Catalyst for solid polymer fuel cells and method for producing same

Patent metadata

Field	Value
Publication number	US-2016190602-A1
Application number	US-201414908595-A
Country	US
Kind code	A1
Filing date	Aug 1, 2014
Priority date	Aug 8, 2013
Publication date	Jun 30, 2016
Grant date	—

Abstract

The present invention aims to provide a catalyst that makes it possible to reduce an amount of solid electrolyte mixed and improve initial performance of a fuel cell, and also a method for producing the catalyst. The present invention relates to a catalyst for a solid polymer fuel cell, which has sulfo groups (—SO 3 H) on catalyst particles. In TEM-EDX analysis, a ratio (I S /I Pt ) of a sulfur peak intensity (I S ) to a platinum peak intensity (I Pt ) on the catalyst particles is within a range of 0.0044 or more and 0.0090 or less. The catalyst makes it possible to reduce the amount of solid electrolyte added and also a fuel cell with excellent initial performance, and thus contributes to a practical use of a fuel cell.

First claim

1 . A catalyst for a solid polymer fuel cell, comprising catalyst particles containing platinum and cobalt supported on a carbon powder carrier,
the catalyst having sulfo groups (—SO 3 H) at least on the catalyst particles, in TEM-EDX analysis, a ratio (I S /I Pt ) of a sulfur peak intensity (I S ) to a platinum peak intensity (Ip t ) on the catalyst particles being within a range of 0.0044 or more and 0.0090 or less.

2 . The catalyst for a solid polymer fuel cell according to claim 1 , wherein
the catalyst has sulfo groups on the catalyst particles and on a carbon powder carrier, and, on the catalyst particles and on the carbon powder carrier, appearance rates of sulfur peaks based on results of TEM-EDX analysis at five or more measurement points (the number of sulfur peaks appeared/the total number of measurements×100) are 55% or more on the catalyst particles (X PtCo ) and 30% or less on the carbon powder carrier (X C ), respectively.

3 . The catalyst for a solid polymer fuel cell according to claim 2 , wherein a ratio (X PtCo /X C ) of the appearance rate of sulfur peaks on the catalyst particles (X PtCo ) to the appearance rate of sulfur peaks on the carbon powder carrier (X C ) is 2.5 or more.

4 . A method for producing a catalyst for a solid polymer fuel cell defined in claim 1 , wherein the method comprises a step of immersing a catalyst including catalyst particles containing platinum and cobalt supported on a carbon powder carrier in a mixed solution containing concentrated sulfuric acid and fuming sulfuric acid, and a temperature of the mixed solution is 40° C. or higher and 90° C. or lower.

5 . A method for producing a catalyst for a solid polymer fuel cell defined in claim 2 , wherein the method comprises a step of immersing a catalyst including catalyst particles containing platinum and cobalt supported on a carbon powder carrier in a mixed solution containing concentrated sulfuric acid and fuming sulfuric acid, and a temperature of the mixed solution is 40° C. or higher and 90° C. or lower.

6 . A method for producing a catalyst for a solid polymer fuel cell defined in claim 3 , wherein the method comprises a step of immersing a catalyst including catalyst particles containing platinum and cobalt supported on a carbon powder carrier in a mixed solution containing concentrated sulfuric acid and fuming sulfuric acid, and a temperature of the mixed solution is 40° C. or higher and 90° C. or lower.

Assignees

• Tanaka Precious Metal Ind

Inventors

• Ishida Minoru
• Matsutani Koichi

Classifications

• B01J23/8913

  Cobalt and noble metals · CPC title

• B01J27/02

  Sulfur, selenium or tellurium; Compounds thereof · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M4/923

  Compounds thereof with non-metallic elements · CPC title

• H01M4/9041

  Metals or alloys (H01M4/92 takes precedence) · CPC title