Catalytic composition for the electrochemical reduction of carbon dioxide

Abstract

The catalytic composition for the electrochemical reduction of carbon dioxide is a metal oxide supported by multi-walled carbon nanotubes. The metal oxide may be nickel oxide (NiO) or tin dioxide (SnO 2 ). The metal oxides form 20 wt % of the catalyst. In order to make the catalysts, a metal oxide precursor is first dissolved in deionized water to form a metal oxide precursor solution. The metal oxide precursor solution is then sonicated and the solution is impregnated in a support material composed of multi-walled carbon nanotubes to form a slurry. The slurry is then sonicated to form a homogeneous solid solution. Solids are removed from the homogeneous solid solution and dried in an oven for about 24 hours at a temperature of about 110° C. Drying is then followed by calcination in a tubular furnace under an argon atmosphere for about three hours at a temperature of 450° C.

We claim: 
     
         1 . A catalytic composition for the electrochemical reduction of carbon dioxide, comprising a metal oxide supported on multi-walled carbon nanotubes, wherein the metal oxide comprises about 20 wt % of the catalytic composition. 
     
     
         2 . The catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 1 , wherein the metal oxide comprises nickel oxide (NiO). 
     
     
         3 . An electrode for electrochemical reduction of carbon dioxide having the composition of  claim 2  coated thereon. 
     
     
         4 . The catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 1 , wherein the metal oxide comprises tin dioxide (SnO 2 ). 
     
     
         5 . An electrode for electrochemical reduction of carbon dioxide having the composition of  claim 4  coated thereon. 
     
     
         6 . A method of making a catalytic composition for the electrochemical reduction of carbon dioxide, comprising the steps of:
 dissolving nickel nitrate hexahydrate, Ni(NO 3 ) 2 ·6H 2 O, in deionized water to form a nickel precursor solution;   sonicating the nickel precursor solution;   impregnating the sonicated nickel precursor solution in a support material comprising multi-walled carbon nanotubes to form a slurry;   sonicating the slurry to form a homogeneous solid solution;   removing solids from the homogenous solid solution;   drying the solids; and   calcining the dried solids to form the catalytic composition.   
     
     
         7 . The method of making a catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 6 , wherein the step of sonicating the slurry comprises sonicating the slurry for about two hours. 
     
     
         8 . The method of making a catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 6 , wherein the step of drying the solids comprises drying the solids at a temperature of about 110° C. for a period of about 24 hours. 
     
     
         9 . The method of making a catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 6 , wherein the step of calcining the dried solids is performed in an argon atmosphere. 
     
     
         10 . The method of making a catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 9 , wherein the step of calcining the dried solids comprises calcining the dried solids for about three hours at a temperature of about 450° C. 
     
     
         11 . A method of making a catalytic composition for the electrochemical reduction of carbon dioxide, comprising the steps of:
 dissolving tin chloride (SnCl 2 ) in deionized water to form a tin precursor solution;   sonicating the tin precursor solution;   impregnating the sonicated tin precursor solution in a support material comprising multi-walled carbon nanotubes to form a slurry;   sonicating the slurry to form a homogeneous solid solution;   removing solids from the homogenous solid solution;   drying the solids; and   calcining the dried solids to form the catalytic composition.   
     
     
         12 . The method of making a catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 11 , further comprising the step of adding hydrochloric acid (HCl) to the sonicated tin precursor solution. 
     
     
         13 . The method of making a catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 11 , wherein the step of sonicating the slurry comprises sonicating the slurry for about two hours. 
     
     
         14 . The method of making a catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 11 , wherein the step of drying the solids comprises drying the solids at a temperature of about 110° C. for a period of about 24 hours. 
     
     
         15 . The method of making a catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 11 , wherein the step of calcining the dried solids is performed in an argon atmosphere. 
     
     
         16 . The method of making a catalytic composition for the electrochemical reduction of carbon dioxide as recited in  claim 15 , wherein the step of calcining the dried solids comprises calcining the dried solids for about three hours at a temperature of about 450° C.