Photocatalytic methods for preparation of electrocatalyst materials
The invention relates to methods of preparing metal particles on a support material, including platinum-containing nanoparticles on a carbon support. Such materials can be used as electrocatalysts, for example as improved electrocatalysts in polymer electrolyte membrane fuel cells (PEM-FCs).
1. A method for making a supported electrocatalyst, the method comprising:
providing a mixture, the mixture including a photocatalyst, a reductant, a metal compound, and a support material;
dispersing the photocatalyst on the support material and mixing the photocatalyst and the support material with the reductant and the metal compound;
illuminating the mixture forming metal particles in situ by reduction of the metal compound on a surface of the support material forming the supported electrocatalyst in a single step wherein the metal particles have a median diameter of less than 100 nm and are evenly distributed on the support material.
2. The method of claim 1 , wherein photocatalyst is an organometallic or free base porphyrin compound.
3. The method of claim 1 , wherein the photocatalyst is a metal porphyrin.
4. The method of claim 1 , wherein the photocatalyst is a tin porphyrin.
5. The method of claim 1 , wherein the mixture includes at least one metal compound selected from a group consisting of platinum compounds, cobalt compounds, palladium compounds, iron compounds, and nickel compounds.
6. The method of claim 1 , wherein the metal particles are platinum-containing particles.
7. The method of claim 6 , wherein the metal particles have a median diameter between 1 and 10 nm.
8. The method of claim 1 , wherein the reductant is selected from the group of reductants consisting of ascorbic acid and hydroquinone.
9. The method of claim 1 , wherein the support material comprises carbon.
10. The method of claim 1 , wherein supporting the metal particles on a support material comprises combining a suspension of the metal particles with a suspension of the support material.
11. The method of claim 1 , wherein illuminating the mixture comprises exposing the mixture to visible or UV light.
12. The method of claim 1 , further comprising pyrolyzing the electrocatalyst to convert organic components to additional carbon support material.