Device and method for reducing carbon dioxide

Abstract

A device for reducing carbon dioxide includes a vessel for holding an electrolyte solution including carbon dioxide, a working electrode and a counter electrode. The working electrode contains metal hexaboride particles.

1 . A method for reducing carbon dioxide by using a device for reducing carbon dioxide, the method comprising:
 a step (a) of preparing the device, the device comprising:
 a vessel; 
 a working electrode, and 
 a counter electrode, wherein: 
 an electrolytic solution is hold in the vessel, 
 the working electrode contains at least one boride selected from the group consisting of strontium hexaboride (SrB 6 ), calcium hexaboride (CaB 6 ), barium hexaboride (BaB 6 ), lanthanum hexaboride (LaB 6 ), and cerium hexaboride (CeB 6 ), 
 the counter electrode contains metal, 
 the boride is in contact with the electrolytic solution, 
 the metal is in contact with the electrolytic solution, and 
 the electrolytic solution contains the carbon dioxide; and 
   a step (b) of applying a negative voltage and a positive voltage to the working electrode and the counter electrode respectively to reduce the carbon dioxide contained in the electrolytic solution.   
     
     
         2 . The method according to  claim 1 , wherein:
 the device further comprises a solid electrolyte membrane, and   the solid electrolyte membrane is interposed between the working electrode and the counter electrode.   
     
     
         3 . The method according to  claim 1 , wherein in the step (b), a potential difference applied between the working electrode and the counter electrode is not less than 2.0 volts. 
     
     
         4 . The method according to  claim 1 , wherein in the step (b), at least one of methane, ethylene, ethan, and formic acid is generated. 
     
     
         5 . A device for reducing carbon dioxide, the device comprising:
 a vessel for holding an electrolyte solution including carbon dioxide;   a working electrode, and   a counter electrode, wherein:   the working electrode contains at least one boride selected from the group consisting of strontium hexaboride (SrB 6 ), calcium hexaboride (CaB 6 ), barium hexaboride (BaB 6 ), lanthanum hexaboride (LaB 6 ), and cerium hexaboride (CeB 6 ).   
     
     
         6 . The device according to  claim 5 , wherein the counter electrode contains one of platinum, gold, silver, copper, nickel and titanium. 
     
     
         7 . The device according to  claim 5 , wherein the working electrode contains particles of the at least one boride disposed on a substrate. 
     
     
         8 . The device according to  claim 7 , wherein the substrate is a carbon paper, a noble metal substrate, a glassy carbon substrate or a conductive silicon substrate. 
     
     
         9 . The device according to  claim 5 , further comprising a solid electrolyte membrane interposed between the working electrode and the counter electrode. 
     
     
         10 . The device according to  claim 5 , further comprising a reference electrode.