Conducting polymer-grafted carbon material for fuel cell applications

• US 20040166401A1
• Filed: 02/25/2004
• Published: 08/26/2004
• Est. Priority Date: 05/23/2002
• Status: Active Grant

• Current Assignee: HSBC Bank USA National Association (HSBC Holdings plc)
• Original Assignee: HSBC Bank USA National Association (HSBC Holdings plc)
• Inventors: Srinivas, Bollepalli
• Granted Patent: US 7,459,103 B2
• Time in Patent Office: Days
• US Class Current: 429/44
• 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 4/92 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 60/50 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 with ozone 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 method for preparing a carbon with enhanced electronic conductivity comprising

oxidatively polymerizing with an oxidizing agent comprising ozone a monomer of a conducting polymer containing hetero atoms with particulate carbonaceous material to form a conducting polymer-grafted carbonaceous material.

2. The method of claim 1, wherein the carbonaceous material is carbon black, graphite, nanocarbons, fullerenes, fullerinic material, finely divided carbon, or mixtures thereof.

3. The method of claim 1, wherein the carbonaceous material is carbon black.

4. The method of claim 1, wherein the monomer of a conducting polymer is an amino aryl or a nitrogen heterocycle.

5. The method of claim 1, wherein the oxidatively polymerizing comprises adding ozone to a mixture of the carbonaceous material and the monomer of the conducting polymer.

6. The method of claim 5, wherein the mixture of the carbonaceous material and the monomer of the conducting polymer further comprises an acid solvent to form a slightly acidic environment.

7. The method of claim 6, wherein the slightly acidic environment is a pH of about less than 7.

8. The method of claim 6, wherein the slightly acidic environment is a pH of about 3 to about 4.

9. The method of claim 1, wherein the conducting polymer is polyaniline, polypyrrole, polyfuran, polythiophene, poly(p-phenylene-oxide), poly(p-phenylene-sulfide), substituted conducting polymers, or a mixture thereof.

10. The method of claim 1, further comprising metallizing the conducting polymer-grafted carbonaceous material.

11. The method of claim 10, wherein the metallizing comprises adding a metal-containing material to the conducting polymer-grafted carbonaceous material.

12. The method of claim 11, wherein the metallizing further comprises adding a reducing agent.

13. The method of claim 10, wherein the metallizing is plantinizing.

14. The method of claim 12, wherein the reducing agent is formaldehyde, sodium borohydride, hydrogen, hydrazine, hydroxyl amine, or a mixture of reducing agents.

15. The method of claim 11, wherein the metal-containing material is chloroplatinic acid, platinum nitrate, platinum halides, platinum cyanide, platinum sulfide, organoplatinum salts, or a mixture thereof.

16. A composition made by the method of claim 1.