Carbon Dioxide Gas-Phase Reduction Device and Carbon Dioxide Gas-Phase Reduction Method

Abstract

The efficiency of a carbon dioxide reduction reaction at a reduction electrode is improved. An oxidation tank including an oxidation electrode, a reduction tank which is adjacent to the oxidation tank and to which carbon dioxide is supplied, and a gas reduction sheet located between the oxidation tank and the reduction tank are included, the gas reduction sheet is a sheet in which an ion exchange membrane and a reduction electrode are laminated, the ion exchange membrane is located on the oxidation tank side, the reduction electrode is located on the reduction tank side, is connected to the oxidation electrode by a lead, and conduct conducts a reduction reaction of the carbon dioxide by a current flowing through the lead.

1 . A carbon dioxide gas phase reduction apparatus comprising:
 an oxidation tank including an oxidation electrode;   a reduction tank which is adjacent to the oxidation tank and to which carbon dioxide is supplied; and   a gas reduction sheet located between the oxidation tank and the reduction tank, wherein   the gas reduction sheet is a sheet in which an ion exchange membrane and a reduction electrode are laminated,   the ion exchange membrane is located on a side of the oxidation tank, and   the reduction electrode is located on a side of the reduction tank, is connected to the oxidation electrode by a lead, and conducts a reduction reaction of the carbon dioxide by a current flowing through the lead.   
     
     
         2 . The carbon dioxide gas phase reduction apparatus according to  claim 1 , further comprising a light source for irradiating the oxidation electrode with light. 
     
     
         3 . The carbon dioxide gas phase reduction apparatus according to  claim 1 , further comprising a power source connected to the lead. 
     
     
         4 . The carbon dioxide gas phase reduction apparatus according to  claim 1 , wherein the oxidation electrode comprises an n-type semiconductor. 
     
     
         5 . A carbon dioxide gas phase reduction method performed in a carbon dioxide gas phase reduction apparatus, the carbon dioxide gas phase reduction apparatus including an oxidation tank including an oxidation electrode, a reduction tank adjacent to the oxidation tank, and a gas reduction sheet located between the oxidation tank and the reduction tank, the gas reduction sheet being a sheet in which an ion exchange membrane and a reduction electrode are laminated, the ion exchange membrane being located on a side of the oxidation tank, the reduction electrode being located on a side of the reduction tank and connected to the oxidation electrode by a lead, the gas phase reduction method comprising:
 filling the oxidation tank with an aqueous solution;   supplying carbon dioxide to the reduction tank, and   flowing an electric current through the lead to cause a reduction reaction of the carbon dioxide at the reduction electrode.   
     
     
         6 . The gas phase reduction method for carbon dioxide according to  claim 5 , wherein the aqueous solution is any one of a potassium hydroxide aqueous solution, a rubidium hydroxide aqueous solution, and a cesium hydroxide aqueous solution.