Fuel cell electrodes
A process includes patterning a surface of a platinum group metal-based electrode by contacting the electrode with an adsorbate to form a patterned platinum group metal-based electrode including platinum group metal sites blocked with adsorbate molecules and platinum group metal sites which are not blocked.
1. A process comprising:
patterning a surface of a platinum group metal-based electrode by contacting the electrode with an adsorbate and electrochemically cycling the electrode in an oxygen saturated solution to form a patterned platinum group metal-based electrode comprising platinum group metal sites blocked with adsorbate molecules and platinum group metal sites which are not blocked.
2. The process of claim 1 , wherein the platinum group metal-based electrode comprises Pt, Pd, Ir, or Rh, or a Pt alloy with one or more of Co, Ni, Fe, Ti, Cr, V, or Mn.
3. The process of claim 1 , wherein the platinum group metal-based electrode comprises Pt(100), Pt(111), Pt(1099), or polycrystalline Pt.
4. The process of claim 1 , wherein the adsorbate comprises cyanide.
5. The process of claim 1 , wherein the patterning comprises heating the platinum group metal-based electrode to an annealing temperature from about 500 K to about 1500 K under a reducing atmosphere, cooling the electrode, and immersing the electrode in a solution comprising the adsorbate.
6. The process of claim 5 , wherein the annealing temperature is from about 1000 K to about 1200 K.
7. The process of claim 5 , wherein the reducing atmosphere comprises hydrogen gas.
8. The process of claim 5 , wherein the reducing atmosphere comprises hydrogen gas and an inert gas.
9. The process of claim 8 , wherein the inert gas comprises He, Ne, Ar, or N 2 .
10. The process of claim 5 , wherein the electrode is cooled to about ambient temperature.
11. The process of claim 5 , wherein the solution comprises an aqueous solution of a cyanide.
12. The process of claim 11 , wherein the cyanide comprises HCN, NaCN or KCN.
13. The process of claim 11 , wherein a concentration of the cyanide in the aqueous solution is from about 0.01 M to about 2 M.
14. The process of claim 4 , wherein from about 25% to about 40% of the platinum group metal sites are blocked by cyanide and from about 60% to about 75% of the platinum group metal sites are not blocked by cyanide.
15. The process of claim 5 , wherein the solution comprises a solvent and the adsorbate.
16. A platinum group metal-based electrode produced by the process of claim 1 .
17. A platinum group metal-based electrode of claim 16 which comprises Pt(100), Pt(111), Pt(1099), or polycrystalline Pt.
18. A fuel cell comprising the electrode of claim 16 .
19. The process of claim 1 , wherein the electrochemical cycling is performed at least 5 times.
20. The process of claim 1 , wherein the electrochemical cycling is performed from about 0.07 V to about 1.05 V.