WO1996035510A1 - Carbides and nitrides of transition elements with controlled porosity - Google Patents
Carbides and nitrides of transition elements with controlled porosity Download PDFInfo
- Publication number
- WO1996035510A1 WO1996035510A1 PCT/BR1996/000011 BR9600011W WO9635510A1 WO 1996035510 A1 WO1996035510 A1 WO 1996035510A1 BR 9600011 W BR9600011 W BR 9600011W WO 9635510 A1 WO9635510 A1 WO 9635510A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- nitrides
- carbides
- transition elements
- porous
- preparation
- Prior art date
Links
- 150000004767 nitrides Chemical class 0.000 title claims abstract description 16
- 150000001247 metal acetylides Chemical class 0.000 title claims abstract description 12
- 230000007704 transition Effects 0.000 title claims abstract description 9
- 150000001875 compounds Chemical class 0.000 claims abstract description 5
- 238000000034 method Methods 0.000 claims abstract description 5
- 229920000168 Microcrystalline cellulose Polymers 0.000 claims abstract description 3
- 235000019813 microcrystalline cellulose Nutrition 0.000 claims abstract description 3
- 239000008108 microcrystalline cellulose Substances 0.000 claims abstract description 3
- 229940016286 microcrystalline cellulose Drugs 0.000 claims abstract description 3
- 238000000465 moulding Methods 0.000 claims abstract 2
- 239000002243 precursor Substances 0.000 claims description 4
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 235000012438 extruded product Nutrition 0.000 claims description 2
- 238000002485 combustion reaction Methods 0.000 claims 1
- 238000002360 preparation method Methods 0.000 abstract description 7
- 230000003197 catalytic effect Effects 0.000 abstract description 3
- 238000006555 catalytic reaction Methods 0.000 abstract description 3
- 238000006243 chemical reaction Methods 0.000 abstract description 2
- 238000001935 peptisation Methods 0.000 abstract description 2
- 239000003054 catalyst Substances 0.000 abstract 1
- 238000009792 diffusion process Methods 0.000 abstract 1
- 238000001125 extrusion Methods 0.000 abstract 1
- 239000002253 acid Substances 0.000 description 5
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 239000000908 ammonium hydroxide Substances 0.000 description 2
- 235000010980 cellulose Nutrition 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 239000011733 molybdenum Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229910052723 transition metal Inorganic materials 0.000 description 2
- 150000003624 transition metals Chemical class 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 229910001009 interstitial alloy Inorganic materials 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 238000006317 isomerization reaction Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
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
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/20—Carbon compounds
- B01J27/22—Carbides
-
- 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
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/24—Nitrogen compounds
-
- 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
-
- 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
- B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
- B01J37/0018—Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)
-
- 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
- B01J35/64—Pore diameter
- B01J35/647—2-50 nm
-
- 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
- B01J35/66—Pore distribution
- B01J35/69—Pore distribution bimodal
Definitions
- the present invention relates to a preparation method of carbides and nitrides of transition elements in extruded shape from their oxides, leading to a controlled porous volume and distribution, destinated to catalytic use like in isomerization or hydrogenation reactions or in reactions used to gas generation like hydrazine decomposition in propulsion systems .
- Carbides and nitrides are interstitial alloys formed by incorporating carbon and nitrogen into the cristalline nets of the transition metals oxide. These alloys show metallic characteristics which give them catalytic activity similar to various metals, like iridium, platinum and paladium. The important characteristics of such compounds, besides being extremely hard, are corrosion resistance and high melting point. As direct consequence of these properties carbides and nitrides are used not only in catalysis, but also in cutting tools, structural parts, etc. The use in catalysis came from the development by Boudart team of a preparation method which resulted in carbides and nitrides of high specific area.
- This preparation method consists of a reduction of oxide of the transition metal, using gaseous amonia for that in the nitrides case or a hydrogen and methane mixture in the carbides case, and increasing the temperature of the precursor oxide in a uniform and smooth way.
- This preparation method produces materials with high specific area, the obtained porous structure can not be controlled, leading to a porous diameter not higher than 50 angstroms.
- the invention herein is different from the nowadays existing techniques by the possibility of obtaining carbides and nitrides of transition elements in the extruded shape with the intended porosity.
- the preparation method consists in obtaining the transition elements acids, tungstic for the tungsten and molybdic for the molybdenum, in a peptizable shape. These acids which were obtained in the colloidal shape when formed at low temperatures, in powder shape, are mixtured with microcrystalline cellulose, also in powder shape.
- the mixture is peptized using as a peptization agent an ammonium hydroxide dilluted solution.
- the obtained product is then extruded with the aid of an extruder.
- the thermal treatment of the extruded product involves drying at 60°C and after at 120°C, both during approximately 12 hours. After that a calcination at 600°C, during 3 hours, is made with the goal of transforming the acid in its corresponding oxide and to burn the cellulose remaining in the acid.
- the ellimination of this cellulose generates, in the resulting oxide, a porosity that can be controlled by concentrating this compound mixtured with the acid or by the ammonium hydroxide content used as the peptizing agent.
- Figure 1 shows the porous structure obtained by this method for the molybdenum carbide_case.
- the Y axis is the incremental specific volume (dV/dD) in cm /g, where V is the porous specific volume and D is the porous diameter.
- X axis the porous diameter, in angstroms, is shown in a logarithmic scale.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Catalysts (AREA)
- Ceramic Products (AREA)
Abstract
The present invention relates to a preparation method of carbides and nitrides of transition elements in extruded shape and from their oxides, with controlled porous volume and distribution. The meso and macroporous are generated by polymeric organic molecules such as microcrystalline cellulose, which after being burned form a more opened porous structure. The molding process involves the obtention of intermediate compounds that are susceptible to peptization and later extrusion. The preparation of these compounds, with porous diameter greater than 50 angstroms, implies in a range of catalytic reactions applications since more opened porous structures allow the catalytic process of larger molecules. Besides, in this way, there are less problems related to heat and mass diffusion processes. Problems which appear when dealing with very active catalysts and/or very exothermic reactions.
Description
Descriptive Report of the Patent of Invention "CARBIDES AND NITRIDES OF TRANSITION ELEMENTS WITH CONTROLLED POROSITY" . The present invention relates to a preparation method of carbides and nitrides of transition elements in extruded shape from their oxides, leading to a controlled porous volume and distribution, destinated to catalytic use like in isomerization or hydrogenation reactions or in reactions used to gas generation like hydrazine decomposition in propulsion systems .
Carbides and nitrides are interstitial alloys formed by incorporating carbon and nitrogen into the cristalline nets of the transition metals oxide. These alloys show metallic characteristics which give them catalytic activity similar to various metals, like iridium, platinum and paladium. The important characteristics of such compounds, besides being extremely hard, are corrosion resistance and high melting point. As direct consequence of these properties carbides and nitrides are used not only in catalysis, but also in cutting tools, structural parts, etc. The use in catalysis came from the development by Boudart team of a preparation method which resulted in carbides and nitrides of high specific area. This preparation method consists of a reduction of oxide of the transition metal, using gaseous amonia for that in the nitrides case or a hydrogen and methane mixture in the carbides case, and increasing the temperature of the
precursor oxide in a uniform and smooth way. Although this preparation method produces materials with high specific area, the obtained porous structure can not be controlled, leading to a porous diameter not higher than 50 angstroms. The invention herein is different from the nowadays existing techniques by the possibility of obtaining carbides and nitrides of transition elements in the extruded shape with the intended porosity. The preparation method consists in obtaining the transition elements acids, tungstic for the tungsten and molybdic for the molybdenum, in a peptizable shape. These acids which were obtained in the colloidal shape when formed at low temperatures, in powder shape, are mixtured with microcrystalline cellulose, also in powder shape.
After this phase the mixture is peptized using as a peptization agent an ammonium hydroxide dilluted solution. The obtained product is then extruded with the aid of an extruder. The thermal treatment of the extruded product involves drying at 60°C and after at 120°C, both during approximately 12 hours. After that a calcination at 600°C, during 3 hours, is made with the goal of transforming the acid in its corresponding oxide and to burn the cellulose remaining in the acid. The ellimination of this cellulose generates, in the resulting oxide, a porosity that can be controlled by concentrating this compound mixtured with the acid or by the ammonium hydroxide content used as the peptizing agent. After this phase the carbides and nitrides
are obtained by heating these precursors in a uniform and smooth way in a gaseous amonia environment, for nitrides, or in a hydrogen and methane environment, for carbides. TIPICAL EXAMPLE
Figure 1 shows the porous structure obtained by this method for the molybdenum carbide_case. The Y axis is the incremental specific volume (dV/dD) in cm /g, where V is the porous specific volume and D is the porous diameter. In X axis the porous diameter, in angstroms, is shown in a logarithmic scale. The mode 1 shown in figure as region 1 has coordinates X=40 and Y=0.08 and represents the porosity generated during the precursor oxide transformation in carbide or nitride. The mode 2, having as coordinates X=1000 and Y=0.15, represents the porosity generated by the burning of polymeric materials and their X and Y values depend on the content and kind of the employed polymer.
Claims
1 - Carbides and nitrides of transition elements characterized by the obtention of these compounds with controlled porous volume and distribution, used to catalitic applications in_general.
2 - Carbides and nitrides of transition elements as in claim 1, characterized by the use of long chain materials susceptible to combustion, used for generation of meso and macroporous, such_as microcrystalline cellulose.
3 - Carbides and nitrides of transition elements as in claim 1, characterized by the use of amonium hydroxide as peptizing agent in the molding process extruded products obtention - of the carbides and nitrides precursors.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP96905624A EP0824371A1 (en) | 1995-05-11 | 1996-03-19 | Carbides and nitrides of transition elements with controlled porosity |
| JP8533616A JPH11510427A (en) | 1995-05-11 | 1996-03-19 | Controlled porosity transition element carbides and nitrides |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BR9501693A BR9501693A (en) | 1995-05-11 | 1995-05-11 | Carbides and nitrides of transition elements with controlled porosity |
| BRPI9501693-7 | 1995-05-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1996035510A1 true WO1996035510A1 (en) | 1996-11-14 |
Family
ID=4061227
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/BR1996/000011 WO1996035510A1 (en) | 1995-05-11 | 1996-03-19 | Carbides and nitrides of transition elements with controlled porosity |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0824371A1 (en) |
| JP (1) | JPH11510427A (en) |
| BR (1) | BR9501693A (en) |
| CA (1) | CA2219797A1 (en) |
| WO (1) | WO1996035510A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10002117A1 (en) * | 2000-01-20 | 2001-08-16 | Geesthacht Gkss Forschung | Catalysis of the hydrogen sorption kinetics of hydrides by nitrides and carbides |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4271041A (en) * | 1979-02-08 | 1981-06-02 | The Board Of Trustees Of Leland Stanford Junior University | High surface area molybdenum oxycarbide catalysts |
| US4851206A (en) * | 1981-07-15 | 1989-07-25 | The Board Of Trustees Of The Leland Stanford Junior University, Stanford University | Methods and compostions involving high specific surface area carbides and nitrides |
| US4940684A (en) * | 1987-09-28 | 1990-07-10 | President Of Agency Of Industrial Science And Technology | Method for preparing a catalyst supported on silicon carbide or silicon nitride |
| US5139987A (en) * | 1990-09-06 | 1992-08-18 | Pechiney Recherche | Process for activating the surface of carbides of heavy metals with a large specific surface for catalytic reactions |
-
1995
- 1995-05-11 BR BR9501693A patent/BR9501693A/en not_active Application Discontinuation
-
1996
- 1996-03-19 EP EP96905624A patent/EP0824371A1/en not_active Withdrawn
- 1996-03-19 WO PCT/BR1996/000011 patent/WO1996035510A1/en not_active Application Discontinuation
- 1996-03-19 JP JP8533616A patent/JPH11510427A/en active Pending
- 1996-03-19 CA CA002219797A patent/CA2219797A1/en not_active Abandoned
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4271041A (en) * | 1979-02-08 | 1981-06-02 | The Board Of Trustees Of Leland Stanford Junior University | High surface area molybdenum oxycarbide catalysts |
| US4851206A (en) * | 1981-07-15 | 1989-07-25 | The Board Of Trustees Of The Leland Stanford Junior University, Stanford University | Methods and compostions involving high specific surface area carbides and nitrides |
| US4940684A (en) * | 1987-09-28 | 1990-07-10 | President Of Agency Of Industrial Science And Technology | Method for preparing a catalyst supported on silicon carbide or silicon nitride |
| US5139987A (en) * | 1990-09-06 | 1992-08-18 | Pechiney Recherche | Process for activating the surface of carbides of heavy metals with a large specific surface for catalytic reactions |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10002117A1 (en) * | 2000-01-20 | 2001-08-16 | Geesthacht Gkss Forschung | Catalysis of the hydrogen sorption kinetics of hydrides by nitrides and carbides |
Also Published As
| Publication number | Publication date |
|---|---|
| BR9501693A (en) | 1997-09-16 |
| EP0824371A1 (en) | 1998-02-25 |
| JPH11510427A (en) | 1999-09-14 |
| CA2219797A1 (en) | 1996-11-14 |
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