Pt—Ni—Ir catalyst for fuel cell

Patent metadata

Field	Value
Publication number	US-11936050-B2
Application number	US-202117645072-A
Country	US
Kind code	B2
Filing date	Dec 20, 2021
Priority date	Oct 26, 2016
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

Nanoporous oxygen reduction catalyst material comprising PtNiIr. The nanoporous oxygen reduction catalyst material is useful, for example, in fuel cell membrane electrode assemblies.

First claim

What is claimed is:

1. A nanoporous oxygen reduction catalyst material comprising Pt x Ni y Ir z , where x is in a range from 26.6 to 47.8, y is in a range from 48.7 to 70, and z is in a range from 1 to 11.4,
wherein the nanoporous oxygen reduction catalyst material has at least one nanoporous layer comprising platinum and nickel,
wherein there is a layer comprising iridium on at least one of the nanoporous layers comprising platinum and nickel, and
wherein the nanoporous oxygen reduction catalyst material has an exposed iridium surface layer.

2. The nanoporous oxygen reduction catalyst material of claim 1 having pores with diameters in a range from 1 nm to 10 nm.

3. The nanoporous oxygen reduction catalyst material of claim 1 , wherein x is in a range from 26.6 to 47.6, y is in a range from 48.7 to 69.3, and z is in a range from 1 to 11.4.

4. The nanoporous oxygen reduction catalyst material of claim 1 , wherein the layer comprising iridium has a planar equivalent thickness up to 50 nm.

5. The nanoporous oxygen reduction catalyst material of claim 1 , wherein a weight ratio of platinum to iridium is in a range from 1:1 to 50:1.

6. A catalyst comprising nanostructured elements comprising microstructured support whiskers having an outer surface at least partially covered by the nanoporous oxygen reduction catalyst material of claim 1 .

7. A fuel cell membrane electrode assembly comprising the catalyst of claim 6 .

8. A method comprising:
providing an oxygen reduction catalyst material comprising PtNiIr, wherein there are layers comprising platinum and nickel; and
dealloying at least some layers comprising platinum and nickel to remove nickel from at least one layer to provide the nanoporous oxygen reduction catalyst material of claim 1 .

9. The method of claim 8 , further comprising annealing the oxygen reduction catalyst material before dealloying.

10. The method of claim 8 , further comprising depositing platinum and nickel from a target comprising platinum and nickel and depositing iridium from a target comprising iridium.

11. A method of making the nanoporous oxygen reduction catalyst material of claim 1 , the method comprising:
depositing platinum and nickel from a target comprising platinum and nickel to provide at least one layer comprising platinum and nickel;
depositing a layer comprising iridium from a target comprising iridium on at least the outermost layer of the at least one layer comprising platinum and nickel; and
dealloying the outermost layer of the at least one layer comprising platinum and nickel to remove nickel from the layer.

12. The method of claim 11 , further comprising annealing the layered material before dealloying.

Assignees

• 3M Innovative Properties Company

Inventors

• Steinbach Andrew J L
• Hester Amy E
• Van Der Vliet Dennis F

Classifications

• H01M4/921 Primary

  Alloys or mixtures with metallic elements · CPC title

• B01J23/892

  Nickel and noble metals · CPC title

• H01M4/8605

  Porous electrodes · CPC title

• H01M4/8871

  Sputtering · 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