Method for producing fine catalyst particle and fuel cell comprising fine catalyst particle produced by the production method

Patent metadata

Field	Value
Publication number	US-2016079607-A1
Application number	US-201314890181-A
Country	US
Kind code	A1
Filing date	May 13, 2013
Priority date	May 13, 2013
Publication date	Mar 17, 2016
Grant date	—

Abstract

Disclosed is a method for producing a fine catalyst particle comprising a palladium-containing particle and a platinum outermost layer covering the palladium-containing particle, wherein a first composite body containing palladium and platinum is formed by mixing the palladium-containing particle with a first solution in which a platinum compound is dissolved, and then covering at least part of a surface of the palladium-containing particle with platinum; wherein a second composite body containing palladium, platinum and copper is formed by mixing the first composite body with a second solution in which a copper compound is dissolved, and then covering at least part of a surface of the first composite body with copper using copper underpotential deposition; and wherein the copper in the second composite body is substituted with platinum derived from a third solution in which a platinum compound is dissolved.

First claim

1 - 6 . (canceled)

7 . A method for producing a fine catalyst particle comprising a palladium-containing particle and a platinum outermost layer covering the palladium-containing particle,
wherein a first composite body containing palladium and platinum is formed by mixing the palladium-containing particle with a first solution in which a platinum compound is dissolved, and, as a result of bringing the palladium-containing particle into direct contact with the first solution, then covering at least part of a surface of the palladium-containing particle with platinum; wherein a second composite body containing palladium, platinum and copper is formed by mixing the first composite body with a second solution in which a copper compound is dissolved, and then covering at least part of a surface of the first composite body with copper using copper underpotential deposition; wherein the copper in the second composite body is substituted with platinum derived from a third solution in which a platinum compound is dissolved, by mixing the second composite body with the third solution; and wherein an amount of platinum atoms contained in the first solution is 70 atm % or less, when a minimum amount of platinum atoms required to cover the palladium-containing particle with a monatomic layer of platinum is 100 atm %.

8 . The method for producing the fine catalyst particle according to claim 7 , wherein the palladium-containing particle is supported on a carrier.

9 . The method for producing the fine catalyst particle according to claim 7 , wherein the palladium-containing particle is subjected to an acid treatment in advance, before the first composite body or the composite body A is formed.

10 . The method for producing the fine catalyst particle according to claim 8 , wherein the palladium-containing particle is subjected to an acid treatment in advance, before the first composite body or the composite body A is formed.

11 . A fuel cell comprising unit cells, each of which comprises a membrane electrode assembly in which an anode electrode comprising at least an anode catalyst layer is disposed on one side of a polyelectrolyte membrane and a cathode electrode comprising at least a cathode catalyst layer is disposed on another side of the polyelectrolyte membrane,
wherein a fine catalyst particle produced by the production method defined by claim 7 is contained in at least any one of the anode catalyst layer and the cathode catalyst layer.

12 . A fuel cell comprising unit cells, each of which comprises a membrane electrode assembly in which an anode electrode comprising at least an anode catalyst layer is disposed on one side of a polyelectrolyte membrane and a cathode electrode comprising at least a cathode catalyst layer is disposed on another side of the polyelectrolyte membrane,
wherein a fine catalyst particle produced by the production method defined by claim 8 is contained in at least any one of the anode catalyst layer and the cathode catalyst layer.

13 . A fuel cell comprising unit cells, each of which comprises a membrane electrode assembly in which an anode electrode comprising at least an anode catalyst layer is disposed on one side of a polyelectrolyte membrane and a cathode electrode comprising at least a cathode catalyst layer is disposed on another side of the polyelectrolyte membrane,
wherein a fine catalyst particle produced by the production method defined by claim 9 is contained in at least any one of the anode catalyst layer and the cathode catalyst layer.

14 . A fuel cell comprising unit cells, each of which comprises a membrane electrode assembly in which an anode electrode comprising at least an anode catalyst layer is disposed on one side of a polyelectrolyte membrane and a cathode electrode comprising at least a cathode catalyst layer is disposed on another side of the polyelectrolyte membrane,
wherein a fine catalyst particle produced by the production method defined by claim 10 is contained in at least any one of the anode catalyst layer and the cathode catalyst layer.

15 . A method for producing a fine catalyst particle comprising a palladium-containing particle and a platinum outermost layer covering the palladium-containing particle,
wherein a composite body A containing palladium and copper is formed by mixing the palladium-containing particle with a second solution in which a copper compound is dissolved, and then covering at least part of a surface of the palladium-containing particle with copper using copper underpotential deposition; wherein a composite body B containing palladium and platinum is formed by mixing the composite body A with a third solution in which a platinum compound is dissolved, and then substituting the copper in the composite body A with the platinum derived from the third solution; wherein at least part of a surface of the composite body B is covered with platinum by mixing the composite body B with, in place of the third solution, a first solution in which a platinum compound is dissolved, and, as a result, bringing the composite body B into direct contact with the first solution; and wherein an amount of platinum atoms contained in the first solution is 70 atm % or less, when a minimum amount of platinum atoms required to cover the palladium-containing particle with a monatomic layer of platinum is 100 atm %.

16 . The method for producing the fine catalyst particle according to claim 15 , wherein the palladium-containing particle is supported on a carrier.

17 . The method for producing the fine catalyst particle according to claim 15 , wherein the palladium-containing particle is subjected to an acid treatment in advance, before the first composite body or the composite body A is formed.

18 . The method for producing the fine catalyst particle according to claim 16 , wherein the palladium-containing particle is subjected to an acid treatment in advance, before the first composite body or the composite body A is formed.

19 . A fuel cell comprising unit cells, each of which comprises a membrane electrode assembly in which an anode electrode comprising at least an anode catalyst layer is disposed on one side of a polyelectrolyte membrane and a cathode electrode comprising at least a cathode catalyst layer is disposed on another side of the polyelectrolyte membrane,
wherein a fine catalyst particle produced by the production method defined by claim 15 is contained in at least any one of the anode catalyst layer and the cathode catalyst layer.

20 . A fuel cell comprising unit cells, each of which comprises a membrane electrode assembly in which an anode electrode comprising at least an anode catalyst layer is disposed on one side of a polyelectrolyte membrane and a cathode electrode comprising at least a cathode catalyst layer is disposed on another side of the polyelectrolyte membrane,
wherein a fine catalyst particle produced by the production method defined by claim 16 is contained in at least any one of the anode catalyst layer and the cathode catalyst layer.

21 . A fuel cell comprising unit cells, each of which comprises a membrane electrode assembly in which an anode electrode comprising at least an anode catalyst layer is disposed on one side of a polyelectrolyte membrane and a cathode electrode comprising at least a cathode catalyst layer is disposed on another side of the polyelectrolyte membrane,
wherein a fine catalyst particle produced by the production method defined by claim 17 is contained in at least any one of the anode catalyst layer and the cathode catalyst layer.

22 . A fuel cell co

Assignees

• Toyota Motor Co Ltd

Inventors

• Kaneko Keiichi
• Fujisawa Tsugio
• Kitao Noriyuki
• Adachi Makoto

Classifications

• H01M4/8657

  layered · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M4/925 Primary

  supported on carriers, e.g. powder carriers · CPC title

• H01M4/88

  Processes of manufacture · CPC title

• H01M4/9041

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