Catalyst for a fuel cell

Patent metadata

Field	Value
Publication number	US-2022181643-A1
Application number	US-202017310628-A
Country	US
Kind code	A1
Filing date	Mar 20, 2020
Priority date	Mar 22, 2019
Publication date	Jun 9, 2022
Grant date	—

Abstract

The present invention provides a process for preparing a catalyst precursor, said process comprising the steps of (i) providing PtaXb alloy particles on a support material and (ii) applying a shell of X to the PtaXb alloy particles to provide a catalyst precursor comprising particles having a PtaXb core and an X shell. The ratio of a to b is in the range of and including 10:1 to 1:2.5 and X is Co, Ni, Y, Gd, Sc or Cu. Also provided is a process for preparing a catalyst material.

First claim

1 : A process for preparing a catalyst precursor, said process comprising the steps of:
(i) providing Pt a X b alloy particles on a support material; (ii) applying a shell of X to the Pt a X b alloy particles to provide a catalyst precursor comprising particles having a Pt a X b core and an X shell; wherein the ratio of a to b is in the range of and including 10:1 to 1:2.5; and wherein X is Co, Ni, Y, Gd, Sc or Cu.

2 : The process according to claim 1 , wherein step (ii) is performed by carrying out a controlled surface reaction.

3 : The process according to claim 1 , wherein X is Co, Ni or Cu.

4 : The process according to claim 1 , wherein X is Y, Gd or Sc.

5 : The process according to claim 1 , wherein the ratio of a to b is in the range of and including 5:1 to 1:2.5.

6 : A process for preparing a catalyst material, said process comprising the steps of:
(i) providing Pt a X b alloy particles on a support material; (ii) applying a shell of X to the Pt a X b alloy particles to provide a catalyst precursor comprising particles having a Pt a X b core and an X shell; then (iii) heating the catalyst precursor at a temperature of no more than 900° C.; then (iv) subjecting the material produced in step (iii) to conditions sufficient to leach a portion of metal X from the material; wherein the ratio of a to b is in the range of and including 10:1 to 1:2.5; and wherein X is Co, Ni, Y, Gd, Sc or Cu.

7 : The process according to claim 6 , wherein in step (iii) the catalyst precursor is heated at a temperature of at least 150° C.

8 : The process according to claim 6 , wherein step (ii) is performed by carrying out a controlled surface reaction.

9 : The process according claim 6 , wherein X is Co, Ni or Cu.

10 : The process according to claim 6 , wherein X is Y, Gd or Sc.

11 : The process according to claim 6 , wherein the ratio of a to b is in the range of and including 5:1 to 1:2.5.

12 : The process according to claim 6 , wherein step (iv) is carried out by acid washing.

13 : A catalyst material obtainable by the process according to claim 6 .

14 : A catalyst layer comprising a catalyst material according to claim 13 .

15 : A catalyst coated membrane comprising the catalyst layer of claim 14 and an ion-conducting membrane.

16 : A gas diffusion electrode comprising the catalyst layer of claim 14 and a gas diffusion layer.

17 : A membrane electrode assembly comprising the catalyst layer of claim 14 .

18 : A fuel cell comprising the catalyst layer of claim 14 .

19 : A membrane electrode assembly comprising the catalyst coated membrane of claim 15 .

20 : A membrane electrode assembly comprising the gas diffusion electrode of claim 16 .

21 : A fuel cell comprising the membrane electrode assembly of claim 19 .

22 : A fuel cell comprising the membrane electrode assembly of claim 20 .

Assignees

• Johnson Matthey Fuel Cells Ltd

Inventors

• Martinez-Bonastre Alejandro
• O'Malley Rachel
• Theobald Brian

Classifications

• B01J35/45

  Nanoparticles · CPC title

• H01M4/8807 Primary

  Gas diffusion layers · CPC title

• H01M4/926

  on carbon or graphite · CPC title

• H01M4/8878

  Treatment steps after deposition of the catalytic active composition or after shaping of the electrode being free-standing body · CPC title

• B01J21/18

  Carbon · CPC title