Catalyst for proton exchange membrane fuel cell and production method for catalyst

Patent metadata

Field	Value
Publication number	US-2017149069-A1
Application number	US-201515323286-A
Country	US
Kind code	A1
Filing date	Jul 21, 2015
Priority date	Aug 5, 2014
Publication date	May 25, 2017
Grant date	—

Abstract

The present invention provides a catalyst for a solid polymer fuel cell, having excellent initial activity and good durability and a production method thereof. The present invention is a catalyst for a solid polymer fuel cell, including catalyst particles composed of platinum or a platinum alloy supported on a carbon powder carrier, the catalyst having sulfo groups (—SO 3 H) at least on the catalyst particles, and the catalyst further having a fluorine compound having a C—F bond supported at least on the catalyst particles. It is preferred in the catalyst of the present invention that sulfur content is 800 ppm or more and 5000 ppm or less based on the mass of the whole catalyst and the amount of the fluorine compound is 3 mass % or more and 24 mass % or less based on the mass of the whole catalyst.

First claim

1 . A catalyst for a solid polymer fuel cell, comprising catalyst particles composed of platinum or a platinum alloy supported on a carbon powder carrier,
wherein the catalyst has sulfo groups (—SO 3 H) at least on the catalyst particles, and the catalyst further has a fluorine compound having a C—F bond supported at least on the catalyst particles.

2 . The catalyst for a solid polymer fuel cell according to claim 1 , wherein sulfur (S) content is 800 ppm or more and 5000 ppm or less based on the mass of the whole catalyst.

3 . The catalyst for a solid polymer fuel cell according to claim 1 , wherein an amount of the fluorine compound is 3 mass % or more and 24 mass % or less based on the mass of the whole catalyst.

4 . The catalyst for a solid polymer fuel cell according to claim 1 , wherein the fluorine compound is a fluorine resin or a fluorine-based surfactant.

5 . The catalyst for a solid polymer fuel cell according to claim 1 , wherein in 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.

6 . The catalyst for a solid polymer fuel cell according to claim 1 , wherein the catalyst particles comprise any one of platinum, a platinum-cobalt alloy, a platinum-cobalt-manganese alloy, and a platinum-cobalt-magnesium alloy.

7 . The catalyst for a solid polymer fuel cell according to claim 1 , wherein a supporting density of the catalyst particles is 30% or more and 70% or less.

8 . A production method of the catalyst for a solid polymer fuel cell, the fuel cell defined in claim 1 , comprising:
(a) a step of preparing a catalyst containing platinum particles or platinum alloy particles supported on a carbon powder carrier; (b) a step of bringing the catalyst into contact with a mixed solution containing concentrated sulfuric acid and fuming sulfuric acid to support sulfo groups on the catalyst; and (c) a step of bringing the catalyst into contact with a solution containing a fluorine compound to form a water repellent layer containing the fluorine compound on the catalyst.

9 . The production method according to claim 8 , wherein the mixed solution in the step (b) has a temperature of 30° C. or higher and 110° C. or lower.

10 . The catalyst for a solid polymer fuel cell according to claim 2 , wherein an amount of the fluorine compound is 3 mass % or more and 24 mass % or less based on the mass of the whole catalyst.

11 . The catalyst for a solid polymer fuel cell according to claim 2 , wherein the fluorine compound is a fluorine resin or a fluorine-based surfactant.

12 . The catalyst for a solid polymer fuel cell according to claim 2 , wherein in 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.

13 . The catalyst for a solid polymer fuel cell according to claim 2 , wherein the catalyst particles comprise any one of platinum, a platinum-cobalt alloy, a platinum-cobalt-manganese alloy, and a platinum-cobalt-magnesium alloy.

14 . The catalyst for a solid polymer fuel cell according to claim 2 , wherein a supporting density of the catalyst particles is 30% or more and 70% or less.

15 . A production method of the catalyst for a solid polymer fuel cell, the fuel cell defined in claim 2 , comprising:
(a) a step of preparing a catalyst containing platinum particles or platinum alloy particles supported on a carbon powder carrier; (b) a step of bringing the catalyst into contact with a mixed solution containing concentrated sulfuric acid and fuming sulfuric acid to support sulfo groups on the catalyst; and (c) a step of bringing the catalyst into contact with a solution containing a fluorine compound to form a water repellent layer containing the fluorine compound on the catalyst.

16 . The production method according to claim 15 , wherein the mixed solution in the step (b) has a temperature of 30° C. or higher and 110° C. or lower.

17 . The catalyst for a solid polymer fuel cell according to claim 3 , wherein the fluorine compound is a fluorine resin or a fluorine-based surfactant.

18 . The catalyst for a solid polymer fuel cell according to claim 3 , wherein in 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.

19 . A production method of the catalyst for a solid polymer fuel cell, the fuel cell defined in claim 3 , comprising:
(a) a step of preparing a catalyst containing platinum particles or platinum alloy particles supported on a carbon powder carrier; (b) a step of bringing the catalyst into contact with a mixed solution containing concentrated sulfuric acid and fuming sulfuric acid to support sulfo groups on the catalyst; and (c) a step of bringing the catalyst into contact with a solution containing a fluorine compound to form a water repellent layer containing the fluorine compound on the catalyst.

20 . The production method according to claim 19 , wherein the mixed solution in the step (b) has a temperature of 30° C. or higher and 110° C. or lower.

Assignees

• Tanaka Precious Metal Ind

Inventors

• Ishida Minoru
• Matsutani Koichi

Classifications

• H01M8/1018

  Polymeric electrolyte materials · CPC title

• H01M4/88

  Processes of manufacture · CPC title

• H01M2004/8689

  Positive electrodes · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M4/926 Primary

  on carbon or graphite · CPC title