Electrochemical reaction device

Abstract

An electrochemical reaction device comprises: an anode to oxidize water; an electrolytic solution flow path facing on the anode and through which an electrolytic solution containing the water flows; a cathode including: a porous conductive layer having first and second surfaces; and a reduction catalyst layer having a third surface disposed on the first surface and containing a reduction catalyst to reduce carbon dioxide; a separator between the anode and the cathode; a power supply connected to the anode and the cathode; and a flow path plate including: a fourth surface on the second surface; and a flow path facing on the second surface and through which the carbon dioxide flows. A ratio of an area of an overlap of the second surface and the flow path to an area of the second surface is 0.5 or more and 0.85 or less.

What is claimed is: 
     
         1 . An electrochemical reaction device, comprising:
 an anode to oxidize water and thus generate oxygen;   an electrolytic solution flow path facing on the anode and through which an electrolytic solution containing the water flows;   a cathode including: a porous conductive layer having a first surface and a second surface; and a reduction catalyst layer having a third surface disposed on the first surface and containing a reduction catalyst to reduce carbon dioxide and thus generate a carbon compound;   a separator between the anode and the cathode;   a power supply connected to the anode and the cathode; and   a flow path plate including: a fourth surface on the second surface; and a flow path facing on the second surface and through which the carbon dioxide flows,   wherein a ratio of an area of an overlap of the second surface and the flow path to an area of the second surface is 0.5 or more and 0.85 or less.   
     
     
         2 . The device according to  claim 1 ,
 wherein a ratio of an area of an overlap of the third surface and the flow path to an area of the third surface is 0.5 or more and 0.85 or less.   
     
     
         3 . The device according to  claim 1 ,
 wherein the flow path has a first region, a second region, and a third region, the first region extending on the fourth surface, the third region extending along the first region, and the second region extending and bending from the first region to the third region,   a ratio of an average width of the first region to an average width between the first and third regions is 1.5 or more and 5 or less.   
     
     
         4 . The device according to  claim 1 ,
 wherein if the second surface is divided into a polygonal portion and a remainder portion, the polygonal portion is formed by connecting vertexes of the overlap of the second surface and the flow path, each of interior angles of the overlap thereof corresponding to the vertexes is less than 180 degrees, and a ratio of an area of the remainder portion to the area of the second surface is ⅙ or less.   
     
     
         5 . The device according to  claim 1 ,
 wherein if the second surface is divided into a polygonal portion and a remainder portion, the polygonal portion is formed by connecting vertexes of the overlap of the third surface and the flow path, each of interior angles of the overlap thereof corresponding to the vertexes is less than 180 degrees, and a ratio of an area of the remainder portion to the area of the third surface is ⅙ or less.   
     
     
         6 . The device according to  claim 1 ,
 wherein if an overlap of the second and fourth surfaces is divided along first lines and second lines except for the overlap of the second surface and the flow path, the first lines are away from each other along a first direction of the fourth surface at intervals of 0.1 mm, the second lines are away from each other along a second direction perpendicular to the first direction along the fourth surface at intervals of 0.1 mm, the first lines and the second lines cross each other to define intersection points, and a standard deviation of shortest distances between each of the intersection points and the overlap of the second surface and the flow path is 0.8 or less.   
     
     
         7 . The device according to  claim 1 ,
 wherein if an overlap of the third and fourth surfaces is divided along first lines and second lines except for the overlap of the third surface and the flow path, the first lines are away from each other along a first direction of the fourth surface at intervals of 0.1 mm, the second lines are away from each other along a second direction perpendicular to the first direction along the fourth surface at intervals of 0.1 mm, the first lines and the second lines cross each other to define intersection points, and a standard deviation of shortest distances between each of the intersection points and the overlap of the third surface and the flow path is 0.8 or less.   
     
     
         8 . The device according to  claim 1 ,
 wherein if an overlap of the second and fourth surfaces is divided along first lines and second lines except for the overlap of the second surface and the flow path, the first lines are away from each other along a first direction of the fourth surface at intervals of 0.1 mm, the second lines are away from each other along a second direction perpendicular to the first direction along the fourth surface at intervals of 0.1 mm, the first lines and the second lines cross each other to define intersection points, and shortest distances between each of 30% or less of the intersection points in a number ratio and the overlap of the second surface and the flow path is 0.5 mm or more.   
     
     
         9 . The device according to  claim 1 ,
 wherein if an overlap of the third and fourth surfaces is divided along first lines and second lines except for the overlap of the third surface and the flow path, the first lines are away from each other along a first direction of the third surface at intervals of 0.1 mm, the second lines are away from each other along a second direction perpendicular to the first direction along the third surface at intervals of 0.1 mm, the first lines and the second lines cross each other to define intersection points, and shortest distances between each of 30% or less of the intersection points in a number ratio and the overlap of the third surface and the flow path is 0.5 mm or more.