# US 8,541,146 B2 · Photocatalytic methods for preparation of electrocatalyst materials

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,541,146 B2
- Document ID: US8541146B2
- Status: Granted
- Kind: B2
- Application number: 11/329,853
- Filed: 2006-01-11
- Published: 2006-11-09
- Granted: 2013-09-24
- Earliest claimed: 2005-01-12
- Assignees: Toyota Motor Engineering & Manufacturing North America, Inc.; Toyota Motor Corporation; Sandia Corporation, Operator of Sandia National Laboratories
- Applicants: Wen Li; Tetsuo Kawamura; Tetsuo Nagami; Hiroaki Takahashi; John Muldoon; John A. Shelnutt; Yujiang Song; James E. Miller; Michael A. Hickner; Craig Medforth
- Inventors: Wen Li; Tetsuo Kawamura; Tetsuo Nagami; Hiroaki Takahashi; John Muldoon; John A. Shelnutt; Yujiang Song; James E. Miller; Michael A. Hickner; Craig Medforth
- Web page: https://patentgrep.com/patent/US8541146B2

## CPC

- H01M 4/9083: {on carbon or graphite}
- H01M 4/92: Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence)
- H01M 4/926: {on carbon or graphite}
- H01M 4/921: {Alloys or mixtures with metallic elements}
- H01M 2008/1095: {Fuel cells with polymeric electrolytes}
- Y02E 60/50: Fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

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).

## Claims

### Claim 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.

### Claim 2 (depends on 1)

The method of claim 1, wherein photocatalyst is an organometallic or free base porphyrin compound.

### Claim 3 (depends on 1)

The method of claim 1, wherein the photocatalyst is a metal porphyrin.

### Claim 4 (depends on 1)

The method of claim 1, wherein the photocatalyst is a tin porphyrin.

### Claim 5 (depends on 1)

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.

### Claim 6 (depends on 1)

The method of claim 1, wherein the metal particles are platinum-containing particles.

### Claim 7 (depends on 6)

The method of claim 6, wherein the metal particles have a median diameter between 1 and 10 nm.

### Claim 8 (depends on 1)

The method of claim 1, wherein the reductant is selected from the group of reductants consisting of ascorbic acid and hydroquinone.

### Claim 9 (depends on 1)

The method of claim 1, wherein the support material comprises carbon.

### Claim 10 (depends on 1)

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.

### Claim 11 (depends on 1)

The method of claim 1, wherein illuminating the mixture comprises exposing the mixture to visible or UV light.

### Claim 12 (depends on 1)

The method of claim 1, further comprising pyrolyzing the electrocatalyst to convert organic components to additional carbon support material.