Fuel cell catalyst layer

1. A fuel cell catalyst layer, comprising:

carbon-containing particles; and

a moiety covalently bound to the carbon-containing particles,

wherein:

a hydrophobicity of the fuel cell catalyst layer is greater than a hydrophobicity of the carbon-containing particles;

the moiety comprises —(CH 2 ) x (CF 2 ) y Ar(αH, βX) z ;

x, y, and z are each independently an integer from 0-10, wherein x, y, and z are each greater than zero;

Ar(αH, βX) is an aromatic ring with α hydrogen atoms and β halogen atoms; and

at least some of the β halogen atoms are fluorine atoms.

2. The fuel cell catalyst layer of claim 1 , wherein the carbon-containing particles are in the form of a sheet.

3. The fuel cell catalyst layer of claim 1 , wherein the moiety is selected from the group consisting of aromatic moieties, halogens, hydrocarbon moieties, and combinations thereof.

4. The fuel cell catalyst layer of claim 1 , wherein the fuel cell catalyst layer comprises a catalyst.

5. The fuel cell catalyst layer of claim 4 , wherein the catalyst is supported by the carbon-containing particles.

6. The fuel cell catalyst layer of claim 4 , wherein the fuel cell catalyst layer comprises from about one weight percent to about 50 weight percent of the catalyst.

7. The fuel cell catalyst layer of claim 4 , wherein the catalyst comprises platinum.

8. The fuel cell catalyst layer of claim 1 , further comprising a proton conducting material.

9. The fuel cell catalyst layer of claim 8 , wherein the fuel cell catalyst layer comprises from about five weight percent to about 45 weight percent of the proton conducting material.

10. The fuel cell catalyst layer of claim 8 , wherein the proton conducting material comprises a perfluorinated ionomer.

11. A fuel cell system, comprising:

a first fuel cell flow plate;

a second fuel cell flow plate;

an electrolyte between the first and second fuel cell flow plates;

a fuel cell catalyst layer between the first fuel cell flow plate and the electrolyte, the fuel cell catalyst layer comprising:

carbon-containing particles; and

a moiety covalently bound to the carbon-containing particles,

wherein:

a hydrophobicity of the fuel cell catalyst layer is greater than a hydrophobicity of the carbon-containing particles;

the moiety comprises —(CH 2 ) x (CF 2 ) y Ar(αH,βX) z ;

x, y, and z are each independently an integer from 0-10, wherein x, y, and z are each greater than zero;

Ar(αH, βX) is an aromatic ring with a hydrogen atoms and β halogen atoms; and

at least some of the β halogen atoms are fluorine atoms.

12. The fuel cell system of claim 11 , wherein the fuel cell is a proton-exchange membrane fuel cell.

13. The fuel cell system of claim 11 , wherein the fuel cell is a direct alcohol fuel cell.

14. The fuel cell system of claim 11 , wherein the fuel cell is a direct-feed liquid fuel cell.

15. A method of making a fuel cell catalyst layer, the method comprising:

covalently bonding carbon-containing particles with a moiety to provide the fuel cell catalyst layer,

wherein:

the fuel cell catalyst layer has a hydrophobicity greater than a hydrophobicity of the carbon-containing particles;

the moiety comprises —(CH 2 ) x (CF 2 ) y Ar(αH, βX) z ;

x, y, and z are each independently an integer from 0-10, wherein x, y, and z are each greater than zero;

Ar(αH, βX) is an aromatic ring with α hydrogen atoms and β halogen atoms; and

at least some of the β halogen atoms are fluorine atoms.

16. The method of claim 15 , wherein the carbon-containing particles are in the form of a sheet.

17. The method of claim 15 , further comprising, after chemically reacting the particles with the moiety, incorporating a proton conducting material into the fuel cell catalyst layer.

18. The method of claim 15 , further comprising incorporating a catalyst into the fuel cell catalyst layer.

19. The method of claim 18 , wherein the catalyst comprises platinum.

20. The method of claim 18 , wherein the catalyst is incorporated into the fuel cell catalyst layer before the carbon-containing particles are chemically reacted with the moiety.

21. The method of claim 18 , wherein the catalyst is incorporated into the fuel cell catalyst layer after the carbon-containing particles are chemically reacted with the moiety.

22. A fuel cell catalyst layer, comprising:

carbon-containing particles; and

a moiety covalently bound to the carbon-containing particles,

wherein:

a hydrophobicity of the fuel cell catalyst layer is greater than a hydrophobicity of the carbon-containing particles;

the moiety comprises —(CH 2 ) x (CF 2 ) y Ar(αH, βX) z ;

x, y, and z are each independently an integer from 0-10, wherein x, y, and z are each greater than zero;

Ar(αH, βX) is an aromatic ring with α hydrogen atoms and βhalogen atoms; and

Ar(αH, βX) comprises a moiety selected from the group consisting of —C 6 F 5 , —C 6 F 4 H, —C 6 F 3 H 2 , —C 6 F 2 H 3 , and —C 6 FH 4 .

23. The fuel cell catalyst layer of claim 22 , wherein the carbon-containing particles are in the form of a sheet.

24. The fuel cell catalyst layer of claim 22 , wherein the moiety is selected from the group consisting of aromatic moieties, halogens, hydrocarbon moieties, and combinations thereof.

25. The fuel cell catalyst layer of claim 22 , wherein the fuel cell catalyst layer comprises a catalyst.

26. The fuel cell catalyst layer of claim 25 , wherein the catalyst is supported by the carbon-containing particles.

27. The fuel cell catalyst layer of claim 25 , wherein the fuel cell catalyst layer comprises from about one weight percent to about 50 weight percent of the catalyst.

28. The fuel cell catalyst layer of claim 25 , wherein the catalyst comprises platinum.

29. The fuel cell catalyst layer of claim 22 , further comprising a proton conducting material.

30. The fuel cell catalyst layer of claim 29 , wherein the fuel cell catalyst layer comprises from about five weight percent to about 45 weight percent of the proton conducting material.

31. The fuel cell catalyst layer of claim 29 , wherein the proton conducting material comprises a perfluorinated ionomer.

32. A fuel cell system, comprising:

a first fuel cell flow plate;

a second fuel cell flow plate;

an electrolyte between the first and second fuel cell flow plates;

a fuel cell catalyst layer between the first fuel cell flow plate and the electrolyte, the fuel cell catalyst layer comprising:

carbon-containing particles; and

a moiety covalently bound to the carbon-containing particles,

wherein:

a hydrophobicity of the fuel cell catalyst layer is greater than a hydrophobicity of the carbon-containing particles;

the moiety comprises —(CH 2 ) x (CF 2 ) y Ar(αH,βX) z ;

x, y, and z are each independently an integer from 0-10, wherein x, y, and z are each greater than zero;

Ar(αH, βX) is an aromatic ring with α hydrogen atoms and β halogen atoms; and

Ar(αH, βX) comprises a moiety selected from the group consisting of —C 6 F 5 , —C 6 F 4 H, —C 6 F 3 H 2 , —C 6 F 2 H 3 , and —C 6 FH 4 .

33. A method of making a fuel cell catalyst layer, the method comprising:

covalently bonding carbon-containing particles with a moiety to provide the fuel cell catalyst layer,

wherein:

the fuel cell catalyst layer has a hydrophobicity greater than a hydrophobicity of the carbon-containing particles;

the moiety comprises —(CH 2 ) x (CF 2 ) y Ar(αH,βX) z ;

x, y, and z are each independently an integer from 0-10, wherein x, y, and z are each greater than zero;

Ar(αH, βX) is an aromatic ring with α hydrogen atoms and β halogen atoms; and

Ar(αH, βX) comprises a moiety selected from the group consisting of —C 6 F 5 , —C 6 F 4 H, —C 6 F 3 H 2 , —C 6 F 2 H 3 , and —C 6 FH 4 .