Nanostructured PtxMy catalyst for PEMFC cells having a high activity and a moderate H2O2 production

Patent metadata

Field	Value
Publication number	US-9608276-B2
Application number	US-201414162032-A
Country	US
Kind code	B2
Filing date	Jan 23, 2014
Priority date	Aug 1, 2011
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A method of manufacturing a catalyst for a Pt x M y -based PEMFC, M being a transition metal, including the steps of: depositing Pt x M y nanostructures on a support; annealing the nanostructures; depositing a Pt x M y layer at the surface of the nanostructures thus formed; and chemically leaching metal M. It also aims at the catalyst obtained with this method.

First claim

The invention claimed is:

1. A method of manufacturing a catalyst for a Pt x M y -based PEMFC, M being a transition metal, comprising the steps of:
depositing a first layer of Pt x M y nanostructures on a support;
annealing the nanostructures;
depositing a second Pt x M y layer at the surface of the nanostructures thus formed; and
producing structured vacancies or cavities, having a size which does not exceed 6 Angströms, at the surface of the second Pt x M y layer, by controlled chemical leaching of metal M.

2. The method of manufacturing a catalyst for a PEMFC of claim 1 , wherein the support is a gas diffusion layer of the PEMFC.

3. The method of manufacturing a catalyst for a PEMFC of claim 2 , wherein the gas diffusion layer has a thickness of 200 micrometers.

4. The method of manufacturing a catalyst for a PEMFC of claim 1 , wherein the support is not a gas diffusion layer of the PEMFC, and wherein after annealing, the nanostructures are transferred onto the gas diffusion layer of the PEMFC.

5. The method of manufacturing a catalyst for a PEMFC of claim 1 , wherein metal M is selected from the group consisting of Ni, Fe, Co, and Cr.

6. The method of manufacturing a catalyst for a PEMFC of claim 5 , wherein the catalyst is formed with Pt 3 Ni.

7. The method of manufacturing a catalyst for a PEMFC of claim 1 , wherein the deposition of nanostructures is performed by cathode sputtering.

8. The method of manufacturing a catalyst for a PEMFC of claim 1 , wherein the anneal is performed at a temperature in a range of 600° C. to 1,200° C.

9. The method of manufacturing a catalyst for a PEMFC of claim 8 , wherein the anneal is performed for a 1-hour duration.

10. The method of manufacturing a catalyst for a PEMFC of claim 1 , wherein the deposition of the Pt x M y layer is performed by MOCVD.

11. The method of manufacturing a catalyst for a PEMFC of claim 10 , wherein the MOCVD is performed by means of organometallic precursors of platinum and of the metal.

12. The method of manufacturing a catalyst for a PEMFC of claim 11 , wherein the MOCVD is performed at a temperature in a range of 200° C. to 400° C.

13. The method of manufacturing a catalyst for a PEMFC of claim 12 , wherein the MOCVD is performed at a temperature of 300° C.

14. The method of manufacturing a catalyst for a PEMFC of claim 1 , wherein the chemical leaching of metal M is performed by immersion in a liquid electrolyte.

15. The method of manufacturing a catalyst for a PEMFC of claim 14 , wherein the liquid electrolyte is H 2 SO 4 .

16. The method of manufacturing a catalyst for a PEMFC of claim 14 , wherein the chemical leaching is performed for 1 hour.

17. A catalyst capable of being obtained by means of the method of claim 1 , said catalyst comprising core/shell nanostructures made of Pt x M y covered with a Pt x M y layer comprising vacancies.

18. The catalyst of claim 17 , wherein the vacancies have a size in the range from 2 to 6 Angströms.

19. A PEMFC-type fuel cell comprising at least at one of its electrodes the catalyst of claim 17 .

20. A method of improving the lifetime of a PEMFC-type fuel cell comprising using as a catalyst, at least at its cathode, the catalyst of claim 17 .

21. A PEMFC-type fuel cell comprising as its cathode the catalyst of claim 17 .

Assignees

• Commissariat Energie Atomique

Inventors

• Franco Alejandro
• Ferreira De Morais Rodrigo
• Loffreda David
• Sautet Philippe

Classifications

• H01M4/8814

  Temporary supports, e.g. decal · CPC title

• H01M4/8867

  Vapour deposition · CPC title

• H01M2004/8689

  Positive electrodes · CPC title

• H01M4/8657 Primary

  layered · CPC title

• H01M4/925

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