- frequency analysis by TEM of isothermally precipitated CeO 2 nanoparticles containing Zr and Fe, prepared as described in Example 7.
  • FIG 8C are x-ray diffraction spectra of isothermally precipitated CeO 2 nanoparticles and of isothermally precipitated CeO 2 nanoparticles containing Zr and Fe, prepared as described in Example 7.
  • FIG 9 is a field emission gun TEM lattice image Of CeO 2 nanoparticles containing Zr and Fe, prepared as described in Example 7. Detailed Description of the Invention
  • transition metal is understood to encompass the 40 chemical elements 21 to 30, 39 to 48, 72 to 80, which are included in Periods 4, 5, 6 , respectively, of the Periodic Table
  • the present invention provides a process for making transition metal ion- containing cerium dioxide (CeO 2 ) nanoparticles that comprises: (a) providing an aqueous reaction mixture comprising a source of cerous ion and one or more transition metal ions, a source of hydroxide ion, at least one nanoparticle stabilizer, and an oxidant; (b) mechanically shearing the mixture and causing it to pass through a perforated screen, thereby forming a suspension of cerium hydroxide nanoparticles; and (c) providing temperature conditions effective to enable oxidation of cerous ion to eerie ion, thereby forming a product stream comprising transition metal-containing cerium dioxide nanoparticles, Cei -x M x ⁇ 2 , that have the cubic fluorite structure, with a mean hydrodynamic diameter in the range of about 1 nm to about 10 nm and a geometric diameter of about 1 nm to about 4 nm.
  • Crystalline, cerium dioxide particles containing one or more transition metal ions and having a monomodal size distribution and a monodisperse size frequency distribution can be selectively prepared within this size range.
  • the single crystalline particles contain either two unit cells per edge for 1.1 nm particles up to 5 unit cells per edge for 2.7 nm particles particles depending upon the conditions of preparation.
  • the word crystalline refers to particles that are not composed of multiple, agglomerated crystallites of various sizes but rather a single crystal of well defined dimensions dictated by the number of constituent unit cells.
  • the present invention further provides for a continuous process for producing crystalline cerium dioxide CeO 2 nanoparticles containing one or more transition metal ions and having a mean hydrodynamic diameter of about 1 nm to about 10 nm, wherein the process comprises the step of combining cerous ion, one or more transition metal ions, an oxidant, at least one nanoparticle stabilizer, and hydroxide ion within a continuous reactor.
  • the present invention also provides a process for making cerium dioxide nanoparticles that comprises the steps of: (a) providing an aqueous first reaction mixture comprising a source of cerous ion, one or more transition metal ions and at least one nanoparticle stabilizer; (b) stirring the first reaction mixture while adding an oxidant, thereby producing a second reaction mixture; (c) adding a source of hydroxide ion to the second reaction mixture while subjecting it to mechanical shearing, thereby forming a third reaction mixture; and (d) heating the third reaction mixture to a temperature between about 50 0 C and about 100 0 C, thereby producing crystalline cerium dioxide nanoparticles that contain one or more transition metal ions and are substantially monomodal and uniform in size frequency distribution.
  • the present invention further provides a process for forming a homogeneous mixture that includes the aforementioned crystalline cerium dioxide nanoparticles, at least one nanoparticle stabilizer, at least one surfactant, a glycol ether mixture, and a nonpolar medium.
  • the process comprises the steps of: (a) providing an aqueous mixture that includes stabilized crystalline cerium dioxide nanoparticles produced by close association of the nanoparticle stabilizer with the crystalline cerium dioxide nanoparticles; (b) concentrating the aqueous mixture including stabilized crystalline cerium dioxide nanoparticles to form an aqueous concentrate; and (c) removing substantially all of the water by solvent shifting from an aqueous environment to an glycol ether environment, combining the surfactant and optionally a co-surfactant with the solvent shifted concentrate in the presence of the nonpolar medium, thereby forming the homogeneous mixture.
  • eerie ion reacts to form cerium hydroxide, which on heating is converted to crystalline cerium dioxide.
  • the temperature in the reaction vessel is maintained between about 50 0 C and about 100 0 C, more preferably about 65-95°C, most preferably about 85°C. Time and temperature can be traded off, higher temperatures typically reducing the time required for conversion of the hydroxide to the oxide.
  • the cerium hydroxide is converted to crystalline cerium dioxide, and the temperature of the reaction vessel is lowered to about 15 -25 0 C.
  • the crystalline cerium dioxide nanoparticles are concentrated, and the unreacted cerium and waste by-products such as ammonium nitrate are removed, most conveniently, for example, by diafiltration.
  • a method of making crystalline cerium dioxide nanoparticles containing one or more transition metal ions includes: providing an aqueous reaction mixture comprising cerous ion, one or more transition metal ions, hydroxide ion, a stabilizer or combination of stabilizers, and an oxidant, the reaction being carried out at a temperature effective to generate small nuclei size and to achieve subsequent oxidation of cerous ion to eerie ion and enable the nuclei to be grown into nano metric cerium dioxide.
  • the reaction mixture is subjected to mechanical shearing, preferably by causing it to pass through a perforated screen, thereby forming a suspension of crystalline cerium dioxide nanoparticles having a mean hydrodynamic diameter in the range of about 1 nm to about 10 nm. While the particle diameter can be controlled within the range of 1.5 nm to 25 nm, preferably the crystalline cerium dioxide nanoparticles have a mean hydrodynamic diameter of about 10 nm or less, more preferably about 8 nm or less, most preferably, about 6 nm. Desirably, the nanoparticles comprise one or at most two primary crystallites per particle edge, each crystallite being on average 2.5 nm (approximately 5 unit cells).
  • the resulting nanoparticle size frequency in substantially monodisperse, i.e., having a coefficient of variation (COV) less than 25%, where the COV is defined as the standard deviation divided by the mean.
  • COV coefficient of variation
  • Mechanical shearing includes the motion of fluids upon surfaces such as those of a rotor, which results in the generation of shear stress.
  • the laminar flux on a surface has a zero velocity, and shear stress occurs between the zero-velocity surface and the higher- velocity flow away from the surface.
  • the current invention employs a colloid mill, which is normally used for milling microemulsions or colloids, as a chemical reactor to produce cerium dioxide nanoparticles.
  • a colloid mill which is normally used for milling microemulsions or colloids, as a chemical reactor to produce cerium dioxide nanoparticles.
  • useful colloid mills include those described by Korstvedt, U.S. Patent No. 6,745,961 and U.S. Patent No. 6,305,626, the disclosures of which are incorporated herein by reference.
  • the reactants include an aqueous solution of a cerous ion source, for example, cerous nitrate; an oxidant such as hydrogen peroxide or molecular oxygen; and a stabilizer such as, for example, 2-[2-(2-methoxyethoxy)ethoxy] acetic acid.
  • a two-electron oxidant such as peroxide is present, preferably in at least one-half the molar concentration of the cerium ion.
  • the hydroxide ion concentration is preferably at least twice, more preferably three times, or may even be five times the molar cerium ion concentration.
  • the reaction chamber is maintained at a temperature sufficiently low to generate small cerous hydroxide nuclei size, which can be grown into nanometric crystalline cerium dioxide particles after a subsequent shift to higher temperatures, resulting in conversion of the cerous ion into the eerie ion state.
  • the temperature is suitably about 25°C or less, although higher temperatures may be used without a significant increase in particle size.
  • a source of cerous ion, one or more transition metal ions, a nanoparticle stabilizer, and an oxidant are placed in the reactor, and a source of hydroxide ion such as ammonium hydroxide is rapidly added with stirring, preferably over a time period of about 10 minutes or less. Under certain conditions such as a single jet addition of ammonia to metal ions, about 20 seconds or less is preferred, even more preferably about 15 seconds or less.
  • a source of hydroxide ion and an oxidant is placed in the reactor, and a source of cerous ion and one or more transition metal ions are added over a period of about 15 seconds up to 20 minutes.
  • the stabilizers are placed in the reaction vessel, and the cerous nitrate with one or more transition metal ions are simultaneously introduced into the reaction chamber with a separate jet of ammonium hydroxide at the optimum molar stoichiometric ratio of 2:1 , 3: 1 or even 5: 1 OH: Ce.
  • Cerous ion reacts with the oxidant in the presence of hydroxide ion to form cerium hydroxide, which can be converted by heating to crystalline cerium dioxide.
  • the temperature in the reaction vessel is maintained between about 50 0 C and about 100 0 C, preferably about 65-85°C, more preferably about 70 0 C.
  • the incorporation of certain transition metal ions such as Zr and Cu typically require higher temperatures, about 85 0 C.
  • the doped cerium hydroxide has been substantially converted to crystalline cerium dioxide, and the temperature of the reaction vessel is lowered to about 15 -25 0 C.
  • the time and temperature variables may be traded off, higher temperatures generally requiring shorter reaction times.
  • the suspension of cerium dioxide nanoparticles is concentrated, and the unreacted cerium and waste by-products such as ammonium nitrate are removed, which may be conveniently accomplished by diafiltration.
  • the nanoparticle stabilizer is a critical component of the reaction mixture.
  • the nanoparticle stabilizer is water-soluble and forms weak bonds with cerium ion.
  • K BC represents the binding constant of the nanoparticle stabilizer to cerium ion in water.
  • Log K B c for the nitrate ion is 1 and for hydroxide ion is 14. Most desirably, log K BC lies within this range, preferably in the middle of this range.
  • Useful nanoparticle stabilizers include alkoxy substituted carboxylic acids, ⁇ -hydroxyl carboxylic acids, ⁇ - keto carboxylic acids such as pyruvic acid, and small organic polyacids such as tartaric acid and citric acid.
  • alkoxylated carboxylic acids include; methoxy acetic acid, 2-(methoxy)ethoxy acetic acid and 2-[2-(2-methoxyethoxy)ethoxy] acetic acid (MEEA).
  • MEEA 2-methoxyethoxyethoxyethoxy] acetic acid
  • examples include lactic acid, gluconic acid and 2-hydroxybutanoic acid.
  • Polyacids include ethylenediaminetetraacetic acid (EDTA), tartaric acid, and citric acid.
  • EDTA ethylenediaminetetraacetic acid
  • Combinations of compounds with large K B c such as EDTA with weak K B C stabilizers such as lactic acid are also useful at particular ratios. Large K B C stabilizers such as gluconic acid may be used at a low level, or with weak K B C stabilizers such as lactic acid.
  • the nanoparticle stabilizer includes a compound of formula (Ia).
  • R represents hydrogen, or a substituted or unsubstituted alkyl group or aromatic group such as, for example, a methyl group, an ethyl group or a phenyl group. More preferably, R represents a lower alkyl group such as a methyl group.
  • R 1 represents hydrogen or a substituent group such as an alkyl group.
  • n represents an integer of 0-5, preferably 2, and Y represents H or a counterion such as an alkali metal, for example, Na + or K + .
  • the stabilizer binds to the nanoparticles and prevents agglomeration of the particles and the subsequent formation of large clumps of particles.
  • the nanoparticle stabilizer is represented by formula (Ib), wherein each R 2 independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic group.
  • X and Z independently represent H or a counterion such as Na + or K + , and p is 1 or 2.
  • Useful nanoparticle stabilizers are also found among ⁇ -hydroxysubstituted carboxylic acids such as lactic acid and among the polyhydroxysubstituted acids such as gluconic acid.
  • the nanoparticle stabilizer does not include the element sulfur, since sulfur-containing materials may be undesirable for certain applications.
  • sulfur-containing materials may be undesirable for certain applications.
  • the use of a sulfur-containing stabilizer such as AOT may result in the undesirable emission of oxides of sulfur after combustion.
  • the size of the resulting cerium dioxide particles can be determined by dynamic light scattering, a measurement technique for determining the hydrodynamic diameter of the particles.
  • the hydrodynamic diameter (cf. B. J. Berne and R. Pecora, "Dynamic Light Scattering: With Applications to Chemistry, Biology and Physics", John Wiley and Sons, NY 1976 and “Interactions of Photons and Neutrons with Matter", S. H. Chen and M. Kotlarchyk, World Scientific Publishing, Singapore, 1997), which is slightly larger than the geometric diameter of the particle, includes both the native particle size and the solvation shell surrounding the particle. When a beam of light passes through a colloidal dispersion, the particles or droplets scatter some of the light in all directions.
  • the intensity of the scattered light is uniform in all directions (Rayleigh scattering). If the light is coherent and monochromatic as, for example, from a laser, it is possible to observe time- dependent fluctuations in the scattered intensity, using a suitable detector such as a photo multiplier capable of operating in photon counting mode. These fluctuations arise from the fact that the particles are small enough to undergo random thermal Brownian motion, and the distance between them is therefore constantly varying. Constructive and destructive interference of light scattered by neighboring particles within the illuminated zone gives rise to the intensity fluctuation at the detector plane, which, because it arises from particle motion, contains information about this motion. Analysis of the time dependence of the intensity fluctuation can therefore yield the diffusion coefficient of the particles from which, via the Stokes Einstein equation and the known viscosity of the medium, the hydrodynamic radius or diameter of the particles can be calculated.
  • a continuous process for producing small, transition metal ion-containing crystalline cerium dioxide nanoparticles includes combining cerous ion, one or more transition metal ions, an oxidant, a nanoparticle stabilizer or stabilizer combination, and hydroxide ion within a continuous reactor, into which reactants and other ingredients are continuously introduced, and from which product is continuously removed.
  • Continuous processes are described, for example, in Ozawa, et al., U.S. Patent No. 6,897,270; Nickel, et al., U.S. Patent No. 6,723,138; Campbell, et al., U.S. Patent No.
  • a solvent such as water is often employed in the process.
  • the solvent dissolves the reactants, and the flow of the solvent can be adjusted to control the process.
  • mixers can be used to agitate and mix the reactants.
  • Any reactor that is capable of receiving a continuous flow of reactants and delivering a continuous flow of product can be employed. These reactors may include continuous-stirred-tank reactors, plug-flow reactors, and the like.
  • the reactants required to carry out the nanoparticle synthesis are preferably charged to the reactor in streams; i.e., they are preferably introduced as liquids or solutions.
  • the reactants can be charged in separate streams, or certain reactants can be combined before charging the reactor.
  • Reactants are introduced into the reaction chamber provided with a stirrer through one or more inlets.
  • the reactants include an aqueous solution of a cerous ion source, for example, cerous nitrate, a transition metal ion such as, for example, ferric nitrate or cupric nitrate; an oxidant such as hydrogen peroxide or molecular oxygen, including ambient air; and a stabilizer, such as, for example, 2-[2-(2- methoxyethoxy)ethoxy] acetic acid.
  • a two-electron oxidant such as hydrogen peroxide is present, preferably in at least one-half the molar concentration of the cerium ion.
  • molecular oxygen can be bubbled through the mixture.
  • the hydroxide ion concentration is preferably at least twice the molar cerium concentration.
  • a method of forming small cerium dioxide nanoparticles includes the step of forming a first aqueous reactant stream that includes cerous ion, for example, as cerium (III) nitrate, one or more transition metal ions, and an oxidant.
  • Suitable oxidants capable of oxidizing Ce(III) to Ce(IV) include, for example, hydrogen peroxide or molecular oxygen.
  • the first reactant stream also includes a nanoparticle stabilizer that binds to doped cerium dioxide nanoparticles, thereby preventing agglomeration of the particles. Examples of useful nanoparticle stabilizers were mentioned above.
  • the method further includes a step of forming a second aqueous reactant stream that includes a hydroxide ion source, for example, ammonium hydroxide or potassium hydroxide.
  • a hydroxide ion source for example, ammonium hydroxide or potassium hydroxide.
  • the second reactant stream further includes a stabilizer, examples of which were described previously. At least one of the first or second reactant streams, however, must contain a stabilizer or stabilizer combination.
  • the first and second reactant streams are combined to form a reaction stream. Initially, the temperature of the reaction stream is maintained sufficiently low to form small cerous hydroxide nuclei. Subsequently the temperature is raised so that oxidation of Ce(III) to Ce(IV) occurs in the presence of the oxidant, and the hydroxide is converted to the oxide, thereby producing a product stream that includes crystalline cerium dioxide.
  • the temperature for conversion from the hydroxide to the oxide is preferably in the range of about 50-100 0 C, more preferably about 60-90 0 C.
  • the first and second reactant streams are combined at a temperature of about 10-20 0 C, and the temperature is subsequently increased to about 60-90 0 C. Isothermal precipitation at an elevated temperature, e.g., 90 0 C, is an alternative method for producing small nanoparticles provided that the growth stage can be inhibited by a suitable molecular adsorbate (growth restrainer).
  • the lattice engineered, crystalline cerium dioxide nanoparticles in the product stream are concentrated, for example, by diafiltration techniques using one or more semi-porous membranes.
  • the product stream includes an aqueous suspension of transition metal-containing crystalline cerium dioxide nanoparticles that is reduced to a conductivity of about 5 mS/cm or less by one or more semi-porous membranes.
  • FIG 3 A schematic representation of a continuous reactor suitable for the practice of the invention is depicted in FIG 3 of PCT/US2007/77545, METHOD OF PREPARING CERIUM DIOXIDE NANOPARTICLES, filed September, 4, 2007.
  • the reactor 40 includes a first reactant stream 41 containing aqueous cerium nitrate.
  • An oxidant such as hydrogen peroxide is added to the reactant stream by means of inlet 42, and the reactants are mixed by mixer 43a.
  • To the resulting mixture is added stabilizer via inlet 45, followed by mixing by mixer 43b.
  • the mixture from mixer 43b then enters mixer 43c, where it is combined with a second reactant stream containing ammonium hydroxide from inlet 44.
  • the first and second reactant streams are mixed using a mixer 43 c to form a reaction stream that may be subjected to mechanical shearing by passing it through a perforated screen.
  • mixer 43 c comprises a colloid mill reactor, as described previously, that is provided with inlet ports for receiving the reactant streams and an outlet port 45.
  • the temperature of the mixer 43 c is maintained at a temperature in the range of about 10 0 C to about 25°C.
  • the mixture from 43c enters a reactor tube 45 that is contained in a constant temperature bath 46 that maintains tube 45 at a temperature of about 60-90 0 C. Crystalline cerium dioxide nanoparticles are formed in the reactor tube 45, which may include a coil 50.
  • the product stream then enters one or more diafiltration units 47, wherein the crystalline cerium dioxide nanoparticles are concentrated using one or more semi-porous membranes.
  • One or more diafiltration units may be connected in series to achieve a single pass concentration of product, or the units may placed in parallel for very high volumetric throughput.
  • the diafiltration units may be disposed both in series and parallel to achieve both high volume and rapid throughput.
  • stabilizer may be added to the second reactant stream via port 51 rather than to the first reactant stream via port 45.
  • the product stream of concentrated lattice engineered, crystalline cerium dioxide nanoparticles exiting the diafiltration unit 47 is solvent shifted into a substantially water-free environment of one or more glycol ethers.
  • This can be accomplished with dialysis bags or by running the aqueous nanoparticles though a diafiltration column with an organic diluent that preferably comprises one or more glycol ethers.
  • the organic diluent may further include an alcohol.
  • a useful diluent comprises a mixture of diethyl ene glycol mono methyl ether and 1 -methoxy-2-propanol.
  • the resulting solvent-shifted organic concentrate is combined with a surfactant such as oleic acid, followed by combination with a stream that includes a nonpolar solvent such as kerosene or ultra low sulfur diesel fuel, thereby forming a homogeneous dispersion of lattice engineered, crystalline cerium dioxide nanoparticles that is miscible with hydrocarbon fuels such as diesel.
  • a surfactant such as oleic acid
  • a stream that includes a nonpolar solvent such as kerosene or ultra low sulfur diesel fuel
  • the use of a continuous process for producing lattice engineered, crystalline cerium dioxide nanoparticles allows better control of the production of particle nuclei and their growth relative to that afforded by batch reactors.
  • the nuclei size can be controlled by the initial reagent concentration, temperature, and the ratio of nanoparticle stabilizer to reagent concentrations. Small nuclei are favored by low temperatures, less than about 2O 0 C, and high ratios of nanoparticle stabilizer to reagent concentrations. In this way, very small nanoparticles having a mean hydrodynamic diameter of less than about 10 nm, with geometrical particle diameters less than about 3 nm, can be produced in an economical manner.
  • the invention provides a method for formulating a homogeneous mixture that includes cerium dioxide (CeO 2 ) nanoparticles containing one or more transition metal ions, a nanoparticle stabilizer, a surfactant, glycol ethers, and a nonpolar solvent.
  • the nanoparticles have a mean hydrodynamic diameter of less than about 10 nm, more preferably less than about 8 nm, most preferably about 6 nm with geometric particle diameters (as determined by TEM) less than about 4 nm.
  • cerium dioxide particles can be prepared by reacting the hydrate of cerium (III) nitrate with hydroxide ion from, for example, aqueous ammonium hydroxide, thereby forming cerium (III) hydroxide, as shown in equation (3 a).
  • Cerium hydroxide can be oxidized to cerium (IV) dioxide with an oxidant such as hydrogen peroxide, as shown in equation (3b).
  • the analogous tris hydroxide stoichiometry is shown in equations (4a) and (4b).
  • the species Ce(OH) 2 (NO 3 ) or (NH 4 ) 2 Ce(NO 3 )s may initially be present, subsequently undergoing oxidation to cerium dioxide.
  • the transition metal containing, crystalline cerium dioxide particles are formed in an aqueous environment and combined with one or more nanoparticle stabilizers.
  • the cerium dioxide nanoparticles are either formed in the presence of the stabilizer(s), or a stabilizer(s) is added shortly after their formation.
  • Useful nanoparticle stabilizers include alkoxysubstituted carboxylic acids, ⁇ -hydroxyl carboxylic acids such as pyruvic acid, and small organic polycarboxylic acids. Examples of alkoxysubstituted carboxylic acids include methoxyacetic acid, 2-(methoxy)ethoxy acetic acid and 2-[2-(2-methoxyethoxy)ethoxy] acetic acid (MEEA).
  • the nanoparticle stabilizer includes a compound of formula (Ia) or formula (Ib), as described above.
  • the reaction mixture includes, in addition to transition metal containing, crystalline cerium dioxide particles, one or more salts, for example, ammonium nitrate and unreacted cerium nitrate.
  • the stabilized particles can be separated from these materials and salts by washing with 18 Mohm water in an ultrafiltration or diafiltration apparatus. Low ionic strength ( ⁇ 5 mS/cm) is highly desirable for particle formation and stabilization in a non-polar medium.
  • the washed, stabilized cerium dioxide nanoparticles may be concentrated, if desired, using a semi-porous membrane, for example, to form an aqueous concentrate of the nanoparticles.
  • the particles may be concentrated by other means as well, for example, by centrifugation.
  • the transition metal containing, crystalline cerium dioxide particles are concentrated by diafiltration.
  • the diafiltration technique utilizes ultrafiltration membranes, which can be used to completely remove, replace, or lower the concentration of salts in the nanoparticle-containing mixture.
  • the process selectively utilizes semi-permeable (semi-porous) membrane filters to separate the components of the reaction mixture on the basis of their molecular size.
  • a suitable ultrafiltration membrane would be sufficiently porous so as to retain the majority of the formed nanoparticles, while allowing smaller molecules such as salts and water to pass through the membrane. In this way, the nanoparticles and the associated bound stabilizer can be concentrated.
  • the materials retained by the filter, including the stabilized nanoparticles are referred to as the concentrate or retentate, the discarded salts and unreacted materials as the filtrate.
  • Pressure may be applied to the mixture to accelerate the rate at which small molecules pass through the membrane (flow rate) and to speed the concentration process.
  • Other means of increasing the flow rate include using a large membrane having a high surface area, and increasing the pore size of the membrane, but without an unacceptable loss of nanoparticles.
  • the membrane is selected so that the average pore size of the membrane is about 30% or less, 20 % or less, 10% or less, or even 5% or less than that of the mean diameter of the nanoparticles.
  • the pore diameter must be sufficient to allow passage of water and salt molecules. For example, ammonium nitrate and unreacted cerium nitrate should be completely or partially removed from the reaction mixture.
  • the average membrane pore size is sufficiently small to retain particles of 1.5 nm diameter or greater in the retentate. This would correspond to a protein size of approximately 3 kilodaltons.
  • the concentrate includes stabilized nanoparticles and residual water.
  • the concentration of cerium dioxide nanoparticles is preferably greater than about 0.5 molal, more preferably greater than about 1.0 molal, even more preferably greater than about 2.0 molal (approximately 35% solids in a given dispersion).
  • the concentrate is formed, most if not all of the water is removed by dialysis with glycol ethers. This is accomplished by placing the concentrate in a 2 kilodalton dialysis bag with a mixture of diethyl ene glycol methyl ether and l-methoxy-2- propanol, and letting the water exchange into the glycol ether medium while the glycol ether medium displaces the water in the nanoparticle dispersion. Several exchanges may be necessary (changes of glycol ether medium). Alternatively, the glycol ether mixture can be run with the aqueous transition metal containing, crystalline cerium dioxide particles through a diafiltration column and a solvent shift effected in this manner.
  • Glycol ether surfactants that contain both an ether group and an alcohol group includes compounds of formula (Ic), in which R 3 represents a substituted or unsubstituted alkyl group, and m is an integer of 1-8.
  • nonylphenyl ethoxylates having the formula, CgHi 9 CeH 4 (OCH 2 CH 2 ) H OH, wherein n is 4-6.
  • the mixture can be dispersed into a non-polar medium such as kerosene, which is compatible with most hydrocarbon fuels such as diesel and biodiesel.
  • a surfactant such as oleic acid and optionally a co-surfactant such as 1-hexanol before being added to the hydrocarbon diluent.
  • this composition of matter is not a reverse micelle water-in-oil emulsion , as there is very little water present; rather, the positive charge on the surface of the cerium nanoparticle has been complexed by the ether oxygen atoms and bound to the oppositely charged carboxylic acid.
  • the carboxylic acid is present in a chemisorbed state and facilitates the miscibility of the nanoparticle with a non-polar hydrocarbon diluent.
  • Other surface functionalization materials such as linoleic acid, stearic acid, and palmitic acid may be used in place of oleic acid.
  • the preferred materials are carboxylic acids with carbon chain lengths less than 20 carbon atoms but greater than 8 carbon atoms.
  • nonpolar diluents include, for example, hydrocarbons containing about 8 to 20 carbon atoms, for example, octane, nonane, decane and toluene, and hydrocarbon fuels such as gasoline, biodiesel, and diesel fuels.
  • Resistivity is the reciprocal of conductivity, which is the ability of a material to conduct electric current.
  • Conductivity instruments can measure conductivity by including two plates that are placed in the sample, applying a potential across the plates (normally a sine wave voltage), and measuring the current.
  • the basic unit of conductivity is the Siemens (S), or milli-Siemens (mS). Since cell geometry affects conductivity values, standardized measurements are expressed in specific conductivity units (mS/cm) to compensate for variations in electrode dimensions.
  • the present invention is further directed to a method for formulating a homogeneous mixture that includes transition metal-containing cerium dioxide nanoparticles, at least one nanoparticle stabilizer, one or more solvent shifted media such as glycol ethers, at least one surfactant, and a nonpolar diluent or solvent.
  • a first step provides an aqueous mixture that includes stabilized cerium dioxide nanoparticles, wherein molecules of the nanoparticle stabilizer are closely associated with the nanoparticles.
  • a second step includes concentrating the stabilized crystalline cerium dioxide nanoparticles while minimizing the ionic strength of the suspension to form an aqueous concentrate that is relatively free of anions and cations.
  • a third step removes the water associated with the nanoparticles using a non-ionic surfactant.
  • a final step includes combining this solvent shifted concentrate with a nonpolar solvent, containing a surfactant, thereby forming a substantially homogeneous mixture that is a thermodynamically stable, multicomponent, bi-phasic dispersion.
  • the substantially homogeneous thermodynamic dispersion contains a minimal amount of water at a level of preferably no more than about 0.5 wt.%.
  • the transition metal-containing cerium dioxide nanoparticles have a mean hydrodynamic diameter of preferably less than about 10 nm, more preferably less than about 8 nm, most preferably about 6 nm, and a geometric diameter of about 4 nm or less.
  • the cerium dioxide nanoparticles have a primary crystallite size of about 2.5 nm + 0.5 nm and comprise one or at most two crystallites per particle edge length.
  • the aqueous mixture is advantageously formed in a colloid mill reactor, and the nanoparticle stabilizer may comprise an ionic surfactant, preferably a compound that includes a carboxylic acid group and an ether group.
  • the nanoparticle stabilizer may comprise a surfactant of formula (Ia),
  • R represents hydrogen or a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic group
  • R 1 represents hydrogen or an alkyl group
  • Y represents H or a counterion
  • n is 0-5.
  • R represents a substituted or unsubstituted alkyl group
  • R 1 represents hydrogen
  • Y represents hydrogen
  • n is 2.
  • Another suitable nanoparticle stabilizer comprises a dicarboxylate of formula (Ib),
  • each R 2 independently represents hydrogen, a substituted or unsubstituted alkyl group or a substituted or unsubstituted aromatic group;
  • X and Z independently represent H or a counterion; and
  • p is lor 2.
  • nanoparticle stabilizers are included in the group consisting of lactic acid, gluconic acid enantiomers, EDTA, tartaric acid, citric acid, and combinations thereof.
  • Concentrating the aqueous mixture is preferably carried out using diafiltration, which results in the reduction in conductivity of said concentrated aqueous mixture to about 5 mS/cm or less.
  • the surfactant used to shift the stabilized transition metal containing, crystalline cerium dioxide particles from an aqueous to a non-aqueous environment may advantageously comprise a nonionic surfactant, preferably a compound comprising an alcohol group and an ether group, in particular, a compound of formula (Ic),
  • R 3 (OCH 2 CH 2 ) m OH (Ic) wherein R 3 represents a substituted or unsubstituted alkyl group; and m is an integer from l to 8.
  • the nonionic surfactant may also comprise a compound of formula (Id), R 3 ⁇ (OCH 2 CH 2 ) m OH (Id) wherein R 3 represents a substituted or unsubstituted alkyl group; ⁇ is an aromatic group; and m is an integer from 4 to 6.
  • the reaction mixture may further include a co-surfactant, preferably an alcohol.
  • surfactants that surface functionalize the nanoparticles.
  • Preferred surfactants are carboxylic acids such as oleic acid, linoleic acid, stearic acid, and palmitic acid.
  • the preferred materials are carboxylic acids with carbon chain lengths less than 20 carbon atoms but greater than 3 carbon atoms.
  • the nonpolar diluent included in the substantially homogeneous dispersion is advantageously selected from among hydrocarbons containing about 6-20 carbon atoms, for example, octane, decane, kerosene, toluene, naphtha, diesel fuel, biodiesel, and mixtures thereof.
  • hydrocarbons containing about 6-20 carbon atoms for example, octane, decane, kerosene, toluene, naphtha, diesel fuel, biodiesel, and mixtures thereof.
  • one part of the homogeneous dispersion is with at least about 100 parts of the fuel.
  • the transition metal is preferably selected from the group consisting of Fe, Mn, Cr, Ni, W, Co, V, Cu, Mo, Zr, Y and combinations thereof. Preferred transition metals are Zr or Y, more preferably combined with Fe. [00170] It may be beneficial to form a ceramic oxide coating on the interior surfaces of diesel engine cylinders in situ. The potential benefits of the coating include added protection of the engine from thermal stress; for example, CeO 2 melts at 2600 0 C, whereas cast iron, a common material used in the manufacture of diesel engines, melts at about 1200-1450 0 C.
  • a diesel engine having cylinder walls coated with cerium dioxide would be resistant to further oxidation (CeO 2 being already fully oxidized), thereby preventing the engine from "rusting.” This is important because certain additives used to reduce carbon emissions or improve fuel economy such as, for example, the oxygenates MTBE, ethanol and other cetane improvers such as peroxides, also increase corrosion when introduced into the combustion chamber, which may result in the formation of rust and degradation of the engine lifetime and performance.
  • the coating should not be so thick as to impede the cooling of the engine walls by the water recirculation cooling system.
  • the current invention provides transition metal-containing, crystalline, cerium dioxide nanoparticles having a mean hydrodynamic diameter of less than about 10 nm, preferably less than about 8 nm, more preferably 6 run or even less, that are useful as a fuel additive for diesel engines.
  • the surfaces of the cerium dioxide nanoparticles may be modified to facilitate their binding to an iron surface, and desirably would, when included in a fuel additive composition, rapidly form a ceramic oxide coating on the surface of diesel engine cylinders.
  • a transition metal having a binding affinity for iron is incorporated onto the surface of the cerium dioxide nanoparticles.
  • iron surfaces include those that exist in many internal parts of engines.
  • Suitable transition metals include Mn, Fe, Ni, Cr, W, Co, V, Cu, Zr, and Y.
  • the transition metal ion which is incorporated into the cerium dioxide nanoparticles by occupying a cerium ion lattice site in the crystal, may be introduced during the latter stages of the precipitation of cerium dioxide.
  • the transition metal ion can be added in combination with cerous ion, for example, in a single jet manner in which both cerous ion and transition metal ion are introduced together into a reactor containing ammonium hydroxide.
  • the transition and cerous ions can be added together with the simultaneous addition of hydroxide ion.
  • the transition metal-containing particles can also be formed in a double jet reaction of cerous ion with dissolved transition metal ion titrated against an ammonium hydroxide steam simultaneously introduced by a second jet. Critically, it is understood that sufficient nanoparticle stabilizer is present to prevent agglomeration of the nascent particles.
  • the surfactant/stabilizer combination may have the added benefit of aiding in the solvent shift process from the aqueous polar medium to the non-polar oil medium.
  • the charged surfactant compound plays a dominant role in the aqueous environment.
  • the charged compound is likely to be solubilized into the aqueous phase and washed out, and the uncharged compound becomes more important in stabilizing the reverse micelle emulsion.
  • Dicarboxylic acids and their derivatives so called “gemini carboxylates", where the carboxylic groups are separated by at most two methylene groups, are also useful cerium dioxide nanoparticle stabilizers. Additionally, C 2 -Cs alkyl, alkoxy and polyalkoxy substituted dicarboxylic acids are advantageous stabilizers.
  • nanoparticle stabilizer compounds preferably comprise organic carboxylic acids such as, for example, 2-[2-(2- methoxyethoxy)ethoxy] acetic acid (MEEA) and ethyl enediaminetetraacetic acid (EDTA), lactic acid, gluconic acid, tartaric acid, citric acid, and mixtures thereof.
  • organic carboxylic acids such as, for example, 2-[2-(2- methoxyethoxy)ethoxy] acetic acid (MEEA) and ethyl enediaminetetraacetic acid (EDTA), lactic acid, gluconic acid, tartaric acid, citric acid, and mixtures thereof.
  • Motor oil is used as a lubricant in various kinds of internal combustion engines in automobiles and other vehicles, boats, lawn mowers, trains, airplanes, etc.
  • Engines contain contacting parts that move against each other at high speeds, often for prolonged periods of time. Such rubbing motion causes friction, forming a temporary weld, immobilizing the moving parts. Breaking this temporary weld absorbs otherwise useful power produced by the motor and converts the energy to useless heat. Friction also wears away the contacting surfaces of those parts, which may lead to increased fuel consumption and lower efficiency and degradation of the motor.
  • a motor oil includes a lubricating oil, transition metal-containing, crystalline, cerium dioxide nanoparticles, desirably having a mean diameter of less than about 10 nm, more preferably about 5 nm, and optionally a surface adsorbed stabilizing agent.
  • Diesel lubricating oil is essentially free of water (preferably less than 300 ppm) but may be desirably modified by the addition of a cerium dioxide composition in which the cerium dioxide has been solvent shifted from its aqueous environment to that of an organic or non-polar environment.
  • the cerium dioxide compositions include nanoparticles having a mean diameter of less than about 10 nm, more preferably about 5 nm, as already described.
  • a diesel engine operated with modified diesel fuel and modified lubricating oil provides greater efficiency and may, in particular, provide improved fuel mileage, reduced engine wear or reduced pollution, or a combination of these features.
  • Metal polishing also termed buffing, is the process of smoothing metals and alloys and polishing to a bright, smooth mirror-like finish. Metal polishing is often used to enhance cars, motorbikes, antiques, etc. Many medical instruments are also polished to prevent contamination in irregularities in the metal surface. Polishing agents are also used to polish optical elements such as lenses and mirrors to a surface smoothness within a fraction of the wavelength of the light they are to manage. Smooth, round, uniform cerium dioxide particles of the present invention may be advantageously employed as polishing agents, and may further be used for planarization (rendering the surface smooth at the atomic level) of semiconductor substrates for subsequent processing of integrated circuits.
  • Example 1 Preparation of Cerium Dioxide Nanoparticles by Single- Jet Addition.
  • the pH was 3.9 at 25 0 C at 3 minutes after pumping the NH 4 OH into the reactor.
  • the temperature of the reactor vessel was raised to 7O 0 C over the next 25 minutes, at which time the pH was 3.9.
  • the solution temperature was held at 7O 0 C for 20 minutes, during which time the solution color changed from orange brown to a clear dark yellow.
  • the pH was 3.6 at 7O 0 C.
  • the temperature was lowered to 25 0 C over the next 25 minutes, at which time the pH was 4.2 at 25 0 C.
  • Particle size analysis by dynamic light scattering indicated a cerium dioxide intensity weighted hydrodynamic diameter of 6 nm.
  • the dispersion was then diafiltered to a conductivity of 3 mS/cm and concentrated, by a factor of about 10, to a nominal 1 Molar in CeO 2 particles.
  • a transmission electron microscope was used to analyze the cerium dioxide particles.
  • a 9-microliter solution (0.26M) was dried onto a grid and imaged to produce the image shown in FIG. 1.
  • the particles show no signs of agglomeration, even in this dried-down state. In solution, the particles would be expected to show even less propensity to agglomerate.
  • the size frequency distribution of the cerium dioxide particles (plotted in FIG 1), determined by transmission electron micrography (TEM), yields a geometric diameter of about 2.6 nm. Additionally, the size distribution is substantially monomodal, i.e., only one maximum, and uniform, 19% COV, with most of the particles falling in the range 2 nm to 4 nm.
  • FIG. 2 shows an X-ray powder diffraction pattern 70 of a sample of the dried cerium dioxide nanoparticles, together with a reference spectrum 71 of cerium dioxide that was provided by the NIST (National Institute of Standards and Technology) library.
  • the line positions in the sample spectrum match those of the standard spectrum.
  • the two theta peak widths were very wide in the sample spectrum, which is consistent with a very small primary crystallite size and particle size.
  • the primary crystallite size was calculated to be 2.5 ⁇ 0.5 nm (95 % confidence of 5 replicas). Since the particle itself is the size of this crystallite, there is only one crystal per particle, therefore we refer to this composition as crystalline cerium dioxide to distinguish it from all previous art in which the nanoparticles are comprised of agglomerates of crystallites of various sizes.
  • Example 2 Precipitation of - 1.5 nm CeO 2 Nanoparticles. This precipitation follows Example 1, except that the stabilizer combination of EDTA and lactic acid in the ratio 20:80 and at a level of 76.4 gm EDTA disodium salt and 74.0 gm of 85% lactic acid is used instead of the MEEA stabilizer .
  • FIG. 3 A is a high magnification TEM indicating a grain size substantially smaller than 5 nm and estimated to be 1.1 +/- 0.3 nm.
  • FIG. 3B represents the electron diffraction pattern of a representative sample of the precipitation.
  • FIG. 1 is a high magnification TEM indicating a grain size substantially smaller than 5 nm and estimated to be 1.1 +/- 0.3 nm.
  • FIG. 3B represents the electron diffraction pattern of a representative sample of the precipitation.
  • 3 C contains Table I in which the intensities of the various diffractions rings ⁇ 311 ⁇ , ⁇ 220 ⁇ , ⁇ 200 ⁇ and ⁇ 111 ⁇ are analyzed within the framework of: cubic CeO 2 , cubic and hexagonal Ce 2 ⁇ 3 and Ce(OFTb. Clearly the percent deviations of analyzed ring intensity with crystal habit are minimal for the cubic fluorite structure Of CeO 2 , thus establishing the existence of this polymorph down to this grain diameter.
  • Particle size-frequency analysis by transmission electron micrography revealed a mean particle size of 2.2nm, with size frequency distribution having a coefficient of variation, COV, (one standard deviation divided by the mean diameter) of 23%. The calculated yield was 62.9%.
  • Example 4 Copper-Containing CeO 2 Nanoparticles Ce o s>Cu o iO 195
  • the conditions of example 3 were repeated, except that the cerium nitrate solution contained 108.0 grams of cerium nitrate hexahydrate, and 6.42 grams of Ce(NOs)32.5 H 2 O. These metal salts were dissolved separately and then combined to form a 250 ml solution. The reaction proceeded as described in Example 3 except that the hydrogen peroxide was added over a period of 40 seconds after the cerium and ammonia had been added.
  • Particle size-frequency analysis by transmission electron micrography revealed a mean particle size of 2.5 nm, with size frequency distribution having a coefficient of variation, COV, (one standard deviation divided by the mean diameter) of 25%. Note the absence of a bi-modal distribution; a secondary peak would be an indication that the Cu was not incorporated into the CeO 2 lattice but instead existed as a separate Cu 2 ⁇ 3 population.
  • Example 5 Iron-Containing CeO 2 Nanoparticles Ce 09Fe 0 iO 1 95 (CeO-255)
  • Example 6 The conditions of Example 4 were repeated, except that the metal salts solution contained 108.0 grams of cerium nitrate hexahydrate, and 11.16 grams of Fe(NOs)39 H 2 O. These metal salts were dissolved separately and then combined to form a 250 ml solution. The reaction proceeded as described in Example 4. ATEM of the precipitated particles (FIG 6A) and particle size-frequency analysis by transmission electron micrography (FIG. 6B) revealed a mean particle size of 2.2 +/-0.7 nm, with size frequency distribution having a coefficient of variation, COV, (one standard deviation divided by the mean diameter) of 32%. The calculated yield was 55.1%. [00191] Example 6. Zirconium-Containing CeO 2 Nanoparticles Ce O gZr 0 I sO 2 (CeO)
  • Example 4 The conditions of Example 4 were repeated except that the metal salts solution contained 101.89 grams of cerium nitrate hexahydrate, and 9.57 grams OfZrO(NOs) 2 O H 2 O. These metal salts were dissolved separately and then combined to form a 250 ml solution.
  • the reaction proceeded as described in Example 4, except that the temperature of the reaction was carried out at 85 ° C.
  • Particle size-frequency analysis by transmission electron micrography revealed a mean particle size of 2.4 +/- 0.7 nm, with size frequency distribution having a coefficient of variation, COV, (one standard deviation divided by the mean diameter) of 29%.
  • Example 4 The conditions of Example 4 were repeated, except that the metal salts solution contained 84.0 grams of cerium nitrate hexahydrate, 11.16 grams of Fe(NOs)39 H 2 O and 12.76 grams of ZrO(NOs) 2 6 H 2 O. These metal salts were dissolved separately and then combined to form a 250 ml solution. The reaction proceeded as described in Example 4, except that the temperature of the reaction was carried out at 85 ° C, and the hydrogen peroxide solution (50%) was elevated to 20.4 gm and added over a period often minutes. Particle TEM (FIG 8A) and particle size-frequency analysis by transmission electron micrography (FIG.
  • 8C is an x-ray powder diffraction pattern of this sample (top curve) compared to the transition metal free CeO 2 .
  • the lack of a peak (denoted by an arrow) at 32 deg two theta means that there is no free ZrO 2 , i.e., it is all incorporated into the cerium lattice. Also, the lack of peaks at 50 and 52 degrees two theta indicate no separate population Of Fe 2 Os ( ie incorporation of Fe into the cerium lattice).
  • Example 7a The conditions of Example 7a were followed; however the amount of iron or zirconium was adjusted to give the nominal stoichiometries indicated, using the appropriate metal containing salt solution while the overall cerium nitrate hexahydrate was reduced to accommodate the increased concentration of the iron or zirconium transition metal.
  • FIG. 9 is a Field Emission Gun TEM lattice image of the particles made in Example 1. Two of the particles are circled for clarity. Note the small number of lattice planes that define a single crystal having a diameter of less than 5 nm.
  • Aqueous sols of various materials were heated for 30 minutes in a muffle furnace at 1000 ° C. These thoroughly dried samples were measured for OSC and the kinetics at which they reached their maximum OSC using thermogravimetric techniques, as described by Sarkas et al., "Nanocrystalline Mixed Metal Oxides-Novel Oxygen Storage Materials," Mat. Res. Soc. Symp. Proc. Vol. 788, L4.8.1 (2004). Typically, one observes a very fast initial reduction rate in nitrogen gas containing 5% hydrogen, followed by a second slower rate.
  • the accompanying TABLE 2 contains the Oxygen Storage Capacity (1 sigma reproducibility in parenthesis) and the fast (kl) and slow (k2) rate constants (1 standard deviation in parenthesis) for reduction of various lattice engineered ceria nanoparticles (all 2 nm except the Sigma Aldrich control) in a nitrogen gas at 700 ° C containing 5% H 2 . These values have been cross-checked against a second TGA instrument (average 2.6% difference), against gas flow differences (average 1 % deviation) and replicate sample preparation at 1000°C for 30 minutes (average 1.54% deviation). From the entries in TABLE 2, we see that the OSC of cerium dioxide particles does not appear to be size- dependent in the range of about 2 nm-20 ⁇ m.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Nanotechnology (AREA)
  • General Chemical & Material Sciences (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Combustion & Propulsion (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Analytical Chemistry (AREA)
  • Composite Materials (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Catalysts (AREA)
  • Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
  • Compounds Of Iron (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

La présente invention concerne un procédé de réalisation de nanoparticules de dioxyde de cérium contenant au moins un métal de transition (M), au moyen d'une suspension de nanoparticules d'hydroxyde de cérium. Ces nanoparticules sont préparées par cisaillement mécanique d'un mélange aqueux contenant un oxydant en une quantité efficace pour permettre l'oxydation d'ion céreux en ions cériques. Ceci forme un flux de produit qui contient des nanoparticules de dioxyde de cérium contenant un métal de transition, Cel-xMxO2, « x » ayant une valeur d'environ 0,3 à environ 0,8. Les nanoparticules ainsi obtenues possèdent une structure de fluorite cubique, un diamètre hydrodynamique moyen situé dans la plage d'environ 1 nm à environ 10 nm, et un diamètre géométrique inférieur à environ 4 nm. Les nanoparticules de dioxyde de cérium cristallines contenant un métal de transition peuvent être utilisées pour préparer une dispersion des particules dans un milieu non polaire.
PCT/US2008/087133 2006-09-05 2008-12-17 Additif pour carburant contenant des nanoparticules de dioxyde de cérium modifié en treillage WO2010071641A1 (fr)

Priority Applications (15)

Application Number Priority Date Filing Date Title
JP2011542092A JP5438772B2 (ja) 2008-12-17 2008-12-17 燃料添加剤含有格子操作二酸化セリウムナノ粒子
US13/140,648 US10435639B2 (en) 2006-09-05 2008-12-17 Fuel additive containing lattice engineered cerium dioxide nanoparticles
EP08879024.1A EP2379221A4 (fr) 2008-12-17 2008-12-17 Additif pour carburant contenant des nanoparticules de dioxyde de cérium modifié en treillage
RU2011129305/04A RU2487753C2 (ru) 2008-12-17 2008-12-17 Топливная добавка, содержащая наночастицы диоксида церия с измененной структурой
MX2011006461A MX2011006461A (es) 2008-12-17 2008-12-17 Aditivos de combustible que contienen nanopartículas de dióxido de cerio con diseño de red.
PCT/US2008/087133 WO2010071641A1 (fr) 2008-12-17 2008-12-17 Additif pour carburant contenant des nanoparticules de dioxyde de cérium modifié en treillage
CA2747547A CA2747547C (fr) 2008-12-17 2008-12-17 Additif pour carburant contenant des nanoparticules de dioxyde de cerium modifie en treillage
CN2008801326631A CN102281945A (zh) 2008-12-17 2008-12-17 包含晶格经改造的二氧化铈纳米颗粒的燃料添加剂
BRPI0823310-1A BRPI0823310B1 (pt) 2008-12-17 2008-12-17 Processo para fazer nanopartículas de dióxido de cério cristalino projetadas de forma reticulada contendo pelo menos um metal de transição (m)
KR1020117016496A KR101605465B1 (ko) 2008-12-17 2008-12-17 격자 엔지니어링된 이산화세륨 나노입자를 포함하는 연료 첨가제
AU2008365234A AU2008365234B2 (en) 2008-12-17 2008-12-17 Fuel additive containing lattice engineered cerium dioxide nanoparticles
US12/549,776 US8679344B2 (en) 2008-12-17 2009-08-28 Process for solvent shifting a nanoparticle dispersion
US12/779,602 US8883865B2 (en) 2006-09-05 2010-05-13 Cerium-containing nanoparticles
US14/537,161 US9340738B2 (en) 2006-09-05 2014-11-10 Method of making cerium oxide nanoparticles
US14/537,993 US9303223B2 (en) 2006-09-05 2014-11-11 Method of making cerium oxide nanoparticles

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2008/087133 WO2010071641A1 (fr) 2008-12-17 2008-12-17 Additif pour carburant contenant des nanoparticules de dioxyde de cérium modifié en treillage

Related Child Applications (3)

Application Number Title Priority Date Filing Date
PCT/US2007/077545 Continuation-In-Part WO2008030815A2 (fr) 2006-09-05 2007-09-04 Procédé de préparation de nanoparticules de dioxyde de cérium
US12/549,776 Continuation-In-Part US8679344B2 (en) 2008-12-17 2009-08-28 Process for solvent shifting a nanoparticle dispersion
US12/779,602 Continuation-In-Part US8883865B2 (en) 2006-09-05 2010-05-13 Cerium-containing nanoparticles

Publications (1)

Publication Number Publication Date
WO2010071641A1 true WO2010071641A1 (fr) 2010-06-24

Family

ID=42269082

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2008/087133 WO2010071641A1 (fr) 2006-09-05 2008-12-17 Additif pour carburant contenant des nanoparticules de dioxyde de cérium modifié en treillage

Country Status (10)

Country Link
EP (1) EP2379221A4 (fr)
JP (1) JP5438772B2 (fr)
KR (1) KR101605465B1 (fr)
CN (1) CN102281945A (fr)
AU (1) AU2008365234B2 (fr)
BR (1) BRPI0823310B1 (fr)
CA (1) CA2747547C (fr)
MX (1) MX2011006461A (fr)
RU (1) RU2487753C2 (fr)
WO (1) WO2010071641A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120117863A1 (en) * 2010-11-12 2012-05-17 Cerion Technology Inc. Cerium containing nanoparticles prepared in non-polar solvent
CN102559138A (zh) * 2010-12-23 2012-07-11 北京有色金属研究总院 一种掺杂氟离子和金属离子的氧化铈基纳米紫外屏蔽材料及其制备方法
JP2014189433A (ja) * 2013-03-27 2014-10-06 Nagoya Institute Of Technology セリウムとジルコニウムを含む金属酸化物とその製造方法
JP2015523301A (ja) * 2012-05-25 2015-08-13 セリオン エンタープライジズ リミテッド ライアビリティ カンパニー 酸化鉄ナノ粒子分散液及び煤煙燃焼のための燃料添加剤
US9283548B2 (en) 2013-11-19 2016-03-15 Toyota Motor Engineering & Manufacturing North America, Inc. Ceria-supported metal catalysts for the selective reduction of NOx
EP3184206A1 (fr) 2015-12-23 2017-06-28 Solvay SA Dispersions de métaux et/ou de composés métalliques
WO2019008374A1 (fr) * 2017-07-05 2019-01-10 Nanoco Technologies Ltd Architectures de points quantiques pour applications de filtre coloré
EP4092098A1 (fr) 2021-05-20 2022-11-23 Indian Oil Corporation Limited Composition additive servant d'améliorant de combustion pour combustibles liquides et gazeux

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101990070B1 (ko) * 2012-06-13 2019-06-17 세리온, 엘엘씨 산화 스트레스 치료용 나노세리아
KR20150067253A (ko) * 2012-10-08 2015-06-17 가부시키가이샤 산도쿠 복합 산화물의 제조 방법 및 복합 산화물 촉매
US10201797B2 (en) * 2012-11-27 2019-02-12 Laminar Co., Ltd. Reaction device for mixing and manufacturing method using the reaction device
JP6042783B2 (ja) * 2013-10-10 2016-12-14 トヨタ自動車株式会社 排ガス浄化用助触媒の製造方法
CN103484174B (zh) * 2013-10-15 2015-08-12 仁寿县驰骋油业有限公司 一种基于国标柴油的新型清洁柴油
JP2015160801A (ja) * 2014-02-27 2015-09-07 ラミナ カンパニー リミテッド 連続式反応器を用いた酸化金属の製造方法
EP3194096B1 (fr) * 2014-09-18 2020-09-09 Oerlikon Metco (US) Inc. Utilisation d'une charge d'alimentation pré-formulée en forme de poudre pour la projection thermique de suspension
US9969621B2 (en) * 2016-05-04 2018-05-15 Saudi Arabian Oil Company Methods for processing fumed metallic oxides
JP6780847B2 (ja) * 2016-09-01 2020-11-04 国立研究開発法人日本原子力研究開発機構 ヨウ化水素分解触媒及び水素製造方法
CN106930829B (zh) * 2017-03-06 2019-03-05 桂林航天工业学院 生物乙醇动力系统及其控制方法
CN107552059B (zh) * 2017-10-12 2020-05-12 浙江树人学院 一种铁掺杂铈基固溶体烟气脱硝催化剂的制备方法
GB2607851A (en) * 2018-06-15 2022-12-21 Seren Tech Limited Rare earth metal oxide preparation
GB201904694D0 (en) * 2019-04-03 2019-05-15 Johnson Matthey Plc Ceria-containingmixed oxides for oxygen storage
KR102372139B1 (ko) * 2019-05-09 2022-03-08 단국대학교 천안캠퍼스 산학협력단 산화물 나노입자의 전자밴드 엔지니어링을 통한 광학적 물성 제어
CN114901594A (zh) * 2019-12-26 2022-08-12 东丽株式会社 氧化铈的纳米粒子、分散体、氧化剂、抗氧化剂及氧化铈的纳米粒子的制造方法
WO2023167287A1 (fr) * 2022-03-03 2023-09-07 積水化学工業株式会社 Réducteur, et procédé de fabrication de gaz
CN116099354A (zh) * 2023-02-10 2023-05-12 昆明理工大学 一种球形氧化铈催化剂在低温催化水解有机污染物中的应用

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050066571A1 (en) * 2001-11-06 2005-03-31 Gareth Wakefield Cerium oxide nanoparticles
US20050165139A1 (en) * 2002-06-17 2005-07-28 Sanyo Chemical Industries, Ltd Resin particle and method for prepartion thereof
US20050227864A1 (en) * 2002-02-19 2005-10-13 Tal Materials Mixed-metal oxide particles by liquid feed flame spray pyrolysis of oxide precursors in oxygenated solvents
US20070224092A1 (en) * 2006-03-24 2007-09-27 Ngk Insulators, Ltd. Catalytic converter and a method for producing the catalytic converter

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5945925A (ja) * 1982-06-11 1984-03-15 ロ−ヌ−プ−ラン・スペシアリテ・シミ−ク コロイド状酸化セリウム分散液の製造方法
FR2741281B1 (fr) * 1995-11-22 1998-02-13 Rhone Poulenc Chimie Sol organique comportant au moins un compose oxygene de terre(s) rare(s), procede de synthese du dit sol et utilisation du dit sol pour la catalyse
US6133194A (en) * 1997-04-21 2000-10-17 Rhodia Rare Earths Inc. Cerium oxides, zirconium oxides, Ce/Zr mixed oxides and Ce/Zr solid solutions having improved thermal stability and oxygen storage capacity
FR2789601B1 (fr) * 1999-02-17 2001-05-11 Rhodia Chimie Sa Sol organique et compose solide a base d'oxyde de cerium et d'un compose amphiphile et procedes de preparation
DK1299508T3 (da) * 2000-06-29 2005-05-23 Neuftec Ltd Brændstofadditiv
US7141227B2 (en) * 2001-05-07 2006-11-28 The Trustees Of Columbia University In The City Of New York Apparatus and method for preparing cerium oxide nanoparticles
US7025943B2 (en) * 2002-05-15 2006-04-11 The Curators Of The University Of Missouri Method for preparation of nanometer cerium-based oxide particles
RU2252913C1 (ru) * 2003-10-13 2005-05-27 Институт Катализа Им. Г.К. Борескова Сибирского Отделения Российской Академии Наук Способ получения синтез-газа
WO2006046145A2 (fr) * 2004-10-25 2006-05-04 Philip Morris Products S.A. Catalyseur or-cerium permettant l'oxydation de monoxyde de carbone
FR2884732B1 (fr) * 2005-04-20 2007-08-24 Rhodia Chimie Sa Dispersion colloidale d'un compose de cerium et d'un autre element choisi parmi le zirconium, les terres rares, le titane et l'etain, solide dispersible a base de ce compose et procedes de preparation
FR2905371B1 (fr) * 2006-08-31 2010-11-05 Rhodia Recherches & Tech Composition a reductibilite elevee a base d'un oxyde de cerium nanometrique sur un support, procede de preparation et utilisation comme catalyseur
CA2662769A1 (fr) * 2006-09-05 2008-03-13 Cerion Technology, Inc. Procede de conditionnement d'un moteur a combustion interne
JP5099316B2 (ja) * 2007-04-27 2012-12-19 株式会社豊田中央研究所 セリア−ジルコニア複合酸化物及びその製造方法
CN101113010A (zh) * 2007-07-04 2008-01-30 北京化工大学 微波辅助制备氧化铈纳米粒子的方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050066571A1 (en) * 2001-11-06 2005-03-31 Gareth Wakefield Cerium oxide nanoparticles
US20050227864A1 (en) * 2002-02-19 2005-10-13 Tal Materials Mixed-metal oxide particles by liquid feed flame spray pyrolysis of oxide precursors in oxygenated solvents
US20050165139A1 (en) * 2002-06-17 2005-07-28 Sanyo Chemical Industries, Ltd Resin particle and method for prepartion thereof
US20070224092A1 (en) * 2006-03-24 2007-09-27 Ngk Insulators, Ltd. Catalytic converter and a method for producing the catalytic converter

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
REDDY ET AL.: "Surfactant-Controlled and Microwave-Assisted Synthesis of Highly Active CexZr1-xO2 Nano- Oxides for CO Oxidation", SPRINGER SCIENCE+BUSINESS MEDIA, LLC, 2 August 2008 (2008-08-02), pages 125 - 133, XP019640292 *
See also references of EP2379221A4 *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120117863A1 (en) * 2010-11-12 2012-05-17 Cerion Technology Inc. Cerium containing nanoparticles prepared in non-polar solvent
US8980202B2 (en) * 2010-11-12 2015-03-17 Peter Jerome COWDERY-CORVAN Cerium containing nanoparticles prepared in non-polar solvent
CN102559138A (zh) * 2010-12-23 2012-07-11 北京有色金属研究总院 一种掺杂氟离子和金属离子的氧化铈基纳米紫外屏蔽材料及其制备方法
CN102559138B (zh) * 2010-12-23 2014-01-08 有研稀土新材料股份有限公司 一种掺杂氟离子和金属离子的氧化铈基纳米紫外屏蔽材料及其制备方法
JP2015523301A (ja) * 2012-05-25 2015-08-13 セリオン エンタープライジズ リミテッド ライアビリティ カンパニー 酸化鉄ナノ粒子分散液及び煤煙燃焼のための燃料添加剤
JP2014189433A (ja) * 2013-03-27 2014-10-06 Nagoya Institute Of Technology セリウムとジルコニウムを含む金属酸化物とその製造方法
US9283548B2 (en) 2013-11-19 2016-03-15 Toyota Motor Engineering & Manufacturing North America, Inc. Ceria-supported metal catalysts for the selective reduction of NOx
US9815044B2 (en) 2013-11-19 2017-11-14 Toyota Motor Engineering & Manufacturing North America, Inc. Ceria-supported metal catalysts for the selective reduction of NOX
EP3184206A1 (fr) 2015-12-23 2017-06-28 Solvay SA Dispersions de métaux et/ou de composés métalliques
WO2019008374A1 (fr) * 2017-07-05 2019-01-10 Nanoco Technologies Ltd Architectures de points quantiques pour applications de filtre coloré
US10768485B2 (en) 2017-07-05 2020-09-08 Nanoco Technologies Ltd. Quantum dot architectures for color filter applications
EP4056665A1 (fr) * 2017-07-05 2022-09-14 Nanoco Technologies, Ltd. Architectures de points quantiques pour applications de filtre coloré
EP4092098A1 (fr) 2021-05-20 2022-11-23 Indian Oil Corporation Limited Composition additive servant d'améliorant de combustion pour combustibles liquides et gazeux
US11603503B2 (en) 2021-05-20 2023-03-14 Indian Oil Corporation Limited Additive composition as a combustion improver for liquid and gaseous fuels

Also Published As

Publication number Publication date
RU2487753C2 (ru) 2013-07-20
JP5438772B2 (ja) 2014-03-12
KR20110106884A (ko) 2011-09-29
CA2747547C (fr) 2017-10-17
CN102281945A (zh) 2011-12-14
BRPI0823310B1 (pt) 2018-02-14
BRPI0823310A2 (pt) 2015-06-23
JP2012512127A (ja) 2012-05-31
MX2011006461A (es) 2011-11-18
AU2008365234B2 (en) 2015-05-07
KR101605465B1 (ko) 2016-03-22
BRPI0823310A8 (pt) 2015-11-24
RU2011129305A (ru) 2013-01-27
EP2379221A4 (fr) 2013-05-15
CA2747547A1 (fr) 2010-06-24
EP2379221A1 (fr) 2011-10-26
AU2008365234A1 (en) 2011-07-07

Similar Documents

Publication Publication Date Title
AU2008365234B2 (en) Fuel additive containing lattice engineered cerium dioxide nanoparticles
US10435639B2 (en) Fuel additive containing lattice engineered cerium dioxide nanoparticles
EP2064153B1 (fr) Procédé de préparation de nanoparticules de dioxyde de cérium
JP6510403B2 (ja) 酸化鉄ナノ粒子分散液及び煤煙燃焼のための燃料添加剤
US20100088949A1 (en) Method of conditioning an internal combustion engine
JP5870081B2 (ja) 燃料添加剤含有格子操作二酸化セリウムナノ粒子
WO2008127395A2 (fr) Agent lubrifiant céramique à haute température

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 200880132663.1

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08879024

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2008365234

Country of ref document: AU

Ref document number: MX/A/2011/006461

Country of ref document: MX

ENP Entry into the national phase

Ref document number: 2011542092

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2747547

Country of ref document: CA

ENP Entry into the national phase

Ref document number: 2008365234

Country of ref document: AU

Date of ref document: 20081217

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 20117016496

Country of ref document: KR

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 5450/DELNP/2011

Country of ref document: IN

Ref document number: 2008879024

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 2011129305

Country of ref document: RU

WWE Wipo information: entry into national phase

Ref document number: 13140648

Country of ref document: US

ENP Entry into the national phase

Ref document number: PI0823310

Country of ref document: BR

Kind code of ref document: A2

Effective date: 20110617