Method of making tungsten-containing fuel cell catalysts
Activation of a tungsten-containing catalyst using water in a PEM-type fuel cell is described as well as cathode operation of the tungsten-containing catalyst.
1. A method of making a tungsten-containing fuel cell catalyst comprising the steps of:
(a) depositing a tungsten-containing precursor on a carbon support, wherein the carbon support has been preteated with a cationic surfactant;
(b) contacting the support with water;
(c) applying a voltage to the support sufficient to form the tungsten-containing catalyst.
2. The method of claim 1 wherein the applied voltage is about 0.5 VDC to about 30 VDC.
3. The method of claim 2 wherein the applied voltage is 4 VDC.
4. The method of claim 1 wherein the tungsten-containing precursor is ammonium tungstate, sodium tungstate, tungstic acid or a tungsten heteropoly salt.
5. The method of claim 1 wherein the tungsten-containing precursor is a tungsten heteropoly salt.
6. The method of claim 1 wherein the tungsten-containing precursor is ammonium metatungstate or sodium metatungstate.
7. The method of claim 1 wherein the carbon support is a carbon black.
8. The method of claim 1 wherein the cationic surfactant is cetylpyridinum chloride.
9. The method of claim 1 wherein the water is deionized water.
10. The method of claim 1 wherein the support is a cathode of the fuel cell.
11. A method of making a tungsten-containing fuel cell catalyst comprising the steps of:
(a) mixing a carbon black with a solution of a tungsten-containing precursor to form a dispersion, wherein the carbon black has been pretreated with a cationic surfactant;
(b) drying the dispersion to form a supported catalyst precursor;
(c) forming an electrode using the supported catalyst precursor;
(d) contacting the catalyst precursor with water; and
(e) applying a voltage to the electrode sufficient to form the tungsten-containing catalyst.
12. The method of claim 11 wherein the tungsten-containing precursor is ammonium tungstate, sodium tungstate, tungstic acid, or a tungsten heteropoly salt.
13. The method of claim 11 wherein the tungsten-containing catalyst is formed in situ in a proton-exchange membrane fuel cell.
14. The method of claim 13 wherein the electrode is a cathode of the fuel cell.
15. The method of claim 11 wherein the applied voltage is from about 0.5 VDC to about 30 VDC.
16. The method of claim 15 wherein the applied voltage is 4 VDC.
17. The method of claim 11 wherein the cationic surfactant is cetylpyridinum chloride.