Fibrous Composite Catalytic Structure Having at Least Three Solid Phases

• US 20130085059A1
• Filed: 11/18/2012
• Published: 04/04/2013
• Est. Priority Date: 08/17/2007
• Status: Active Grant

• Current Assignee: Juzer Jangbarwala
• Original Assignee: Juzer Jangbarwala
• Inventors: Jangbarwala, Juzer
• Granted Patent: US 8,946,111 B2
• Time in Patent Office: Days
• US Class Current: 502/1
• CPC Class Codes: B01J 21/04 Alumina
• CPC Class Codes: B01J 21/18 Carbon
• CPC Class Codes: B01J 21/185 Carbon nanotubes carbon nanotubes per se C01B32/15
• CPC Class Codes: B01J 23/72 Copper
• CPC Class Codes: B01J 23/80 with zinc, cadmium or mercury
• CPC Class Codes: B01J 35/31 Density
• CPC Class Codes: B01J 35/33 Electric or magnetic properties
• CPC Class Codes: B01J 35/58 Fabrics or filaments
• CPC Class Codes: B01J 37/0201 Impregnation
• CPC Class Codes: B01J 37/08 Heat treatment B01J37/0009, B01J37/0018 take precedence
• CPC Class Codes: B01J 37/343 of ultrasonic wave energy
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/066 with fuel cells
• CPC Class Codes: C01B 2203/1017 characterised by the form of the structure
• CPC Class Codes: C01B 2203/1076 Copper or zinc-based catalysts
• CPC Class Codes: C01B 2203/1223 Methanol
• CPC Class Codes: C01B 3/326 characterised by the catalyst
• CPC Class Codes: H01M 8/0631 Reactor construction specially adapted for combination reactor/fuel cell hydrogen C01B3/00; reactors for physicochemical processes B01J19/00
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 20/52 : using catalysts, e.g. selective catalysts
• CPC Class Codes: Y10S 977/742 : Carbon nanotubes, CNTs
• CPC Class Codes: Y10T 428/23921 : With particles
• CPC Class Codes: Y10T 428/23986 : With coating, impregnation, or bond
• CPC Class Codes: Y10T 428/249928 : Fiber embedded in a ceramic, glass, or carbon matrix
• CPC Class Codes: Y10T 428/249929 : Fibers are aligned substantially parallel
• CPC Class Codes: Y10T 428/249953 : Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/25 : Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/2913 : Rod, strand, filament or fiber
• CPC Class Codes: Y10T 428/2918 : including free carbon or carbide or therewith [not as steel]
• CPC Class Codes: Y10T 428/2927 : including structurally defined particulate matter
• CPC Class Codes: Y10T 428/294 : including metal or compound thereof [excluding glass, ceramic and asbestos]
• CPC Class Codes: Y10T 442/184 : Nonwoven scrim
• CPC Class Codes: Y10T 442/186 : Comprising a composite fiber

Abstract

Permeable composite fibrous catalytic sheets comprised of at least three distinct solid phases. A first solid phase is a 3-dimensional porous network of a non-conductive porous ceramic material. A second solid phase is an electrically conductive phase comprised of randomly oriented electrically conductive fibers. A third phase is comprised of catalytic particles dispersed on said 3-dimensional porous network, said conductive fibers, or both. A fourth phase can be present, which fourth phase is comprised one or more conductive species or one or more non conductive species embedded in said first solid phase.

Claims

1. A substantially rigid permeable composite catalytic sheet-like structure comprised of at least three distinct solid phases wherein:

i) a first solid phase is comprised of a 3-dimentional substantially continuous network of a non-conductive porous ceramic material;

ii) a second solid phase is comprised of a plurality of electrically conductive fibers integrated throughout the 3-dimensional substantially continuous network of non-conductive porous ceramic material;

iii) a third solid phase comprised of an effective amount of catalyst particles dispersed throughout the non-conductive porous ceramic material, the plurality of electrically conductive fibers, or both.

2. The catalytic sheet of claim 1 wherein there is a fourth solid phase comprised of a plurality of one or more conductive or non-conductive materials embedded within said first solid phase.

3. The catalytic sheet of claim 1 wherein the conductive fibers are selected from the group consisting of carbon fibers, graphitic fibers, and polymer fibers enhanced with graphene, graphite, carbon and graphitic nanotube, carbon and graphitic nanofibers.

4. The catalytic sheet of claim 3 wherein the conductive fibers are graphitic fibers.

5. The catalytic sheet of claim 1 wherein the conductive fibers are graphitic fibers.

6. The catalytic sheet of claim 1 wherein the ceramic material of the first solid phase is selected from the group consisting of alumina, silica, silica-alumina, titania, zirconia, and magnesia.

7. The catalytic sheet of claim 6 wherein the ceramic material is alumina.

8. The catalytic sheet of claim 2 wherein the fourth solid phase is a comprised of one or more conductive materials selected from the group consisting of graphene, and carbon and graphitic nanostructures, including nanofibers, nanotubes, and nanoribbons.

9. The catalytic sheet of claim 2 wherein the fourth solid phase is a non-conductive phase comprised of a non-conductive material selected from the group consisting of ceramic fibers, zirconia fibers, alumina fibers, aluminosilica fibers, aluminoborosilicate fibers, ceramic nanostructures, and silicon carbide fibers.

10. The catalytic sheet of claim 9 wherein the ceramic fibers are selected from the group consisting of ceramic nanostructures and silicon carbide fibers.

11. The catalytic sheet of claim 1 wherein the catalyst is a methanol reforming catalyst.

12. The catalytic sheet of claim 11 wherein the methanol reforming catalyst contains copper.

13. The catalyst sheet of claim 11 wherein the methanol reforming catalyst contains both copper and zinc oxide.

14. A process for producing catalytic sheets comprised of a substantially rigid permeable composite catalytic sheet-like structure comprised of at least three distinct solid phases wherein:

i) a first solid phase is comprised of a 3-dimentional substantially continuous network of a non-conductive porous ceramic material;

ii) a second solid phase is comprised of a plurality of electrically conductive fibers integrated throughout the 3-dimensional substantially continuous network of non-conductive porous ceramic material;

iii) a third solid phase comprised of an effective amount of catalyst particles dispersed throughout the non-conductive porous ceramic material, the plurality of electrically conductive fibers, or both;

which process comprises;

a) providing a porous mat of randomly oriented electrically conductive fibers;

b) preparing a blend of an effective amount of catalyst particles in a dispersing liquid;

c) passing said blend through said porous mat of electrically conductive fibers an effective amount of time until a predetermined amount of catalyst particles are deposited onto the carbon fibers of said porous mat;

d) driving-off substantially all liquid dispersing agent that may be present on said catalyst-containing conductive fiber mat;

e) preparing a ceramic sol;

f) introducing said ceramic sol into an open mold at least as large as said conductive fiber mat;

g) submerging said catalyst-containing conductive fiber mat into said ceramic sol for an effective amount of time to allow substantially all of said catalyst particles to migrate from said carbon fibers to said ceramic sol;

h) driving-off substantially all liquid from step g) above thereby resulting in a 3-dimensional porous network of ceramic material intermingled throughout said conductive fiber mat, which 3-dimensional porous network of non-conductive ceramic material now supports substantially all of said catalyst particles;

i) calcining dried intermingled 3-dimensional porous network of ceramic material and carbon fiber mat of step g) above in an oxygen-containing atmosphere and at a temperature from about 100°

C. to about 500°

C.; and

j) subjecting said calcined 3-dimensional porous network of ceramic material and conductive fiber mat of step h) above in a hydrogen-containing atmosphere at a temperature from about 200°

C. to about 500°

C. for an effective amount of time to activate substantially all of said catalyst particles, thereby resulting in a catalytic sheet product.

15. The process of claim 14 wherein the dispersing liquid is selected from the group consisting of water and C₁ to C₃ aliphatic alcohols.

16. The process of claim 14 wherein the conductive fibers of the conductive fiber mat are selected from the group consisting of carbon fibers, graphitic fibers, and polymer fibers enhanced with grapheme, graphite, carbon and graphitic nanotube, carbon and graphitic nanofibers.

17. The process of claim 16 wherein the conductive fibers are graphitic fibers.

18. The process of claim 14 wherein the catalyst is a methanol reforming catalyst.

19. The process of claim 14 wherein there is a fourth solid phase comprised of a plurality of one or more conductive or non-conductive materials embedded within said first solid phase.

20. The process of claim 14 wherein the conductive fibers are selected from the group consisting of carbon fibers, graphitic fibers, and polymer fibers enhanced with grapheme, graphite, carbon and graphitic nanotube, carbon and graphitic nanofibers.

21. The process of claim 19 wherein the fourth solid phase is a comprised of one or more conductive materials selected from the group consisting of graphene, and carbon and graphitic nanostructures, including nanofibers, nanotubes, and nanoribbons.

22. The process of claim 19 wherein the fourth solid phase is a non-conductive phase comprised of a non-conductive material selected from the group consisting of zirconia fibers, alumina fibers, aluminosilica fibers, aluminoborosilicate fibers, ceramic nanostructures, and silicon carbide fibers.

23. The process of claim 14 wherein the ceramic material is selected from the group consisting of alumina, silica, silica-alumina, titania, and magnesia.

24. The process of claim 23 wherein the ceramic material is alumina.

25. The process of claim 14 wherein there is also present in an effective amount of graphite nanofibers.

26. The process of claim 25 wherein the graphitic nanofibers are comprised of graphite platelets that are aligned parallel, perpendicular or at an angle to the longitudinal axis of the nanofiber.

27. A process for producing catalytic sheets comprised of three solid phases wherein a first solid phase is comprised of a plurality of randomly oriented electrically conductive fibers, a second solid phase is comprised of a 3-dimensional network of a substantially non-conductive porous ceramic material intermingled with said first solid phase, and a third solid phase comprised of a plurality of catalyst particles dispersed on said 3-dimentional network of porous ceramic material;

which process comprises;

a) blending together an effective amount of catalyst particles for an intended reaction and an effective amount of electrically conductive carbon fibers thereby resulting in a blend;

b) mixing at least a portion of said blend with a dispersing agent thereby resulting in a mixture;

c) introducing at least a portion of said mixture and an effective amount of a ceramic sol into a mold;

d) driving-off substantially all of any liquid from the mixture thereby resulting in a dried 3-dimensional porous network of non-conductive ceramic material intermingled with randomly dispersed electrically conductive fibers;

e) calcining dried 3-dimensional porous network of ceramic material and conductive fiber mat of step g) above in an oxygen-containing atmosphere and at a temperature from about 100°

C. to about 500°

C.; and

f) subjecting said calcined 3-dimensional porous network of non-conductive ceramic material/randomly dispersed conductive fibers of step e) above in a hydrogen-containing atmosphere at a temperature from about 200°

C. to about 500°

C. for an effective amount of time to activate substantially all of said catalyst particles, thereby resulting in a catalytic sheet product.

28. The process of claim 27 wherein the conductive fibers of the conductive fiber mat are selected from the group consisting of carbon fibers, graphitic fibers, and polymer fibers enhanced with grapheme, graphite, carbon and graphitic nanotube, carbon and graphitic nanofibers.

29. The process of claim 28 wherein the conductive fibers are graphitic.

30. The process of claim 27 wherein there is a fourth solid phase comprised of a plurality of one or more conductive or non-conductive materials embedded within said first solid phase.

31. The process of claim 30 wherein the fourth solid phase is a comprised of one or more conductive materials selected from the group consisting of graphene, and carbon and graphitic nanostructures, including nanofibers, nanotubes, and nanoribbons.

32. The process of claim 30 wherein the fourth solid phase is a non-conductive phase comprised of a non-conductive material selected from the group consisting of zirconia fibers, alumina fibers, aluminosilica fibers, aluminoborosilicate fibers, ceramic nanostructures, and silicon carbide fibers.

33. The process of claim 27 wherein the catalyst particles are a methanol reforming catalyst.

34. The process of claim 27 wherein the ceramic material is selected from the group consisting of alumina, silica, silica-alumina, titania, and magnesia.

35. The process of claim 34 wherein the ceramic material is alumina.