Conducting polymer-grafted carbon material for fuel cell applications

• US 7,175,930 B2
• Filed: 05/23/2003
• Issued: 02/13/2007
• Est. Priority Date: 05/23/2002
• Status: Expired due to Fees

• Current Assignee: HSBC Bank USA National Association (HSBC Holdings plc)
• Original Assignee: Columbian Chemicals Company (Aditya Birla Management Corp Pvt Ltd.)
• Inventors: Srinivas, Bollepalli
• Primary Examiner(s): Ryan; Patrick Joseph
• Assistant Examiner(s): Parsons; Thomas H.
• Application Number:
  US10/445,090
• Publication Number:
  US 20040110052A1
• Time in Patent Office: 1,362 Days
• Field of Search: 429/33, 429/42, 252/522, 252/510, 252/500, 252/62.2
• US Class Current: 429/492
• CPC Class Codes: H01B 1/04 mainly consisting of carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01B 1/122 Ionic conductors
• CPC Class Codes: H01B 1/127 comprising five-membered aromatic rings in the main chain, e.g. polypyrroles, polythiophenes
• CPC Class Codes: H01B 1/128 comprising six-membered aromatic rings in the main chain, e.g. polyanilines, polyphenylenes
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/881 Electrolytic membranes
• CPC Class Codes: H01M 4/8839 Painting
• CPC Class Codes: H01M 4/92 Metals of platinum group H01M4/94 , H01M4/9058 take precedence
• CPC Class Codes: H01M 4/926 on carbon or graphite
• CPC Class Codes: H01M 8/1007 with both reactants being gaseous or vaporised H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1011 Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC]
• CPC Class Codes: H01M 8/1023 having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
• CPC Class Codes: H01M 8/1039 halogenated, e.g. sulfonated polyvinylidene fluorides
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A composition comprising particulate carbonaceous material and a conducting polymer containing hetero atoms. The composition can further comprise a metal. Devices comprising the composition can be constructed including supported electrocatalysts, membrane electrode assemblies, and fuel cells. A method for preparing the composition comprises oxidatively polymerizing a monomer of a conducting polymer containing hetero atoms in the presence of a carbonaceous material. The method grafts the conducting polymer to the carbonaceous material. The method can further comprise metallizing the polymer-grafted carbonaceous material.

Claims

1. A composition comprising

a particulate carbonaceous material,

a conducting polymer containing a hetero atom, and

a metal.

wherein the conducting polymer is grafted onto the carbonaceous material.

2. The composition of claim 1, wherein the carbonaceous material comprises carbon black.

3. The composition of claim 1, wherein the carbonaceous material comprises graphite, nanocarbon, fullerene, fullerenic material, finely divided carbon, or a mixture thereof.

4. The composition of claim 1, wherein the carbonaceous material is less than about 98% of the composition.

5. The composition of claim 1, wherein the carbonaceous material is about 50% to about 80% of the composition.

6. The composition of claim 1, wherein the conducting polymer comprises polyaniline, polypyrrole, polyfuran, polythiophene, or a mixture thereof.

7. The composition of claim 1, wherein the conducting polymer comprises polyaniline, polypyrrole, polyfuran, polythiophene, poly(p-phenylene-oxide), poly(p-phenylene-sulfide), a substituted conducting polymer thereof, or a mixture thereof.

8. The composition of claim 1, wherein the hetero atom is N, O, or S.

9. The composition of claim 1, wherein the hetero atom is about 0.2–

15% of the composition according to XPS data.

10. The composition of claim 1, wherein the conducting polymer is greater than about 0% and less than about 100% of the composition.

11. The composition of claim 1, wherein the conducting polymer is about 2% to about 50% of the composition.

12. The composition of claim 1, wherein the conducting polymer is about 20% to about 50% of the composition.

13. The composition of claim 1, wherein the polymer is concurrently formed and grafted by oxidatively polymerizing a monomer of the conducting polymer in the presence of the carbonaceous material.

14. The composition of claim 1, wherein the metal comprises platinum.

15. The composition of claim 1, wherein about 2% to about 80% of the composition is the metal.

16. The composition of claim 1, wherein about 2% to about 60% of the composition is the metal.

17. The composition of claim 1, wherein about 20% to about 40% of the composition is the metal.

18. The composition of claim 1, wherein the metal is uniformly distributed on the surface of the composition.

19. A method for preparing a carbon composition with enhanced electronic conductivity comprising

oxidatively polymerizing a monomer of a conducting polymer containing a hetero atom with particulate carbonaceous material to form a conducting polymer-grafted carbonaceous material, and then metallizing the conducting polymer grafted carbonaceous material.

20. The method of claim 19, wherein the carbonaceous material comprises graphite, nanocarbon, fullerene, fullerenic material, finely divided carbon, or a mixture thereof.

21. The method of claim 19, wherein the carbonaceous material comprises carbon black.

22. The method of claim 19, wherein the monomer of a conducting polymer comprises an amino aryl or a nitrogen heterocycle.

23. The method of claim 19, wherein the oxidative polymerization is in the presence of an oxidizing agent.

24. The method of claim 19, wherein the oxidatively polymerizing comprises adding an oxidizing agent to a mixture of the carbonaceous material and a monomer of the conducting polymer.

25. The method of claim 24, wherein the mixture of the carbonaceous material and the monomer of the conducting polymer further comprises an acid solvent whereby the mixture is a slightly acidic environment.

26. The method of claim 25, wherein the slightly acidic environment is a pH of less than 7.

27. The method of claim 25, wherein the slightly acidic environment is a pH of about 3 to about 4.

28. The method of claim 24, wherein the oxidizing agent comprises ammonium persulfate, ferric chloride, aluminum chloride, hydrogen peroxide, potassium permanganate, sodium permanganate, potassium chlorate, or a combination of oxidizing agents thereof.

29. The method of claim 19, wherein the conducting polymer comprises polyaniline, polypyrrole, polyfuran, polythiophene, poly(p-phenylene-oxide), poly(p-phenylene-sulfide), a substituted conducting polymer thereof, or a mixture thereof.

30. The method of claim 19, wherein the metallizing comprises adding a metal-containing material to the conducting polymer-grafted carbonaceous material.

31. The method of claim 30, wherein the metallizing further comprises adding a reducing agent.

32. The method of claim 31, wherein the reducing agent comprises formaldehyde, sodium borohydride, hydrogen, hydrazine, hydroxyl amine, or a mixture of reducing agents thereof.

33. The method of claim 30, wherein the metal-containing material comprises chloroplatinic acid, platinum nitrate, platinum halide, platinum cyanide, platinum sulfide, organoplatinum salt, or a mixture thereof.

34. The method of claim 19, wherein the metallizing comprises plantinizing.

35. A composition made by the method of claim 19.

36. A fuel cell, battery, or a capacitor device comprising a composition comprising

a particulate carbonaceous material, and

a conducting polymer containing a hetero atom,

wherein the conducting polymer is grafted onto the carbonaceous material,

wherein the composition is in a fuel cell, battery, or capacitor device.

37. The device of claim 36, wherein the composition further comprises a metal.

38. The device of claim 37, wherein the metal comprises platinum.

39. The device of claim 37, wherein the metal is 2–

80% of the device.

40. The device of claim 36, further comprising an electrolyte membrane.

41. The device of claim 40, wherein the electrolyte membrane is an ionically conductive polymer.

42. A fuel cell comprising an anode, a cathode, and a proton exchange membrane, wherein the anode and/or cathode comprises a composition comprising

a. a particulate carbonaceous material, and

b. a conducting polymer containing a hetero atom, wherein the conducting polymer is grafted onto the carbonaceous material.

43. The fuel cell of claim 42, wherein the composition further comprising a metal.

44. The fuel cell of claim 43, wherein the metal comprises platinum.