Catalyst

Patent metadata

Field	Value
Publication number	US-11955645-B2
Application number	US-201917047029-A
Country	US
Kind code	B2
Filing date	Apr 11, 2019
Priority date	Apr 13, 2018
Publication date	Apr 9, 2024
Grant date	Apr 9, 2024

Abstract

Catalysts comprising a Ta layer having an outer layer with a layer comprising Pt directly thereon, wherein the Ta 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 Ta are present in an atomic ratio in a range from 0.01:1 to 10:1. Catalyst described herein are useful, for example, in fuel cell membrane electrode assemblies.

First claim

What is claimed is:

1. An article comprising:
nanostructured elements comprising microstructured whiskers having an outer surface; and
a catalyst on the outer surface, the catalyst comprising a Ta layer having an outer layer with a layer comprising Pt directly thereon, wherein the Ta 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 Ta are present in an atomic ratio in a range from 0.01:1 to 10:1.

2. The article of claim 1 , wherein the catalyst surface area is at least 20% greater than would be present without the presence of the Ta layer.

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

4. A catalyst comprising:
a Ta layer having an outer layer with a layer comprising Pt thereon, wherein the Ta 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 Ta are present in an atomic ratio in a range from 0.01:1 to 10:1, and a layer comprising Ir is present between the Ta layer and the layer comprising Pt, and wherein the layer comprising Ir has an average thickness in a range from 0.04 to 50 nanometers.

5. The catalyst of claim 4 , wherein the Ta to Ir atomic ratio is in a range from 0.01:1 to 100:1.

6. The article of claim 1 , wherein the layer comprising Pt comprises Pt crystallites with an FCC lattice constant in a range from 0.395 to 0.392 nm.

7. The article of claim 1 , wherein the layer comprising Pt comprises Pt crystallites with a crystallite size in a range from 2 to 20 nanometers.

8. The article of claim 1 , wherein the layer comprising Pt further comprises Ni.

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

10. A method of making the catalyst of claim 4 , the method comprising depositing the Ta layer, the layer of Ir, the layer comprising Pt, or combinations thereof 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.

11. The article of claim 1 , wherein the Ta layer is directly on the microstructured whiskers.

12. The article of claim 1 , wherein the microstructured whiskers are attached to a backing.

13. A method of making the article of claim 1 , the method comprising depositing the Ta layer, the layer comprising Pt, or both 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.

14. The method of claim 13 , further comprising annealing at least one of the Ta layer or the layer comprising Pt.

15. The catalyst of claim 4 , wherein the layer comprising Pt comprises Pt crystallites with an FCC lattice constant in a range from 0.395 to 0.392 nm.

16. The catalyst of claim 4 , wherein the layer comprising Pt comprises Pt crystallites with a crystallite size in a range from 2 to 20 nanometers.

17. The catalyst of claim 4 , wherein the layer comprising Pt further comprises Ni.

18. The catalyst of claim 17 , wherein the Pt to Ni atomic ratio is in a range from 0.5:1 to 5:1.

Assignees

• 3M Innovative Properties Company

Inventors

• Steinbach Andrew J L
• Haug Andrew T
• Lewinski Krzysztof A
• Hester Amy E
• Thoma Grant M
• Bedoya Cedric
• Zeng Zhenhua
• Greeley Jeffrey P

Classifications

• H01M4/9041 Primary

  Metals or alloys (H01M4/92 takes precedence) · CPC title

• H01M4/8657

  layered · CPC title

• H01M4/9058 Primary

  of noble metals or noble-metal based alloys · CPC title

• H01M4/92

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title

• H01M4/921

  Alloys or mixtures with metallic elements · CPC title