Electrochemical production of urea from NOx and carbon dioxide
View Patent ↗Methods and systems for electrochemical production of urea are disclosed. A method may include, but is not limited to, steps (A) to (B). Step (A) may introduce carbon dioxide and NOx to a solution of an electrolyte and a heterocyclic catalyst in an 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 may reduce the carbon dioxide and the NOx into a first sub-product and a second sub-product, respectively. Step (B) may combine the first sub-product and the second sub-product to produce urea.
1. A method for electrochemical production of urea, comprising:
(A) introducing carbon dioxide and a nitrogen oxide to a solution of an electrolyte and a heterocyclic catalyst in an electrochemical cell, wherein (i) said electrochemical cell including an anode in a first cell compartment and a cathode in a second cell compartment, (ii) said cathode reducing said carbon dioxide into a first sub-product and reducing said nitrogen oxide into a second sub-product, and (iii) said heterocyclic catalyst includes at least one of adenine, a heterocyclic amine containing sulfur, a heterocyclic amine containing oxygen, an azole, benzimidazole, a bipyridine, furan, an imidazole, an imidazole related species with at least one five-member ring, an indole, methylimidazole, an oxazole, phenanthroline, pterin, pteridine, a pyridine, a pyridine related species with at least one six-member ring, pyrrole, quinoline, or a thiazole; and
(B) combining said first sub-product and said second sub-product to produce urea.
2. The method of claim 1 , wherein said nitrogen oxide includes at least one of nitrite or nitrate.
3. The method of claim 1 , wherein said first sub-product is at least one of carbon monoxide or a reduced CO 2 intermediate species, and wherein said second sub-product is at least one of ammonia or an ammonia-related intermediate compound.
4. The method of claim 1 , wherein said cathode includes 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, or degenerately doped p-Si:B.
5. The method of claim 1 , wherein said cathode includes a first cathode material for reducing said carbon dioxide and a second material for reducing said nitrogen oxide.
6. The method of claim 5 , wherein said first cathode material includes at least one of tin, silver, copper, steel, or an alloy including at least one of copper or nickel.
7. The method of claim 5 , wherein said second cathode material includes at least one of nickel, platinum, or gold.
8. A method for electrochemical production of urea, comprising:
(A) introducing carbon dioxide and a nitrogen oxide to a solution of an electrolyte and a heterocyclic catalyst in an electrochemical cell, wherein (i) said electrochemical cell including an anode in a first cell compartment and a cathode in a second cell compartment, (ii) said cathode reducing said carbon dioxide into a first sub-product and reducing said nitrogen oxide into a second sub-product, (iii) said heterocyclic catalyst includes at least one of adenine, a heterocyclic amine containing sulfur, a heterocyclic amine containing oxygen, an azole, benzimidazole, a bipyridine, furan, an imidazole, an imidazole related species with at least one five-member ring, an indole, methylimidazole, an oxazole, phenanthroline, pterin, pteridine, a pyridine, a pyridine related species with at least one six-member ring, pyrrole, quinoline, or a thiazole; and
(B) combining said first sub-product and said second sub-product to produce urea; and
(C) varying a yield of urea by adjusting at least one of (a) a material of said cathode, (b) said heterocyclic catalyst, (c) an electrical potential of said cathode, and (d) said electrolyte.
9. The method of claim 8 , wherein said material of said cathode includes 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, or degenerately doped p-Si:B.
10. The method of claim 8 , wherein said electrical potential of said cathode ranges between approximately −0.5 volts to approximately −1.5 volts.
11. The method of claim 8 , wherein said electrolyte includes 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, or a tetraalkyl ammonium salt.
12. The method of claim 8 , wherein combining said first sub-product and said second sub-product includes combining said first sub-product and said second sub-product in said electrochemical cell to produce urea.
13. The method of claim 8 , wherein said cathode includes a first cathode material for reducing said carbon dioxide and a second material for reducing said nitrogen oxide.
14. The method of claim 13 , wherein said first cathode material includes at least one of tin, silver, copper, steel, or an alloy including at least one of copper or nickel.
15. The method of claim 13 , wherein said second cathode material includes at least one of nickel, platinum, or gold.