Catalyst laminate, membrane electrode assembly, electrochemical cell, stack, water electrolyzer, and hydrogen utilizing system

Patent metadata

Field	Value
Publication number	US-2019296380-A1
Application number	US-201916293170-A
Country	US
Kind code	A1
Filing date	Mar 5, 2019
Priority date	Mar 22, 2018
Publication date	Sep 26, 2019
Grant date	—

Abstract

A catalyst laminate includes a plurality of catalyst layers containing at least one of a noble metal and an oxide of the noble metal and at least one of a non-noble metal and an oxide of the non-noble metal, including: two or more first catalyst layers and two or more second catalyst layers. In an atomic percent of the noble metal obtained by using a line analysis by energy dispersive X-ray spectroscopy in a thickness direction of the catalyst laminate. The first catalyst layer is less than an average of a highest value and a lowest value of the atomic percent of the noble metal. The second catalyst layer has an atomic percent of the noble metal equal to or greater than the average of the highest value and the lowest value thereof. The second catalyst layer is present between the first catalyst layers.

First claim

What is claimed is:

1 . A catalyst laminate comprising a plurality of catalyst layers containing at least one of a noble metal and an oxide of the noble metal and at least one of a non-noble metal and an oxide of the non-noble metal, comprising:
two or more first catalyst layers and two or more second catalyst layers, wherein in an atomic percent of the noble metal obtained by using a line analysis by energy dispersive X-ray spectroscopy in a thickness direction of the catalyst laminate, the first catalyst layer is less than an average of a highest value and a lowest value of the atomic percent of the noble metal, the second catalyst layer has an atomic percent of the noble metal equal to or greater than the average of the highest value and the lowest value thereof, and the second catalyst layer is present between the first catalyst layers.

2 . The catalyst laminate according to claim 1 , wherein when a value obtained by dividing an atomic percent of the non-noble metal of the first catalyst layer by an atomic fraction of the noble metal of the first catalyst layer is Rm (A1) and a value obtained by dividing the atomic percent of the non-noble metal of the second catalyst layer by the atomic fraction of the noble metal of the second catalyst layer is Rm (A2), Rm (A1)>Rm (A2) holds.

3 . The catalyst laminate according to claim 1 , wherein the Rm (A1) is 0.1 or more and 1.0 or less.

4 . The catalyst laminate according to claim 1 , wherein the Rm (A2) is 0.01 or more and 0.45 or less.

5 . The catalyst laminate according to claim 1 , wherein an average thickness of the first catalyst layer is larger than that of the second catalyst layer.

6 . The catalyst laminate according to claim 1 , wherein an average thickness of the first catalyst layer is 4 nm or more and 35 nm or less.

7 . The catalyst laminate according to claim 1 , wherein an average thickness of the second catalyst layer is 2 nm or more and 34 nm or less.

8 . The catalyst laminate according to claim 1 , wherein a pillar connecting the first catalyst layers is present in the second catalyst layer.

9 . The catalyst laminate according to claim 1 , wherein a ratio of a catalyst not present in the first catalyst layer is 30% or more and less than 90%.

10 . The catalyst laminate according to claim 1 , wherein the noble metal or its oxide contains at least one selected from a group including Ir, Pt, Ru, Rh, Os, Pd, and Au and the non-noble metal or its oxide contains at least one selected from a group including Fe, Co, Ni, Mn, Al, Zn, Ta, W, Hf, Si, Mo, Ti, Zr, Nb, V, Cr, Sn, and Sr.

11 . The catalyst laminate according to claim 1 , wherein the first catalyst layer is in direct contact with the second catalyst layer.

12 . A membrane electrode assembly comprising the catalyst laminate according to claim 1 .

13 . An electrochemical cell comprising the membrane electrode assembly according to claim 12 .

14 . A stack comprising the electrochemical cell according to claim 13 .

15 . A water electrolyzer using the stack according to claim 14 .

16 . A hydrogen utilizing system comprising the electrochemical cell according to claim 13 .

17 . A hydrogen utilizing system comprising the stack according to claim 14 .

18 . A hydrogen utilizing system comprising the water electrolyzer according to claim 15 .

Assignees

• Toshiba Kk

Inventors

• Iida Atsuko
• Yoshinaga Norihiro
• Mei Wu
• Nakano Yoshihiko

Classifications

• H01M4/8657

  layered · CPC title

• C23C14/083

  of refractory metals or yttrium · CPC title

• C23C14/0036

  Reactive sputtering · CPC title

• H01M8/1004 Primary

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• C25B1/10

  Chemistry & Metallurgy · mapped topic