Method of forming composite catalyst layer, structure for electrochemical reaction device, and electrochemical reaction device

Abstract

A method of forming a composite catalyst layer includes repeating a first step of forming a first deposit part and a second step of forming a second deposit part to alternately deposit the first and second catalyst materials. At least one effective thickness out of a first effective thickness calculated from a growth rate of the first deposit part and a second effective thickness calculated from a growth rate of the second deposit part is not less than 0.02 nm nor more than 0.5 nm.

What is claimed is: 
     
         1 . A method of forming a composite catalyst layer comprising
 repeating a first step of forming a first deposit part by depositing a first catalyst material on a substrate and a second step of forming a second deposit part by depositing a second catalyst material in contact with a surface of the first deposit part on the substrate, to alternately deposit the first and second catalyst materials,   wherein at least one effective thickness out of a first effective thickness calculated from a growth rate of the first deposit part and a second effective thickness calculated from a growth rate of the second deposit part is not less than 0.02 nm nor more than 0.5 nm.   
     
     
         2 . The method of  claim 1 , wherein the first and second catalyst materials are deposited using an atomic layer deposition method. 
     
     
         3 . The method of  claim 1 ,
 wherein the first catalyst material contains a first metal, an oxide of the first metal, or a nitride of the first metal, and   wherein the second catalyst material contains a second metal, an oxide of the second metal, or a nitride of the second metal.   
     
     
         4 . The method of  claim 1 , wherein a deposit part having the effective thickness of not less than 0.02 nm nor more than 0.5 nm out of the first deposit part and the second deposit part has a discontinuous structure including a gap part. 
     
     
         5 . The method of  claim 1 , wherein, in a deposit part having the effective thickness of not less than 0.02 nm nor more than 0.5 nm out of the first deposit part and the second deposit part, a number density of metal atoms of the catalyst material is not less than 1.0×10 5  nor more than 1.0×10 7  per unit area of 1 micrometer×1 micrometer, the number density being calculated from a three-dimension atom probe analysis result of the composite catalyst layer. 
     
     
         6 . The method of  claim 1 , wherein the substrate contains at least one of a carbon material, a metal material, a metal oxide, and a semiconductor material. 
     
     
         7 . The method of  claim 1 , wherein the first and second deposit parts is not heated at a temperature higher than a deposition temperature of the first catalyst material and higher than a deposition temperature of the second catalyst material after repeating the first and second steps. 
     
     
         8 . A structure for an electrochemical reaction device comprising:
 a substrate containing at least one of a carbon material, a metal material, a metal oxide, and a semiconductor material; and   a composite catalyst layer disposed on the substrate,   wherein the composite catalyst layer contains a first metal element selected from the group consisting of transition metals and a second metal element having 2.0 electronegativity or more.   
     
     
         9 . The structure of  claim 8 ,
 wherein the first metal element is Co, Ni, Fe, or Mn, and   wherein the second metal element is Mo, W, Ru, Os, Rh, Ir, Pd, Pt, or Au.   
     
     
         10 . An electrochemical reaction device comprising:
 an electrolytic solution tank comprising a first storage part storing a first electrolytic solution and a second storage part storing a second electrolytic solution;   a first catalyst layer immersed in the first electrolytic solution to oxidize the first electrolytic solution; and   a second catalyst layer immersed in the second electrolytic solution to reduce the second electrolytic solution,   wherein the first catalyst layer contains a first metal element selected from the group consisting of transition metals and a second metal element having 2.0 electronegativity or more.   
     
     
         11 . The device of  claim 10 ,
 wherein the first metal element is Co, Ni, Fe, or Mn, and   wherein the second metal element is Mo, W, Ru, Os, Rh, Ir, Pd, Pt, or Au.