Electrochemical catalysts with enhanced catalytic activity

Patent metadata

Field	Value
Publication number	US-2020127300-A1
Application number	US-201916713890-A
Country	US
Kind code	A1
Filing date	Dec 13, 2019
Priority date	Jun 13, 2017
Publication date	Apr 23, 2020
Grant date	—

Abstract

A catalyst structure includes: (1) a substrate; (2) a catalyst layer on the substrate; and (3) an adhesion layer disposed between the substrate and the catalyst layer. In some implementations, an average thickness of the adhesion layer is about 1 nm or less. In some implementations, a material of the catalyst layer at least partially extends into a region of the adhesion layer. In some implementations, the catalyst layer is characterized by a lattice strain imparted by the adhesion layer.

First claim

What is claimed is:

1 . A catalyst structure comprising:
a substrate; a catalyst layer on the substrate; and an adhesion layer disposed between the substrate and the catalyst layer, wherein an average thickness of the adhesion layer is 1 nm or less.

2 . A catalyst structure comprising:
a substrate; a catalyst layer on the substrate; and an adhesion layer disposed between the substrate and the catalyst layer, wherein a material of the catalyst layer at least partially extends into a region of the adhesion layer.

3 . The catalyst structure of claim 2 , wherein the region includes an alloy of the material of the catalyst layer and a material of the adhesion layer.

4 . A catalyst structure comprising:
a substrate; a catalyst layer on the substrate; and an adhesion layer disposed between the substrate and the catalyst layer, wherein the catalyst layer is characterized by a lattice strain imparted by the adhesion layer.

5 . The catalyst structure of claim 4 , wherein the adhesion layer includes a crystalline phase.

6 . The catalyst structure of any one of claims 1 , 2 , and 4 , wherein the adhesion layer includes at least one of a metal oxide or a metalloid oxide.

7 . A catalyst structure comprising:
a substrate; and a catalyst layer on the substrate, wherein the catalyst layer includes discrete regions that are spaced apart from one another, and at least one of the discrete regions includes a portion that is bonded to the substrate, and another portion that extends over the substrate and is spaced apart from the substrate by a gap.

8 . The catalyst structure of any one of claims 1 , 2 , 4 , and 7 , wherein the catalyst layer includes a platinum group metal.

9 . The catalyst structure of any one of claims 1 , 2 , 4 , and 7 , further comprising an over-layer on the catalyst layer.

10 . The catalyst structure of claim 9 , wherein an average thickness of the over-layer is 1 nm or less.

11 . The catalyst structure of claim 9 , wherein the over-layer provides partial surface coverage of the catalyst layer.

12 . The catalyst structure of claim 9 , wherein the catalyst layer includes a platinum group metal, and the over-layer includes an alloy of the platinum group metal and a material of the over-layer.

13 . A catalyst structure comprising:
a substrate; a catalyst layer on the substrate; and an over-layer on the catalyst layer.

14 . The catalyst structure of claim 13 , wherein an average thickness of the over-layer is 1 nm or less.

15 . The catalyst structure of claim 13 , wherein the over-layer provides partial surface coverage of the catalyst layer.

16 . The catalyst structure of claim 13 , wherein the catalyst layer includes a platinum group metal, and the over-layer includes at least one of a metal oxide, a metalloid oxide, a metal nitride, a metalloid nitride, a metal carbide, a metalloid carbide, a metal boride, a metalloid boride, a metal sulfide, a metalloid sulfide, a metal phosphide, a metalloid phosphide, a metal silicide, or a metalloid silicide.

17 . The catalyst structure of claim 13 , wherein a material of the catalyst layer at least partially extends into a region of the over-layer.

18 . A membrane electrode assembly for a fuel cell, comprising a polymeric ion-conductive membrane and an electrocatalyst layer adjacent to the polymeric ion-conductive membrane, wherein the electrocatalyst layer includes the catalyst structure of any one of claims 1 , 2 , 4 , 7 , and 13 .

19 . A fuel cell comprising:
a cathode electrocatalyst layer; an anode electrocatalyst layer; and a polymeric ion-conductive membrane disposed between the cathode electrocatalyst layer and the anode electrocatalyst layer, wherein at least one of the cathode electrocatalyst layer or the anode electrocatalyst layer includes the catalyst structure of any one of claims 1 , 2 , 4 , 7 , and 13 .

20 . A fuel cell comprising:
a first gas diffusion layer; a second gas diffusion layer; and a polymeric ion-conductive membrane disposed between the first gas diffusion layer and the second gas diffusion layer, wherein at least one of the first gas diffusion layer or the second gas diffusion layer includes the catalyst structure of any one of claims 1 , 2 , 4 , 7 , and 13 .

21 . A method comprising:
depositing an adhesion layer on a substrate by atomic layer deposition to yield an adhesion layer-coated substrate; and depositing a catalyst layer on the adhesion layer-coated substrate by atomic layer deposition to yield a catalyst-coated substrate.

22 . The method of claim 21 , wherein an average thickness of the adhesion layer is 1 nm or less.

23 . The method of claim 21 , further comprising intermixing the catalyst layer and the adhesion layer such that a material of the catalyst layer at least partially extends into a region of the adhesion layer.

24 . The method of claim 23 , wherein the material of the catalyst layer reacts with a material of the adhesion layer to form an alloy within the region of the adhesion layer.

25 . The method of claim 21 , further comprising introducing defects into the adhesion layer to increase an electrical conductivity of the adhesion layer.

26 . The method of claim 25 , wherein introducing the defects includes introducing oxygen vacancies into the adhesion layer.

27 . The method of claim 25 , wherein introducing the defects includes introducing dopants into the adhesion layer.

28 . The method of claim 21 , further comprising inducing a phase transformation of the adhesion layer subsequent to depositing the catalyst layer.

29 . The method of claim 28 , wherein inducing the phase transformation includes heating the adhesion layer to induce a transformation from an amorphous phase to a crystalline phase.

30 . The method of claim 21 , further comprising at least partially removing the adhesion layer subsequent to depositing the catalyst layer.

31 . The method of claim 30 , wherein at least partially removing the adhesion layer includes exposing the catalyst-coated substrate to a solution in which a material of the adhesion layer has a greater solubility relative to a material of the catalyst layer.

32 . The method of claim 21 , wherein the adhesion layer includes a ceramic.

33 . The method of claim 21 , further comprising functionalizing the substrate prior to depositing the adhesion layer.

34 . The method of claim 21 , further comprising functionalizing the adhesion layer prior to depositing the catalyst layer.

35 . The method of claim 21 , further comprising depositing an over-layer on the catalyst-coated substrate by atomic layer deposition.

36 . The method of claim 35 , wherein an average thickness of the over-layer is 1 nm or less.

37 . The method of claim 35 , wherein the over-layer provides partial surface coverage of the catalyst layer.

38 . The method of claim 35 , wherein the over-layer includes a ceramic.

39 . The method of claim 35 , further comprising functionalizing the catalyst layer prior to depositing the over-layer.

Assignees

• Univ Leland Stanford Junior
• Volkswagen Ag

Inventors

• Prinz Friedrich B
• Xu Shicheng
• Kim Yongmin
• Jaramillo Thomas
• Higgins Drew C
• Yusuf Maha
• Wang Zhaoxuan
• Lee Kate
• Orazov Marat
• Lee Dong Un
• Graf Tanja
• Schladt Thomas
• Huebner Gerold
• Wittern Hanna-Lena
• Mueller Jonathan Edward

Classifications

• H01M4/925 Primary

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

• H01M2300/0082

  Organic polymers · CPC title

• H01M4/8892

  Impregnation or coating of the catalyst layer, e.g. by an ionomer · CPC title

• H01M4/8867

  Vapour deposition · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title