Sulfonated conducting polymer-grafted carbon material for fuel cell applications
View Patent ↗A composition comprising particulate carbonaceous material and a sulfonated 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 and sulfonating the polymer or the monomer. The method grafts the sulfonated conducting polymer to the carbonaceous material. The method can further comprise metallizing the polymer-grafted carbonaceous material.
1. A particulate composition comprising
a particulate carbonaceous material,
a sulfonated conducting polymer containing a hetero atom, and a metal,
wherein the sulfonated 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 sulfonated 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 sulfonated conducting polymer is about 20% to about 50% of the composition.
13. The composition of claim 1 , wherein the polymer comprises about 0.1 to about 3 equivalent sulfonate groups per monomer unit.
14. The composition of claim 13 , wherein the polymer comprises about 0.4 equivalent sulfonate groups per monomer unit.
15. The composition of claim 13 , wherein the polymer comprises about 1 equivalent sulfonate groups per monomer unit.
16. The composition of claim 13 , wherein the polymer comprises about 2 equivalent sulfonate groups per monomer unit.
17. The composition of claim 1 , wherein the sulfonated polymer is concurrently formed and grafted by oxidatively polymerizing a monomer of the conducting polymer in the presence of the carbonaceous material followed by direct sulfonation of the resulting polymer-carbonacaceous material.
18. The composition of claim 1 , wherein the sulfonated polymer is concurrently formed and grafted by oxidatively polymerizing a sulfonated monomer of the conducting polymer in the presence of the carbonaceous material.
19. The composition of claim 1 , wherein the metal comprises platinum.
20. The composition of claim 1 , wherein about 2% to about 80% of the composition is the metal.
21. The composition of claim 1 , wherein about 2% to about 60% of the composition is the metal.
22. The composition of claim 1 , wherein about 20% to about 40% of the composition is the metal.
23. The composition of claim 1 , wherein the metal is uniformly distributed on the surface of the composition.
24. A method for preparing a particulate carbon composition with enhanced electronic and protonic conductivity comprising
oxidatively polymerizing monomer of a conducting polymer containing a hetero atom with particulate carbonaceous material to form a conducting polymer-grafted carbonaceous material, wherein either the monomer is sulfonated or the polymer is subsequently sulfonated, to thereby produce a sulfonated conducting polymer-grafted carbonaceous material; and then metallizing the sulfonated conducting polymer-grafted carbonaceous material.
25. The method of claim 24 , wherein the carbonaceous material comprises graphite, nanocarbon, fullerene, fullerinic material, finely divided carbon, or a mixture thereof.
26. The method of claim 24 , wherein the carbonaceous material comprises carbon black.
27. The method of claim 24 , wherein the monomer of a conducting polymer comprises an amino aryl or a nitrogen heterocycle.
28. The method of claim 24 , wherein the oxidative polymerization is in the presence of an oxidizing agent.
29. The method of claim 24 , wherein the oxidatively polymerizing comprises adding an oxidizing agent to a mixture of the carbonaceous material and a monomer of the conducting polymer.
30. The method of claim 29 , 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.
31. The method of claim 30 , wherein the slightly acidic environment is a pH of less than 7.
32. The method of claim 30 , wherein the slightly acidic environment is a pH of about 3 to about 4.
33. The method of claim 29 , wherein the oxidizing agent comprises ammonium persulfate, sodium persulfate, ferric chloride, aluminum chloride, hydrogen peroxide, potassium permanganate, sodium permanganate, potassium chlorate, or a combination of oxidizing agents thereof.
34. The method of claim 24 , 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.
35. The method of claim 24 , wherein the polymer is directly sulfonated after oxidatively polymerizing the monomer with the carbonaceous material.
36. The method of claim 24 , wherein the monomer is a sulfonated monomer of the conducting polymer.
37. The method claim 35 , wherein the direct sulfonation is by addition of a sulfonating agent.
38. The method claim 37 , wherein the sulfonating agent is chlorosulfonic acid.
39. The method claim 37 , wherein the sulfonating agent is acetylsulfonic acid.
40. The method of claim 24 , wherein the metallizing comprises adding a metal-containing material to the conducting polymer-grafted carbonaceous material.
41. The method of claim 40 , wherein the metallizing further comprises adding a reducing agent.
42. The method of claim 24 , wherein the metallizing is plantinizing.
43. The method of claim 41 , wherein the reducing agent comprises formaldehyde, sodium borohydride, hydrogen, hydrazine, hydroxyl amine, or a mixture of reducing agents thereof.
44. The method of claim 40 , wherein the metal-containing material comprises chloroplatinic acid, platinum nitrate, platinum halide, platinum cyanide, platinum sulfide, organoplatinum salt, or a mixture thereof.
45. A composition made by the method comprising
oxidatively polymerizing monomer of a conducting polymer containing a hetero atom with particulate carbonaceous material to form a conducting polymer-grafted carbonaceous material, wherein either the monomer is sulfonated or the polymer is subsequently sulfonated, to thereby produce a sulfonated conducting polymer-grafted carbonaceous material; then metallizing the sulfonated conducting polymer-grafted carbonaceous material.