In one aspect, the invention features a method including sorbing carbon monoxide to a catalyst layer of a fuel cell, and oxidizing the carbon monoxide. The method can be used to pre-condition or activate the catalyst layer.
1. A method, comprising:
sorbing carbon monoxide to a catalyst layer of a fuel cell; and
oxidizing the carbon monoxide,
wherein the sorbing and oxidizing are performed before the fuel cell is operated.
2. The method of claim 1 , further comprising, during sorption of carbon monoxide, maintaining the potential of the catalyst layer at a first potential less than the oxidation potential of carbon monoxide.
3. The method of claim 2 , wherein the first potential is from about 0.2 to about 0.5V versus a standard hydrogen electrode.
4. The method of claim 1 , comprising electrochemically oxidizing the carbon monoxide.
5. The method of claim 4 , comprising scanning the potential of the catalyst layer.
6. The method of claim 1 , comprising chemically oxidizing the carbon monoxide.
7. The method of claim 6 , wherein chemically oxidizing the carbon monoxide comprises contacting the catalyst layer with oxygen or water.
8. The method of claim 1 , further comprising, after oxidizing the carbon monoxide, sorbing carbon monoxide to the catalyst layer, and oxidizing the carbon monoxide.
9. The method of claim 1 , further comprising incorporating the fuel cell into a fuel cell stack.
10. The method of claim 1 , wherein the fuel cell is a part of a fuel cell stack.
11. The method of claim 1 , further comprising contacting the catalyst layer with a fuel.
12. The method of claim 11 , wherein the fuel comprises hydrogen or methanol.
13. The method of claim 1 , further comprising contacting the catalyst layer with an oxidant.
14. The method of claim 1 , wherein the fuel cell comprises a proton-exchange membrane.
15. A method, comprising:
sorbing a first material other than a fuel to a catalyst layer of a fuel cell; and
oxidizing the first material from the catalyst layer,
wherein the sorbing and oxidizing are performed before the fuel cell is operated.
16. The method of claim 15 , wherein the first material comprises carbon monoxide.
17. The method of claim 15 , comprising electrochemically oxidizing the first material.
18. The method of claim 15 , further comprising repeating the sorbing and oxidizing of the first material.
19. The method of claim 15 , further comprising incorporating the fuel cell into a fuel cell system.
20. The method of claim 15 , wherein the fuel cell is a part of a fuel cell stack.
21. A method, comprising:
operating a fuel cell;
turning the fuel cell off;
after the turning the fuel cell off, sorbing carbon monoxide to a catalyst layer of the fuel cell; and
after sorbing the carbon monoxide, oxidizing the carbon monoxide,
wherein the sorbing and oxidizing are performed when the fuel cell is not operating.
22. A method, comprising:
operating a fuel cell;
turning the fuel cell off;
after turning the fuel cell off, sorbing a first material other than a fuel to a catalyst layer of a fuel cell; and
after sorbing the first material, oxidizing the first material from the catalyst layer,
wherein the sorbing and oxidizing are performed when the fuel cell is not operating.