Classifications

• • 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
  • B01J37/34—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation
  • B01J37/341—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of electric or magnetic fields, wave energy or particle radiation
  • B01J37/344—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of electric or magnetic fields, wave energy or particle radiation of electromagnetic wave energy
  • B01J37/345—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of electric or magnetic fields, wave energy or particle radiation of electromagnetic wave energy of ultraviolet wave energy
• • 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
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
  • B01J23/44—Palladium
• • 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
  • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
  • B01J23/48—Silver or gold
  • B01J23/52—Gold
• • 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
  • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
  • B01J31/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
  • B01J31/1691—Coordination polymers, e.g. metal-organic frameworks [MOF]
• • 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
  • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
  • B01J31/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
  • B01J31/18—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes containing nitrogen, phosphorus, arsenic or antimony as complexing atoms, e.g. in pyridine ligands, or in resonance therewith, e.g. in isocyanide ligands C=N-R or as complexed central atoms
  • B01J31/1805—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes containing nitrogen, phosphorus, arsenic or antimony as complexing atoms, e.g. in pyridine ligands, or in resonance therewith, e.g. in isocyanide ligands C=N-R or as complexed central atoms the ligands containing nitrogen
• • 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
  • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
  • B01J31/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
  • B01J31/22—Organic complexes
  • B01J31/2204—Organic complexes the ligands containing oxygen or sulfur as complexing atoms
• • 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
  • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
  • B01J31/16—Catalysts comprising hydrides, coordination complexes or organic compounds containing coordination complexes
  • B01J31/22—Organic complexes
  • B01J31/2204—Organic complexes the ligands containing oxygen or sulfur as complexing atoms
  • B01J31/2208—Oxygen, e.g. acetylacetonates
  • B01J31/2226—Anionic ligands, i.e. the overall ligand carries at least one formal negative charge
  • B01J31/223—At least two oxygen atoms present in one at least bidentate or bridging ligand
  • B01J31/2239—Bridging ligands, e.g. OAc in Cr2(OAc)4, Pt4(OAc)8 or dicarboxylate ligands
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
  • C07C29/15—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively
  • C07C29/151—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively with hydrogen or hydrogen-containing gases
  • C07C29/153—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively with hydrogen or hydrogen-containing gases characterised by the catalyst used
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
  • C07C29/15—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively
  • C07C29/151—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively with hydrogen or hydrogen-containing gases
  • C07C29/153—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively with hydrogen or hydrogen-containing gases characterised by the catalyst used
  • C07C29/154—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by reduction of oxides of carbon exclusively with hydrogen or hydrogen-containing gases characterised by the catalyst used containing copper, silver, gold, or compounds thereof
• • 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
  • B01J2231/00—Catalytic reactions performed with catalysts classified in B01J31/00
  • B01J2231/60—Reduction reactions, e.g. hydrogenation
  • B01J2231/64—Reductions in general of organic substrates, e.g. hydride reductions or hydrogenations
  • B01J2231/641—Hydrogenation of organic substrates, i.e. H2 or H-transfer hydrogenations, e.g. Fischer-Tropsch processes
  • B01J2231/643—Hydrogenation of organic substrates, i.e. H2 or H-transfer hydrogenations, e.g. Fischer-Tropsch processes of R2C=O or R2C=NR (R= C, H)
• • 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
  • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
  • B01J2531/10—Complexes comprising metals of Group I (IA or IB) as the central metal
  • B01J2531/16—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
  • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
  • B01J2531/20—Complexes comprising metals of Group II (IIA or IIB) as the central metal
  • B01J2531/26—Zinc
• • 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
  • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
  • B01J2531/30—Complexes comprising metals of Group III (IIIA or IIIB) as the central metal
  • B01J2531/31—Aluminium
• • 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
  • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
  • B01J2531/30—Complexes comprising metals of Group III (IIIA or IIIB) as the central metal
  • B01J2531/33—Indium
• • 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
  • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
  • B01J2531/40—Complexes comprising metals of Group IV (IVA or IVB) as the central metal
  • B01J2531/42—Tin
• • 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
  • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
  • B01J2531/40—Complexes comprising metals of Group IV (IVA or IVB) as the central metal
  • B01J2531/46—Titanium
• • 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
  • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
  • B01J2531/80—Complexes comprising metals of Group VIII as the central metal
  • B01J2531/84—Metals of the iron group
  • B01J2531/842—Iron
• • 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
  • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
  • B01J35/61—Surface area
  • B01J35/617—500-1000 m2/g
• • 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
  • B01J37/0238—Impregnation, coating or precipitation via the gaseous phase-sublimation
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Definitions

• the invention relates to a process for the preparation of a catalyst, to a catalyst obtainable by the process, and to the use thereof.
• Cu / ZnO systems which are usually supplemented by Al 2 O 3 , are used as catalysts. These catalysts are produced on a large scale by precipitation reactions. Copper and zinc act as catalytically active substances, while the aluminum oxide is attributed a thermostabilizing effect as a structural promoter. The atomic ratios between copper and zinc can vary, but the copper is generally in excess. - -
• Such catalysts are known, for example, from DE-A-2 056 612 and from US Pat. No. 4,279,781.
• a corresponding catalyst for the synthesis of methanol is also known from EP-AO 125 689.
• This catalyst is characterized in that the proportion of pores having a diameter in the range of 20 to 75 ⁇ is at least 20% and the proportion of pores having a diameter of more than 75 ⁇ is at most 80%.
• the Cu / Zn atomic ratio is between 2.8 and 3.8, preferably between 2.8 and 3.2, and the proportion of Al 2 O 3 is 8 to 12 wt .-%.
• a similar catalyst for the synthesis of methanol is known from DE-A-44 16 425. It has an atomic ratio Cu / Zn of 2: 1 and generally consists of 50 to 75 wt .-% of CuO, 15 to 35 wt .-% of ZnO and also contains 5 to 20 wt .-% Al 2 O. 3 .
• EP-AO 152 809 discloses a catalyst for the synthesis of methanol mixtures and alcohol mixtures containing higher alcohols, which in the form of an oxidic precursor comprises (a) copper oxide and zinc oxide, (b) aluminum oxide as thermostabilizing substance and (c) at least one Alkali metal carbonate or alkali metal oxide, wherein the oxide precursor has a proportion of pores with a diameter between 15 and 7.5 nm from 20 to 70% of the total volume, the alkali content is 13 to 130 x 10 -6 per gram of the oxide precursor and the Alumina component has been obtained from a colloidally dispersed aluminum hydroxide (aluminum hydroxide sol or gel).
• the Cu / ZnO system is the basis of industrial methanol synthesis and an important component of fuel cell technology (reformer). It is considered a prototype for the exploration of synergistic metal / carrier interactions in heterogeneous catalysis [PL Hansen, JB Wagner, S. Helveg, JR Rostrup-Nielsen, BS Clausen, H. Tops0e, M. Science 2002, 295, 2053-2055 ].
• TEM transmission electron microscopy
• Zeolites and zeolite-like structures such as mordenite, VPI-5, or cloverites, as well as periodic mesoporous silicate minerals (PMS) such as MCM-41, MCM-48, or SBA-15, have, due to their very high specific surface areas and lower
• PMS periodic mesoporous silicate minerals
• MCM-41, MCM-48, or SBA-15 periodic mesoporous silicate minerals
• the object of the invention was to provide a process for the preparation of catalysts, in particular for the synthesis of methanol, with which catalysts having a very high activity can be obtained.
• the invention provides a process for the preparation of a catalyst with a porous support and at least one active metal, wherein a porous support is provided which has a BET specific surface area of at least 500 m 2 / g, the porous support being transparent to an activation radiation,
• At least one Aktivmetallierecursor is applied to the porous support, which comprises at least one active metal and at least one cleavable by the activation radiation group which is bound via a ligator atom to the active metal atom, which is selected from oxygen, sulfur, nitrogen, phosphorus and carbon, so that Adduct is produced which comprises the porous support and the at least one active metal precursor; and
• the adduct is exposed to the activating radiation, releasing the active metal.
• the active metal is released from the active metal precursor by exposure to an activation radiation, i. under extremely mild conditions.
• the release is preferably carried out at room temperature or at temperatures below room temperature.
• the active metal can be deposited in the form of very small particles on the surface of the porous support. Due to the low thermal load during the release practically no growth of the active metal particles takes place and gives a very high specific surface of the active metal and thus a very high activity of the catalyst prepared by the process according to the invention.
• the process according to the invention is carried out in such a way that initially a porous support with a very high specific surface area of at least 500 m 2 / g is provided. - -
• porous support is selected to be transparent to the activation radiation.
• a transparent carrier is understood as meaning a carrier which has such a high permeability to the activating radiation that internal regions of the carrier, for example a grain of the carrier material, can be reached by the activating radiation to a sufficient intensity to effect conversion of the active metal precursor to be able to effect. It is therefore not necessary that the carrier for the activation radiation is completely or at least almost completely transparent. It is only necessary that the activation radiation is absorbed by the carrier material only to the extent that a release of the active metal can take place in the entire volume of the carrier. The material of the carrier is therefore selected depending on the activation radiation used.
• a transparent carrier is preferably understood to mean a carrier which, in the case of a layer of 1 mm, causes a weakening of the intensity of the activation radiation by preferably at most 70%, in particular at most 50%.
• the activation radiation is again selected depending on the active metal precursor used.
• the activation radiation is selected so that it can cause a release of the active metal from the active metal precursor.
• a suitable activation radiation can be determined, for example, by means of an absorption spectrum.
• the active metal precursor is then applied to the porous support.
• the active metal precursor is applied to both the outer and the inner surface of the porous support.
• a porous support having a very high specific surface area is used, the majority of the surface being provided within the pores of the support.
• the term “applied” also encompasses the process by which the active metal precursor is introduced into the pores in the interior of the support. Any suitable process can be used for the application of the active metal precursor
• the active metal precursor can be applied dissolved in an inert solvent, for example
• the inert solvents used are usually nonpolar aliphatic or aromatic hydrocarbons, since the active metal precursors usually also have very non-polar properties
• When loading the porous support with an active metal precursor dissolved in an inert solvent charges in the range of preferably 1 At loading from the gas phase, significantly higher loadings can be achieved, with loadings of more than 10% by weight, preferably more than 20% by weight, in particular more than 30% by weight. % Active achieved tall, based on the porous support.
• the active metal precursor is applied from the gas phase.
• the solvent is preferably first evaporated, optionally at reduced pressure or elevated temperature.
• the active metal precursor generally does not react with the porous support during application, but is adsorbed by relatively weak interactions on the surface or in the pores of the porous support.
• the porous carrier and the active metal precursor thus form an adduct from which the active metal precursor can be largely removed by diffusion again, for example by heating.
• silicate compounds are used as porous supports, such as layer silicates or zeolites, the binding of the active metal precursor to the porous support can be effected, for example, via hydroxyl groups on the support.
• adduct formation may be based on van der Waals interactions.
• the adduct of active metal precursor and porous support is then exposed to the activation radiation, if appropriate after removal of traces of solvent.
• the duration and intensity of the exposure is chosen depending on the system of porous support, active metal precursor and activating radiation used. The appropriate parameters can be readily determined by appropriate preliminary tests.
• the exposure may be performed at reduced pressure, for example, to remove by-products released from the active metal precursor.
• an active metal is understood as meaning a metal which has a catalytic effect on the reaction to be catalyzed in the finished catalyst.
• this is copper, which is predominantly metal in the active form of the catalyst.
• an active metal precursor is accordingly understood a compound from which the active metal can be released.
• the ligator atom is thereby Choose from oxygen, sulfur, nitrogen, phosphorus and carbon.
• the active metal preferably carries organic groups, ie groups which, in addition to the ligator atoms 0, S, N, C and P, have at least one carbon atom. These organic groups preferably have 1 to 24 carbon atoms, in particular 1 to 6 carbon atoms.
• the groups attached to the active metal are preferably selected so that they absorb the activation radiation.
• heteroatoms or heteroatomic groups can be bound to the carbon skeleton, which can coordinate as Lewis bases to the active metal and thereby stabilize the active metal precursor.
• Suitable organic groups are, for example, alkoxides or amino-functionalized alkoxides.
• the active metal precursors are selected so that they can penetrate into the pores of the porous support.
• the diameter of the active metal precursor in at least two dimensions is preferably at most 90% of the pore diameter of the porous support, more preferably at most 80% and most preferably at most 50% of the pore diameter.
• the diameter of the active metal precursor in all three spatial dimensions is at most 90%, in particular at most 80%, preferably at most 50% of the pore diameter of the porous support.
• the active metal precursors preferably have a diameter which is less than the pore diameter of the porous support.
• the active metal precursor preferably comprises at least two groups which are bonded to the active metal atom via a ligator atom. _ -
• the groups are bonded in the active metal precursor via carbon as a ligator atom to the active metal.
• a “porous carrier” is preferably understood as meaning a carrier which has cavities which are open at least at one side, and the opening of these cavities preferably has a diameter of approximately 0.5 to 20 nm, preferably approximately 0.7, at least along an extension direction up to 10 nm, more preferably about 0.7 to 5 nm and most preferably about 0.7 to 2 nm, the term “cavity” is to be interpreted broadly such a cavity may, for example, an approximately spherical cavity or a channel with a However, the cavity can also be formed between two layers, for example in layered silicates, but the cavity has a comparatively small opening, so that the active metal precursor diffuses in a controlled manner into the cavity and there In the case of layered silicates, therefore, the above corresponds indicated diameters of about 0.7 to about 20 nm substantially the interlayer spacing. In spherical cavities, the porous support has pores of approximately circular circumference.
• the extent of the opening of the cavity can be determined, for example, by nitrogen adsorption measurements according to the BJH method (DIN 66134).
• the pore size can also be calculated, for example, from X-ray structural data coupled with the corresponding simulation programs.
• the porous support is characterized by a high specific surface area of at least 500 m 2 / g, preferably at least 600 - -
• the specific surface area is determined by nitrogen adsorption measurement by the BET method (DIN 66131).
• the specific surface can be determined according to the Langmuir method (DIN 66135).
• the porous supports preferably have a pore volume of more than 0.09 cm 3 / g, particularly preferably more than 0.15 cm 3 / g.
• the pore volume is preferably less than 1.5 cmVg.
• At least one promoter metal may furthermore be contained in the adduct of porous carrier and active metal precursor.
• a promoter metal is understood as meaning a metal which forms the promoter in the finished catalyst.
• the promoter is generally present in the catalyst in the form of an oxide.
• zinc and possibly aluminum can form the promoter metals.
• Further suitable promoter metals are, for example, tin, indium and titanium.
• the promoter metal is preferably present in the adduct not in the form of the metal but in oxidized form, for example as an oxide or as a metal complex. However, these promoters can also be in the form of metals in the finished catalyst. By means of such promoter metals, for example noble metal particles, that is to say the active metals, can be deliberately poisoned by alloying, in order for example to increase the selectivity of the catalyzed reaction.
• the promoter metal may be contained in the porous carrier or introduced as a separate compound in the adduct. The promoter metal or a suitable compound of the promoter metal can be introduced before the release of the active metal in the adduct, so be applied to the porous support. It is also - -
• the promoter metal is also applied in the form of a precursor, preferably in the form of an organometallic compound, on the porous support and the promoter metal or a suitable compound of the promoter metal, such as an oxide, released from the precursor.
• the release can be carried out, for example, as with the active metal precursor by exposure to an activation radiation.
• the promoter metal or the promoter metal compound as the active metal is deposited in nanodisperse form on the porous support.
• the precursor of the promoter metal therefore preferably comprises at least one promoter metal and at least one group which is bound to the promoter metal via a ligator atom.
• the bond can take place both via a ⁇ bond and via an n bond.
• the ligator atom like the active metal precursor, can be selected from oxygen, sulfur, nitrogen, phosphorus and carbon.
• the promoter metal carries organic groups, i. H. Groups which have at least one carbon atom in addition to the ligator atoms O, S, N, C and P. These organic groups preferably have 1 to 24 carbon atoms, in particular 1 to 6 carbon atoms.
• the promoter metal carries small ligands, such as trialkylphosphines, wherein the alkyl groups preferably each comprise 1 to 6 carbon atoms, and isonitriles, nitriles, cyclopentadienyl, alkenyl, or alkyl groups, preferably methyl groups.
• small ligands such as trialkylphosphines, wherein the alkyl groups preferably each comprise 1 to 6 carbon atoms, and isonitriles, nitriles, cyclopentadienyl, alkenyl, or alkyl groups, preferably methyl groups.
• the groups bound to the promoter metal preferably have between 1 and 24, particularly preferably 1 to 6, carbon atoms and, if appropriate, may also be bonded via a heteroatom. ne groups that can stabilize the precursor of the promoter metal as Lewis bases.
• the groups in the precursor of the promoter metal are selected from alkyl groups, alkenyl groups, aryl groups, a cyclopentadienyl radical and its derivatives, and a hydride group.
• certain organometallic compounds may advantageously be considered in the process according to the invention.
• Organometallic compounds are to be understood as meaning:
• Metal complexes in which, although there is no metal-carbon bond, but (coordinatively bound) ligands are contained which are organic in nature, ie belonging to the family of hydrocarbon compounds or derivatives thereof. "Organometallic" thus distinguishes from purely inorganic metal complexes that contain neither metal-carbon bonds nor organic ligands.
• the order in which the at least one active metal precursor and optionally the precursor of the at least one promoter metal is applied to the porous carrier is not subject to any restrictions per se.
• the carrier can first be loaded with the active metal precursor and then the precursor of the promoter metal applied before the active metal and optionally the promoter metal are deposited on the carrier by exposure to the activation radiation. But it is also possible to first apply the precursor of the promoter metal on the support and then the Aktivmetall remplicursor, _
• the active metal precursor can be applied to the porous support and to fix the active metal by irradiation with the activation radiation.
• the promoter metal precursor can then be applied to the porous support already coated with the active metal and fixed there.
• the fixation of the promoter metal or the promoter metal compound, such as an oxide of the promoter metal by exposure to the activation radiation or by other methods, eg. Example, by oxidation or reduction with a suitable gaseous oxidizing or reducing agent. It is also possible to apply the active metal precursor and the precursor of the promoter metal alternately several times on the support.
• the active metal precursor or the precursor of the promoter metal is first physisorbed or chemisorbed on the surfaces of the porous support, in particular on the surfaces of the cavities. By exposure to the activation radiation, the active metal from the active metal precursor or the promoter metal or a suitable compound of the promoter metal is then released from the promoter metal precursor and precipitated.
• the individual metal or metal oxide components of the catalyst are applied from the gas phase to the porous support.
• the active metal precursors and, if promoter metals are to be introduced into the adduct or the catalyst, the promoter metal precursors of the metals at 298 K preferably have a vapor pressure of at least 0.1 mbar.
• organometallic complexes are therefore used as active metal precursors and, if provided in the catalyst, as precursors of the promoter metals.
• the active metal precursor can be applied in solution and then the precursor of the promoter metal can be applied from the gas phase.
• the precursor of the promoter metal can be applied in solution.
• the precursor of the promoter metal can be applied in solution. Subsequently, at least the fixation of the active metal by irradiation with the activation radiation.
• the active metal precursor and, if appropriate, the precursor of the promoter metal are applied from the gas phase to the porous support, the stoichiometry of the catalyst produced can be controlled very precisely.
• the deposition can be set very accurately by the selected pressure or the selected temperature.
• the active metal is released from the active metal precursor by exposure to an activation radiation.
• the activation radiation used ie its wavelength, depends on the active metal precursor and on the material of the porous support.
• an activation radiation is used which provides a sufficient energy density, for example microwave radiation.
• ultrasound is also possible to use ultrasound as activation radiation.
• the activation radiation selected is ultraviolet radiation.
• the mercury vapor lamp spectrum is suitable, in particular radiation having a wavelength of 254 nm.
• the activation radiation is selected in a wavelength range from 10 -6 to ICT 8 m, preferably 10 -6 to 10 -7 m.
• carrier materials are used, on which the active metal and optionally the promoter is deposited.
• the carrier materials are characterized by a nanometer range adjustable, high porosity and thus extremely high specific surface area.
• the inventors start from the model idea that the cavities or pores act as dimensionally restricted reaction spaces, so that unwanted particle growth in the catalyst preparation is avoided.
• the cavity has a comparatively small opening, so that the active metal precursor can be diffused into the cavity and deposited there. Therefore, only a limited amount of the active metal is deposited in each cavity. On the walls of these reaction spaces or in the reaction spaces themselves, the active metal is therefore distributed in nanodisperse form after release.
• the maximum diameter of the particles does not exceed the pore diameter at least in one direction, which is about 2 nm using, for example, an MCM-41.
• the catalyst is heated to higher temperatures, for example, now no exchange between the different cavities, so that a growth of the catalytically active particles is largely suppressed and the nanodisperse distribution of the catalytically active centers is largely retained.
• the long-term stability of the catalysts under process conditions is favorably influenced thereby. Since the surface of the porous carrier materials is essentially formed by the pores of the carrier material, the active metal precursors and possibly the precursor of the promoter metals preferably absorb on the inner surface of these carrier materials and thus come into direct chemical proximity in a very controllable manner.
• MOF systems are used as porous supports. These systems include metal atoms that are three-dimensionally linked to a network via at least bidentate organic ligands and are suitable, for example, for hydrogen storage. These compounds are characterized by very high pore volumes of about 2-3 cmVg and up to 10 cm 3 / g and by very high specific surface areas of more than 1000 m 2 / g, particularly preferably more than 2000 m 2 / g. MOF systems form crystal-like structures that form large cavities. The inventors believe that the active metal, and optionally the promoter metal, or a suitable promoter metal compound form clusters of a few metal atoms incorporated in the reticular structure of the MOF system.
• the size of such a collection of metal atoms is then limited by the size of the single cavity. For example, if the MOF system consists of a three-dimensional accumulation of cube-shaped cavities, globular accumulations of metal atoms and possibly other compounds can be incorporated in these cavities.
• the MOF system is formed by a zinc carboxylate.
• These crystalline substances have extremely high specific surface areas of up to 4,500 m 2 / g or pore volumes of up to 0.69 cm 3 / cm 3 with simultaneously high thermal stability of up to 350 0 C for example, MOF-177.
• the zinc carboxylate is formed by MOF-5.
• MOF-5 is formed by zinc atoms, which are three-dimensionally cross-linked via terephthalic acid. MOF-5 is described, for example, in H. Li, M. Eddaoudi, M. O'Keeffe, OM Lughi, Nature (402) 1999, 276- - -
• the zinc contained in the zinc carboxylate can act as promoter metal.
• the inventive method makes it possible to apply several different active metals in a controlled manner in nanodisperse form on the porous support or to store it in its structure.
• the catalytically active metal component comprises several metals or metal compounds, for example metal oxides, these are in intensive contact since the individual constituents are present in each nanodisperse form.
• the special feature of the method according to the invention is that, in contrast to other known impregnation methods, the active metal precursors are exposed with an activation radiation to deposit and chemically fix the active metal in a reaction space delimited by the support in nanoscale dimensions.
• the active metals are mostly in the form of an oxide. Exceptions are very noble active metals, such as Pt and Pd, etc.
• the oxides are formed due to air oxidation after catalyst preparation. However, according to the state of the art, it is possible in an established manner to oxidize the metal mold only proportionally by means of special stabilization measures.
• the active metal is passivated by a thin oxide layer. After filling in the reactor, the catalyst can then be converted back into its active form by a mild and simple re-reduction. For this purpose, these oxide layers are reduced, for example, with hydrogen.
• the quality of the catalytic activity of the system and does not substantially alter its chemical composition and structural characteristics through repeated oxidation and reduction cycles; ie a corresponding catalyst regeneration to restore the original catalytic activity is possible in an advantageous manner.
• the active metal is preferably selected from the group consisting of Al, Zn, Sn, Bi, Cr, Ti, Zr, Hf, V, Mo, W, Re, Cu, Ag, Au, Ni, Pd, Pt, Co , Rh, Ir, Fe, Ru, and Os.
• the active metal may comprise only one metal from the above-mentioned group, for example copper or zinc. However, it is also possible that the active metal comprises several metals from the above-mentioned group, for example two or three metals.
• the metals may be present in reduced form as pure metal or as metal compound, in particular as metal oxide, on the porous support.
• the active metal in the transport form of the catalyst is usually present in at least partially oxidized form, so that the catalyst is also sufficiently stable in air.
• the promoter metal is selected from the group consisting of Al, Zn, Sn, rare earth metals, as well as alkali and alkaline earth metals.
• Suitable alkali and alkaline earth metals are e.g. Li, Na, K, Cs, Mg and Ba.
• the active metal and the promoter metal are chosen differently.
• the catalyst preferably comprises the system Cu / Zn / Al.
• the atomic number ratios of Cu / Zn / Al are in the typical range between 1: 3: 0.1 to 3: 1: 1.
• the copper by a suitable Aktivmetallmaschinecursor, the zinc, for example, via a suitable Promoter metal precursor or over the material of the porous support and the aluminum are also introduced via the material of the porous support or via a suitable promoter metal precursor.
• R * is an alkyl radical having 1 to 6 carbon atoms, an alkenyl radical having 2 to 6 carbon atoms, an aryl radical having 6 to 18 carbon atoms, and further the radicals R * may be the same or different
• p is an integer corresponding to the valence of the active metal
• o is an integer between 0 and the number of free coordination sites of the active metal atom
• L is a Lewis basic organic ligand which is oxygen, Nitrogen, phosphorus or carbon as the ligator atom.
• L and X may comprise only one kind of said ligands or residues. However, it is also possible to provide combinations of said groups.
• the promoter metal precursor is a compound of the formula MR n L n , where M is a promoter metal, R may have the same meaning as the group "X" in the active metal precursor, n is an integer which is the Valence of the promoter metal corresponds to, L is a Lewis basic organic ligand comprising oxygen, nitrogen, phosphorus or carbon as ligator atom, and m is an integer between 0 and the number of free coordination sites of the promoter metal atom. It also applies to the precursor for the promoter metal that only one kind of said group can be used for the radical R and the ligand L. However, it is also possible to combine different groups.
• ligands L which can be used are compounds of the formula OR 1 R “, NR 1 R 11 R '", PR 7 R 11 R “ 1 or CR' R 11 R” 1 , where the radicals R ', R “and R 1 "represent hydrogen or an alkyl group having 1 to 6 carbon atoms, wherein also two of these radicals can form a ring together with the heteroatom.
• the porous support may be made of any material per se, as long as the material has the required transparency for the activation radiation.
• the carrier should include the cavities described above, which have a relatively small aperture of the dimensions indicated above.
• the MOF systems already mentioned are suitable as porous support materials.
• the support be of an inorganic material _
• zeolites e.g., zeolites, PMS, layered silicates such as bentonites, clays or pillard clays, hydrotalcites, as well as heteropolyacids, e.g. of molybdenum and tungsten.
• periodic meso-porous silicate materials are used because they have very high specific surface areas and the pore structure can be precisely adjusted.
• Examples are MCM-41, MCM-48 or SBA-I5.
• Zeolites are again preferred those which have a large pore radius.
• Zeolites with a pore radius of> 0.7 nm are e.g. Mordenite, VPI-5 or Cloverite.
• MOF systems are used as porous support materials.
• the MOF systems are formed by a metal component which is three-dimensionally linked by an at least bidentate ligand, so that a crystal-like structure is obtained with periodically repeating structural units.
• Suitable metals or metal ions are the elements of group Ia, IIa, IIIa, IV - Villa and Ib - VIb of the Periodic Table of the Elements.
• at least bidentate ligands for example, substituted and unsubstituted, mono- or polynuclear aromatic dicarboxylic acids and substituted or unsubstituted, mono- or polynuclear, at least one heteroatom-containing aromatic dicarboxylic acids can be used.
• the metal component is particularly preferably selected from metals of the group Zn, Cu, Fe, Al, Sn, In, Ti, which are crosslinked in three dimensions by at least bidentate ligands ZR a -Z.
• Z denotes a carboxy group, a carbamide group, an amino group, a hydroxy group, a thio - -
• R a represents a phenylene group which may be substituted by alkyl groups having 1-6 carbon atoms, alkenyl groups having 2-6 C atoms, alkoxy groups having 1-6 carbon atoms and 1 to 3 oxygen atoms, halogen atoms or amino groups.
• R a can also comprise several phenyl nuclei and can be selected, for example, from the group of
• A is hydrogen, alkyl groups having 1-6 carbon atoms, alkenyl groups having 2-6 carbon atoms, alkoxy groups having 1-6 carbon atoms and 1 to 3 oxygen atoms, halogen atoms or amino groups, wherein A may be the same or different at each occurrence.
• the substituents A can also be arranged several times on the aromatic skeleton, i. the groups shown above may also carry a plurality of substituents A, for example 2, 3 or 4.
• R is a phenylene group
• X is a carboxy group
• A is hydrogen
• the preparation of the catalyst is carried out under extremely mild conditions. Thus, during the preparation of the catalyst - -
• a temperature of 200 0 C is not exceeded.
• the preparation is carried out at room temperature, and at reduced pressure.
• the active metal is thereby deposited in highly dispersed form, wherein the diameter of the particles produced from the active metal is generally in the range of about 0.5 to 10 nm, preferably 0.5 to 5 nm.
• a possibly present promoter can also be deposited in highly dispersed form, so that a very large contact area between active metal and promoter can be achieved. This leads to catalysts with very high activity.
• the invention therefore also provides a catalyst comprising a porous support having a specific surface area of at least 500 m 2 / g and at least one active metal or an active metal oxide, characterized in that the porous support is formed by a MOF system.
• the peculiarity of the catalyst according to the invention is that it comprises a MOF system as the porous support.
• This MOF system comprises metal atoms that are three-dimensionally linked to form a network via at least bidentate ligands.
• the network contains large cavities which can be filled with the active metal. Very high loadings are achieved, up to more than 40% by weight, based on the MOF system.
• the individual cavities in the MOF system form cells between which only a limited exchange of metal atoms is possible.
• the active metal is trapped in the MOF system in the form of small particles whose size is limited by the size of the cavity and which, therefore, show substantially no particle growth and provide a very high surface area of the active metal.
• the catalysts show a very high activity and a very high resistance even over long periods of operation.
• the inventors assume that because of the reticular structure of the MOF systems, the active metal and possibly - -
• MOF systems are not deposited on the structure of the MOF systems, comparable to the walls of the pores of a zeolite, but are included as discrete particles in the network.
• the metal contained in the MOF system can interact with the active metal. However, this interaction is usually very weak or absent.
• the MOF system is composed of metal atoms which are arranged on lattice sites. Between these metal atoms at least bidentate ligands are arranged, through which the metal atoms are connected.
• the metal atoms are located at the vertices of a cube, while the bidentate ligands are located along the edges of the cube.
• the size of the cube and thus the cavity enclosed therein can be tailored by the extent or length of the bidentate ligand.
• the metal component of the MOF system is selected from elements of groups Ia, Iia, IIIa, IV-Villa and Ib-Vib.
• the metals of the MOF system are selected from the group of Zn, Cu, Fe, Al, Sn, In, Ti.
• the at least bidentate ligand of the MOF system is preferably selected from compounds of the formula
• Z represents a carboxy group, a carbamide group, an amino group, a hydroxy group, a thiol group or a pyridyl group and
• R a is selected from - -
• A is hydrogen, alkyl groups having 1-6 carbon atoms, alkenyl groups having 2-6 C atoms, alkoxy groups having 1-6 carbon atoms and 1 to 3 oxygen atoms, halogen atoms or amino groups, where A may be identical or different at each occurrence and also several groups A can be provided, for example 2, 3 or 4.
• the degree of loading of the MOF system with the active metal is preferably at least 20% by weight, preferably at least 30% by weight, particularly preferably at least 40% by weight, based on the weight of the MOF system.
• the active metal is selected depending on the reaction to be catalyzed. Suitable active metals have already been mentioned above.
• the catalyst according to the invention may comprise at least one promoter metal or one promoter metal compound.
• the promoter metal may either be part of the MOF system or preferably be incorporated into the cavities of the MOF system like the active metal.
• promoter metal compound _ _ As promoter metal compound _ _
• the catalyst according to the invention preferably contains an oxide of the promoter metal. Suitable promoter metals have already been mentioned above.
• the catalyst according to the invention provides a very high surface area of the active metal.
• the active metal contained in the catalyst has a specific metal surface area of at least 5, preferably at least 10, more preferably at least 25 m 2 / g A k t ivmetaii-
• the catalyst comprises also a promoter which is in particular introduced into the voids of the MOF system so, the promoter preferably has a specific surface area of at least 25 m 2 / gp romot ORA m preferably of at least 100 2 / g Per m ot or / more preferably of at least 500 m 2 / g PR0i Notor on.
• the specific surface of the active metal can be determined by gas adsorption / desorption.
• N 2 O-reactive frontal chromatography for determining the specific surface area of copper.
• Analogous methods can be used for other active metals. They are generally based on the occupancy of the metal surface with a molecule of known space requirement, whereby the amount of adsorbed molecules is determined.
• the specific surface area of the promoter can be estimated by determining the degree of aggregation via X-ray absorption investigations and by BET surface area determination on the loaded support.
• the content of promoter component can be determined by elemental analysis (eg atomic absorption spectroscopy or energy dispersive X-ray absorption spectroscopy).
• An essential feature of the catalyst according to the invention is the extremely small size of the active metal particles which are embedded in the network in the form of nanoparticles.
• the size of the particles can be determined, for example, by transmission electron microscopy.
• the TEM images show small spheres of the active metal, which have a diameter of preferential - o -
• the active metal particles in the MOF system have a diameter in the range of about 0.5 to 4 nm.
• the catalyst obtainable by the process according to the invention has a number of advantages, as will be explained in the following example of an embodiment of the catalyst according to the invention as a catalyst for the synthesis of methanol.
• the catalyst according to the invention differs from the known Co / Zn / Al catalysts for the synthesis of methanol by the following criteria:
• the dispersion of the Cu component (or the active metal) is very high, at least 25 m 2 cu xg "1 ⁇ ie at the same mass fraction of catalytically active co-component catalyst of the invention is more active, or for the same specific
• activity namely activity based on the active metal surface area
• XRD X-ray diffraction
• the support is formed by a MOF system comprising defined voids. Due to the size of the cavities, the size of the active metal particles can be adjusted specifically.
• the catalytically active metal is therefore not in the form of a coating of the pore walls, but in the form of particles of a definite size, which is determined by the size of the cavity of the MOF system.
• the catalysts of the invention are characterized by a high activity based on the mass fraction of the catalytically active metal components. It is therefore particularly suitable for use as a catalyst for methanol synthesis or as a reformer in fuel cell technology.
• FIG. 1 shows a representation of a MOF-5 cage with four embedded [( ⁇ 5 -C 5 H 5 ) Pd ( ⁇ 3 -C 3 H 5 )] precursors, wherein the unit cell of the crystalline MOF-5 formally 8 cavities of this kind contains;
• Fig. 3 X-ray powder diffractograms of the systems: a) MOF-5; b) UV-Cu @ MOF-5 (photolytically reduced); c) Cu @ M0F-5 (after methanol catalysis, reduction by H 2 ); d) TEM image of Cu @ MOF-5 (sample b); - -
• Fig. 4 X-ray powder diffractograms of the systems a) MOF-5; b) Au @ MOF-5 (after reductive treatment with hydrogen at 190 ° C.); c) TEM image of Au @ MOF-5.
• IR spectra were recorded as KBr pellets with a Perkin Elmer FT-IR 1720 X spectrometer, NMR spectra were recorded on a Bruker DSX, 400 MHz spectrometer under MAS conditions in ZrO 2 rotors.
• AAS apparatus from Vario of type 6 (1998) was used.
• C, H, N analyzes were carried out with the CHNSO EL (1998) instrument from the same manufacturer.
• MOF-5 (50 mg) is placed in separate tubes with a portion of 100.0 mg precursor (1-3) in a Schlenk tube and heated in static vacuum (1 Pa) for 3 h at 343 K (for 2 and 3
• the defined intermediates [precursor] n @ MOF-5 thus obtained are characterized analytically as described above Samples of 40 mg are then added under H 2 at 23 ° C. (30 min).
• Precursor molecules elemental analysis volume precursor [al occupancy per cavity measured / calculated pore volume [cl
• the three-dimensional crystalline order of the MOF host lattice is unchanged after loading with [( ⁇ 5 -C 5 H 5 ) Pd ( ⁇ 3 -C 3 H 5 )], as the comparison of X-ray powder diffractograms shows before and after adsorption .
• the molecular volume of the precursor can be calculated using the structural data with Gaussian98 (B3LYP / SDD) as 196.6 ⁇ 3 .
• the Pd precursors [( ⁇ 5 -CsH 5 ) Pd (n 3 -C 3 Hs)] thus satisfy 36.3% of the unit cell, which equals 45.3% of the pore volume.
• other organometallic precursors for metal deposition are also absorbed without modification, eg [( ⁇ 5 -C 5 H 5 ) CuPMe 3 ] and [(CH 3 ) AuPMe 3 ].
• the size or shape selectivity is expected to be very high. Compared to [( ⁇ 5 -C 5 H 5 ) Pd ( ⁇ 3 -C 3 H 5 )] and [(CH 3 ) AuPMe 3 ], only slightly more space-filling [( ⁇ 5 -C 5 H 5 ) CuPMe 3 ], there are only two instead of four embedded molecules, although only 28% of the pore volume is then filled with precursor molecules [( ⁇ 5 -C 5 H 5 ) CuPMe 3 ].
• the composite Pd @ MOF-5 proved to be a moderately active catalyst for the hydrogenation of cyclooctene (COE), which was used as a test reaction [X. Mu, U. Bartmann, A. Guraya, GW Busser, U. Weckenmann, R. Fischer, M. Muhler, App. Catal. A 2003, 248, 85-95] (Table 2).
• the Au atoms or Au clusters (or nuclei) primarily formed by the decomposition of [(CH 3 ) AuPMe 3 ] in the open MOF structure are more mobile than the Cu or Pd clusters and are formed larger aggregates within the pores, such as diffusion to the outer surface of the MOF crystallites, for which the larger Au particles speak by 20 nm.
• the highly porous Au @ MOF-5 material was found to be inactive with respect to Au catalytic CO oxidation.
• the Au nanoparticles distributed in the MOF-5 lattice or on the surface of the MOF crystallites evidently lack the strong metal / carrier interaction or promotion required for the catalytic effect (Au / TiO 2 , Au / ZnO).

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Inorganic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Plasma & Fusion (AREA)
• Optics & Photonics (AREA)
• Electromagnetism (AREA)
• Catalysts (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37507750

Family Applications (1)

Country Status (5)

Cited By (1)

Families Citing this family (24)

Family Cites Families (15)

• 2005
  • 2005-08-10 DE DE102005037893A patent/DE102005037893A1/de not_active Withdrawn
• 2006
  • 2006-07-25 EP EP06776397A patent/EP1926553A1/de not_active Withdrawn
  • 2006-07-25 WO PCT/EP2006/007336 patent/WO2007017101A1/de active Application Filing
  • 2006-07-25 US US12/063,047 patent/US20090221418A1/en not_active Abandoned
  • 2006-08-08 AR ARP060103447A patent/AR057488A1/es not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events