Co-tolerant catalyst for PAFC

Patent metadata

Field	Value
Publication number	US-9887428-B2
Application number	US-201414765349-A
Country	US
Kind code	B2
Filing date	Jan 29, 2014
Priority date	Feb 5, 2013
Publication date	Feb 6, 2018
Grant date	Feb 6, 2018

Abstract

A binary alloy catalyst comprising platinum and tantalum, wherein the tantalum is present in the alloy at 15 to 50 atomic % and a phosphoric acid fuel cell comprising such a catalyst is disclosed. The catalyst provides a better CO tolerance.

First claim

The invention claimed is:

1. A catalyst comprising a binary alloy comprising platinum and tantalum, wherein the tantalum is present in the binary alloy at 15 to 50 atomic % and a high surface area conductive carbon support material, wherein the binary alloy is dispersed on the support material at a loading of 5-15 wt % based on the weight of platinum versus the total weight of the catalyst.

2. An electrode comprising the catalyst according to claim 1 .

3. An electrode according to claim 2 , wherein the electrode is the anode.

4. A phosphoric acid fuel cell comprising an electrode according to claim 2 .

5. A phosphoric acid fuel cell comprising an anode according to claim 3 , a cathode and a phosphoric acid electrolyte disposed between the anode and cathode, and wherein the anode of the fuel cell, when in operation, is supplied with a carbon monoxide-containing hydrogen fuel.

6. A phosphoric acid fuel cell according to claim 5 , in which the electrolyte is liquid phosphoric acid held in a supporting matrix.

7. A phosphoric acid fuel cell according to claim 5 , in which the electrolyte is a phosphoric acid-doped polybenzimidazole membrane.

8. A process for operating a phosphoric acid fuel cell, the process comprising: providing a phosphoric acid fuel cell, comprising an anode, wherein the anode comprises a catalyst according to claim 1 ; providing a fuel stream to the anode wherein the fuel stream comprises carbon monoxide; and operating the fuel cell at elevated temperature.

9. The process according to claim 8 , wherein the fuel stream comprises up to 4% carbon monoxide.

10. The process according to claim 8 , wherein the fuel stream comprises at least 0.5% carbon monoxide.

11. The process according to claim 8 , wherein the fuel cell is operated at a temperature equal to or greater than about 120° C.

12. The catalyst according to claim 1 , wherein the high surface area conductive carbon support material is selected from the group consisting of oil furnace black, extra-conductive black, acetylene black, heat-treated acetylene black, graphitised acetylene black, carbon nanofibres and carbon nanotubes.

Assignees

• Johnson Matthey Fuel Cells Ltd

Inventors

• Ball Sarah Caroline
• Theobald Brian Ronald Charles
• Buche Silvain

Classifications

• B01J23/6486 Primary

  Tantalum · CPC title

• H01M8/086

  Phosphoric acid fuel cells [PAFC] · CPC title

• B01J35/0033

  Operations & Transport · mapped topic

• H01M4/928

  Unsupported catalytic particles; loose particulate catalytic materials, e.g. in fluidised state · CPC title

• H01M2004/8684

  Negative electrodes · CPC title