US 12,456,738 B2
Catalyst for a fuel cell
Alejandro Martinez-Bonastre, Reading (GB); Rachel O'Malley, Reading (GB); and Brian Theobald, Reading (GB)
Assigned to Johnson Matthey Hydrogen Technologies Limited, London (GB)
Appl. No. 17/310,628
Filed by Johnson Matthey Hydrogen Technologies Limited, London (GB)
PCT Filed Mar. 20, 2020, PCT No. PCT/GB2020/050743
§ 371(c)(1), (2) Date Aug. 13, 2021,
PCT Pub. No. WO2020/193958, PCT Pub. Date Oct. 1, 2020.
Claims priority of application No. 1903950 (GB), filed on Mar. 22, 2019.
Prior Publication US 2022/0181643 A1, Jun. 9, 2022
Int. Cl. H01M 4/92 (2006.01); B01J 35/45 (2024.01); H01M 4/88 (2006.01)
CPC H01M 4/921 (2013.01) [B01J 35/45 (2024.01); H01M 4/8807 (2013.01); H01M 4/926 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A process for preparing a catalyst material, said process comprising the steps of:
(i) providing PtaXb alloy particles on a support material;
(ii) applying a shell of X to the PtaXb alloy particles to provide a catalyst precursor comprising particles having a PtaXb core and a shell of metal X atoms; then
(iii) heating the catalyst precursor at a temperature of no more than 900° C., whereby the heating causes the shell to diffuse into the core; then
(iv) subjecting the heated catalyst precursor produced in step (iii) to conditions sufficient to leach a portion of metal X therefrom;
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.