Core-shell catalysts and method for producing the same

Patent metadata

Field	Value
Publication number	US-2016218372-A1
Application number	US-201414914515-A
Country	US
Kind code	A1
Filing date	Jul 7, 2014
Priority date	Aug 30, 2013
Publication date	Jul 28, 2016
Grant date	—

Abstract

The present invention is to provide core-shell catalysts which are configured to be able to increase the performance of a unit cell of a fuel cell, and a method for producing the core-shell catalysts. Disclosed are core-shell catalysts and method for producing the same, the core-shell catalysts comprising a core containing palladium and a shell containing platinum and covering the core, wherein, in a number-based particle size frequency distribution, an average particle size is 4.70 nm or less; a standard deviation is 2.00 nm or less; and a frequency of a particle size of 5.00 nm or less is 55% or more.

First claim

1 . Core-shell catalysts comprising a core containing palladium and a shell containing platinum and covering the core,
wherein, in a number-based particle size frequency distribution, an average particle size is 4.40 nm or less; a standard deviation is 2.00 nm or less; and a frequency of a particle size of 5.00 nm or less is 71% or more.

2 . (canceled)

3 . (canceled)

4 . The core-shell catalysts according to claim 1 , wherein the standard deviation is 1.60 nm or less.

5 . The core-shell catalysts according to claim 1 , wherein an average thickness of the shells is 0.20 to 0.35 nm.

6 . A method for producing the core-shell catalysts defined by claim 1 ,
wherein a platinum-containing shell is deposited on a surface of a palladium-containing particle in which, in a number-based particle size frequency distribution, an average particle size is 3.80 nm or less; a standard deviation is 2.00 nm or less; and a frequency of a particle size of 5.00 nm or less is 83% or more.

7 . The method for producing the core-shell catalysts defined by claim 6 , wherein an average thickness of the platinum-containing shells is 0.20 to 0.35 nm.

Assignees

• Toyota Motor Co Ltd

Inventors

• Nanba Ryoichi

Classifications

• H01M4/928 Primary

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

• H01M8/08

  Fuel cells with aqueous electrolytes · CPC title

• H01M4/8825

  Methods for deposition of the catalytic active composition · CPC title

• Y02E60/50

  Fuel cells · CPC title

• H01M4/92 Primary

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title