Gas diffusion electrode and electrochemical reaction device

Abstract

Provided are a gas diffusion electrode that enables efficient production of C2 compounds at high current density; and an electrochemical reaction device including such a gas diffusion electrode. The gas diffusion electrode is for electrochemically reducing one or both of carbon dioxide and carbon monoxide. The gas diffusion electrode includes a gas diffusion layer; and a catalyst layer provided on a surface of the gas diffusion layer. The catalyst layer includes catalyst particles including a copper (Cu) component; and hydrophobic particles including a fluororesin. In the catalyst layer, the catalyst particles have a mass per unit area (M1) of 0.70 mg/cm2 or more, and the hydrophobic particles have a mass per unit area (M2) with a ratio (M2/M1) of M2 to M1 being 0.10 or more and 1.70 or less.

What is claimed is: 
     
         1 . A gas diffusion electrode for electrochemically reducing one or both of carbon dioxide and carbon monoxide,
 the gas diffusion electrode comprising: a gas diffusion layer; and a catalyst layer provided on a surface of the gas diffusion layer,   the catalyst layer comprising: catalyst particles; and   hydrophobic particles,   the catalyst particles comprising a copper (Cu) component, the hydrophobic particles comprising a fluororesin,   the catalyst particles having a mass per unit area (M 1 ) of 0.70 mg/cm 2  or more in the catalyst layer,   the hydrophobic particles having a mass per unit area (M 2 ) with a ratio (M 2 /M 1 ) of M 2  to M 1  being 0.10 or more and 1.70 or less in the catalyst layer.   
     
     
         2 . The gas diffusion electrode according to  claim 1 , wherein the mass per unit area (M 2 ) of the hydrophobic particles in the catalyst layer is 0.10 mg/cm 2  or more. 
     
     
         3 . The gas diffusion electrode according to  claim 1 , wherein the catalyst layer comprises a mixture of the catalyst particles and the hydrophobic particles. 
     
     
         4 . The gas diffusion electrode according to  claim 1 , wherein the catalyst layer has a thickness of 200 μm or less. 
     
     
         5 . The gas diffusion electrode according to  claim 1 , wherein the copper (Cu) component is metallic copper. 
     
     
         6 . The gas diffusion electrode according to  claim 1 , wherein the fluororesin comprises polytetrafluoroethylene. 
     
     
         7 . The gas diffusion electrode according to  claim 1 , wherein the gas diffusion electrode is a cathode electrode. 
     
     
         8 . An electrochemical reaction device for electrochemically reducing one or both of carbon dioxide and carbon monoxide, the electrochemical reaction device comprising: a cathode; an anode; an anion exchange membrane provided between the cathode and the anode; a cathode-side liquid flow channel provided between the cathode and the anion exchange membrane; and an anode-side liquid flow channel provided between the anode and the anion exchange membrane,
 the cathode comprising the gas diffusion electrode according to  claim 1 .