Catalyst

Patent metadata

Field	Value
Publication number	US-2021408555-A1
Application number	US-201915733735-A
Country	US
Kind code	A1
Filing date	Apr 11, 2019
Priority date	Apr 13, 2018
Publication date	Dec 30, 2021
Grant date	—

Abstract

Catalyst comprising an Ir layer having an outer layer with a layer comprising Pt directly thereon, wherein the Ir layer has an average thickness in a range from 0.04 to 30 nanometers, wherein the layer comprising Pt has an average thickness in a range from 0.04 to 50 nanometers, and wherein the Pt and Ir are present in an atomic ratio in a range from 0.01:1 to 10:1. Catalysts described herein are useful, for example, in fuel cell membrane electrode assemblies.

First claim

1 . A catalyst comprising an Ir layer having an outer layer with a layer comprising Pt directly thereon, wherein the Ir layer has an average thickness in a range from 0.04 to 30 nanometers, wherein the layer comprising Pt has an average thickness in a range from 0.04 to 50 nanometers, wherein the Pt and Ir are present in an atomic ratio in a range from 0.01:1 to 10:1, and wherein the catalyst further comprises nanoscopic metal crystallites extending from the surface of the catalyst.

2 . (canceled)

3 . The catalyst of either claim 1 , further comprising at least one pair of alternating layers, wherein the first alternating layer comprises Ir, and wherein the second alternating layer comprises Pt.

4 . (canceled)

5 . The catalyst of claim 1 , wherein the surface metal crystallites comprise at least 10 atomic % Ir.

6 . The catalyst of claim 1 , wherein the surface metal crystallites have a length in a range from 0.25 to 10 nanometers.

7 . The catalyst of claim 1 , wherein the surface metal crystallites have diameters in a range from 0.25 to 5 nanometers.

8 . The catalyst of any preceding claim 1 , wherein the layer comprising Pt further comprises Ni.

9 . The catalyst of claim 8 , wherein the Pt to Ni atomic ratio is in a range from 0.5:1 to 5:1.

10 . An article comprising nanostructured elements comprising microstructured whiskers having an outer surface having the catalyst of claim 1 thereon.

11 . The article of claim 10 , wherein the microstructured whiskers are attached to a backing.

12 . An article comprising the catalyst of claim 11 .

13 . The article according to claim 12 which comprises no electrically conductive carbon-based material.

14 . A method of making the catalyst of claim 1 , the method comprising depositing any of the layers via a deposition technique independently selected from the group consisting of sputtering, atomic layer deposition, metal organic chemical vapor deposition, molecular beam epitaxy, ion soft landing, thermal physical vapor deposition, vacuum deposition by electrospray ionization, and pulse laser deposition.

15 . The method of claim 14 , further comprising annealing at least one of the layers.

Assignees

• 3M Innovative Properties Co

Inventors

• Steinbach Andrew J L
• Haug Andrew T
• Lewinski Krzysztof A
• Hester Amy E
• Thoma Grant M
• Bedoya Cedric

Classifications

• H01M4/8657 Primary

  layered · CPC title

• H01M4/921 Primary

  Alloys or mixtures with metallic elements · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• B01J23/40

  of the platinum group metals · CPC title

• B01J37/341

  making use of electric or magnetic fields, wave energy or particle radiation (use of flames, plasma or lasers B01J37/349) · CPC title