Reducing carbon dioxide to products

Abstract

A method for reducing carbon dioxide to one or more products is disclosed. The method may include steps (A) to (C). Step (A) may bubble the carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode generally reduces the carbon dioxide into the products. Step (B) may vary at least one of (i) which of the products is produced and (ii) a faradaic yield of the products by adjusting one or more of (a) a cathode material and (b) a surface morphology of the cathode. Step (C) may separate the products from the solution.

1 . A method for reducing carbon dioxide to one or more products, comprising the steps of:
 (A) bubbling said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell, wherein (i) said divided electrochemical cell comprises an anode in a first cell compartment and a cathode in a second cell compartment and (ii) said cathode reducing said carbon dioxide into said products;   (B) varying at least one of (i) which of said products is produced and (ii) a faradaic yield of said products by adjusting one or more of (a) a cathode material and (b) a surface morphology of said cathode; and   (C) separating said products from said solution.   
     
     
         2 . The method according to  claim 1 , wherein said cathode material is at least one of Al, Au, Ag, C, Cd, Co, Cr, Cu, Cu alloys, Ga, Hg, In, Mo, Nb, Ni, Ni alloys, Ni—Fe alloys, Sn, Sn alloys, Ti, V, W, Zn, elgiloy, Nichrome, austenitic steel, duplex steel, ferritic steel, martensitic steel, stainless steel, degenerately doped p-Si, degenerately doped p-Si:As and degenerately doped p-Si:B. 
     
     
         3 . The method according to  claim 1 , wherein said surface morphology of said cathode comprises a smooth surface. 
     
     
         4 . The method according to  claim 1 , wherein said surface morphology of said cathode comprises a rough surface. 
     
     
         5 . The method according to  claim 1 , wherein said catalyst is one or more of adenine, amines containing sulfur, amines containing oxygen, azoles, benzimidazole, bipyridines, furan, imidazoles, imidazole related species with at least one five-member ring, indoles, methylimidazole, oxazoles, phenanthroline, pterin, pteridine, pyridines, pyridine related species with at least one six-member ring, pyrrole, quinoline and thiazoles. 
     
     
         6 . The method according to  claim 1 , wherein said products comprise one or more of acetaldehyde, acetone, carbon, carbon monoxide, carbonates, ethanol, ethylene, formaldehyde, formic acid, glyoxal, glyoxylic acid, graphite, isopropanol, methane, methanol, oxalate, oxalic acid and polymers containing carbon dioxide. 
     
     
         7 . A method for reducing carbon dioxide to one or more products, comprising the steps of:
 (A) bubbling said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell, wherein (i) said divided electrochemical cell comprises an anode in a first cell compartment and a cathode in a second cell compartment and (ii) said cathode reducing said carbon dioxide into said products;   (B) varying at least one of (i) which of said products is produced and (ii) a faradaic yield of said products by adjusting one or more of (a) said electrolyte and (b) a manner in which said carbon dioxide is bubbled; and   (C) separating said products from said solution.   
     
     
         8 . The method according to  claim 7 , wherein said electrolyte is at least one of Na 2 SO 4 , KCl, NaNO 3 , NaCl, NaF, NaClO 4 , KClO 4 , K 2 SiO 3 , CaCl 2 , a H cation, a Li cation, a Na cation, a K cation, a Rb cation, a Cs cation, a Ca cation, an ammonium cation, an alkylammonium cation, a F anion, a Cl anion, a Br anion, an I anion, an At anion, an alkyl amine, borates, carbonates, nitrites, nitrates, phosphates, polyphosphates, perchlorates, silicates, sulfates, and a tetraalkyl ammonium salt. 
     
     
         9 . The method according to  claim 7 , wherein said bubbling comprises the sub-step of:
 bubbling said carbon dioxide to hit said cathode.   
     
     
         10 . The method according to  claim 7 , wherein said bubbling comprises the sub-step of:
 bubbling said carbon dioxide to miss said cathode.   
     
     
         11 . The method according to  claim 7 , wherein said faradaic yield is at least 20 percent. 
     
     
         12 . The method according to  claim 7 , wherein said cathode comprises a copper-based alloy that remains stable during at least an hour of said reducing. 
     
     
         13 . The method according to  claim 7 , wherein said adjusting includes one or more of (i) a cathode material and (ii) a surface morphology of said cathode. 
     
     
         14 . A method for reducing carbon dioxide to one or more products, comprising the steps of:
 (A) bubbling said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell, wherein (i) said divided electrochemical cell comprises an anode in a first cell compartment and a cathode in a second cell compartment and (ii) said cathode reducing said carbon dioxide into said products;   (B) varying at least one of (i) which of said products is produced and (ii) a faradaic yield of said products by adjusting one or more of (a) a ph level of said solution and (b) an electrical potential; and   (C) separating said products from said solution.   
     
     
         15 . The method according to  claim 14 , wherein said pH level ranges from approximately 3 to approximately 8. 
     
     
         16 . The method according to  claim 14 , wherein said electrical potential ranges from approximately −0.7 volts to −2 volts. 
     
     
         17 . The method according to  claim 14 , further comprising the step of:
 adding to said solution one or more of (i) a hydrogen inhibitor, (ii) a heterocyclic compound and (iii) an alcohol.   
     
     
         18 . The method according to  claim 14 , further comprising the step of:
 performing said reducing at ambient temperature and ambient pressure.   
     
     
         19 . The method according to  claim 14 , wherein said cathode comprises steel. 
     
     
         20 . The method according to  claim 14 , wherein said adjusting includes one or more of (i) a cathode material and (ii) a surface morphology of said cathode.