Process and high surface area electrodes for the electrochemical reduction of carbon dioxide
View Patent ↗Methods and systems for electrochemical conversion of carbon dioxide to organic products including formate and formic acid are provided. A method may include, but is not limited to, steps (A) to (C). Step (A) may introduce an acidic anolyte to a first compartment of an electrochemical cell. The first compartment may include an anode. Step (B) may introduce a bicarbonate-based catholyte saturated with carbon dioxide to a second compartment of the electrochemical cell. The second compartment may include a high surface area cathode including indium and having a void volume of between about 30% to 98%. At least a portion of the bicarbonate-based catholyte is recycled. Step (C) may apply an electrical potential between the anode and the cathode sufficient to reduce the carbon dioxide to at least one of a single-carbon based product or a multi-carbon based product.
1. A method for electrochemical reduction of carbon dioxide into products, comprising:
(A) introducing an acidic anolyte to a first compartment of an electrochemical cell, the first compartment including an anode;
(B) introducing an alkali metal bicarbonate-based catholyte saturated with carbon dioxide to a second compartment of the electrochemical cell, the second compartment including a high surface area cathode, the high surface area cathode including a conductive base electrode structure and at least two electrocatalysts on the conductive base electrode structure, a first electrocatalyst of the at least two electrocatalysts including a metal, the first electrocatalyst is a layer covering the conductive base electrode structure, a second electrocatalyst of the at least two electrocatalysts is another layer on the first electrocatalyst, the high surface area cathode having a void volume of between about 30% to 98%, at least a portion of the alkali metal bicarbonate-based catholyte being recycled; and
(C) applying an electrical potential between the anode and the high surface area cathode sufficient to reduce the carbon dioxide to at least one of a single-carbon based product or a multi-carbon based product.
2. The method of claim 1 , wherein applying an electrical potential between the anode and the cathode sufficient to reduce the carbon dioxide to at least one of a single-carbon based product or a multi-carbon based product comprises:
applying the electrical potential between the anode and the high surface area cathode sufficient to reduce the carbon dioxide to the single-carbon based product, the single carbon-based product including an alkali metal formate.
3. The method of claim 1 , wherein the second compartment further includes a homogenous heterocyclic amine catalyst.
4. The method of claim 3 , wherein the homogenous heterocyclic amine catalyst is selected from the group consisting of 4-hydroxy pyridine, adenine, a heterocyclic amine containing sulfur, a heterocyclic amine containing oxygen, an azole, a benzimidazole, a bipyridine, a furan, an imidazole, an imidazole related species with at least one five-member ring, an indole, a lutidine, a methylimidazole, an oxazole, a phenanthroline, a pterin, a pteridine, pyridine, a pyridine related species with at least one six-member ring, a pyrrole, a quinoline, and a thiazole.
5. The method of claim 1 , wherein the anode comprises an electrocatalytic coating including at least one of ruthenium oxide, iridium oxide, a platinum oxide, gold, and a gold oxide.
6. The method of claim 1 , wherein the electrochemical cell includes a membrane configured to selectively control a flow of ions between the first compartment and the second compartment.
7. The method of claim 1 , wherein the high surface area cathode has a surface area of 2 to 2000 cm 2 /cm 3 .
8. The method of claim 1 , wherein the first electrocatalyst is tin foil and the second electrocatalyst is an indium composition.
9. The method of claim 1 , wherein the conductive base electrode structure includes copper.
10. The method of claim 1 , wherein the high surface area cathode has structure which has a specific surface area which varies in a horizontal or vertical direction.
11. The method of claim 1 , wherein the second electrocatalyst of the at least two electrocatalysts is applied as a coating on the first electrocatalyst.
12. A method for electrochemical reduction of carbon dioxide into products, comprising:
(A) introducing an acidic anolyte to a first compartment of an electrochemical cell, the first compartment including an anode;
(B) introducing an alkali metal bicarbonate-based catholyte saturated with carbon dioxide to a second compartment of the electrochemical cell, the second compartment including a high surface area cathode, the high surface area cathode including a conductive base electrode and at least two electrocatalysts on the conductive base electrode, a first electrocatalyst of the at least two electrocatalysts including a metal, the first electrocatalyst is a layer covering the conductive base electrode structure, a second electrocatalyst of the at least two electrocatalysts is another layer on the first electrocatalyst, the second electrocatalyst of the at least two electrocatalysts is applied as a coating on the first electrocatalyst, the high surface area cathode having a void volume of between about 30% to 98%, at least a portion of the alkali metal bicarbonate-based catholyte being recycled; and
(C) applying an electrical potential between the anode and the high surface area cathode sufficient to reduce the carbon dioxide to a multi-carbon based product.
13. The method of claim 12 , wherein the second compartment further includes a homogenous heterocyclic amine catalyst.
14. The method of claim 13 , wherein the homogenous heterocyclic amine catalyst is selected from the group consisting of 4-hydroxy pyridine, adenine, a heterocyclic amine containing sulfur, a heterocyclic amine containing oxygen, an azole, a benzimidazole, a bipyridine, a furan, an imidazole, an imidazole related species with at least one five-member ring, an indole, a lutidine, a methylimidazole, an oxazole, a phenanthroline, a pterin, a pteridine, pyridine, a pyridine related species with at least one six-member ring, a pyrrole, a quinoline, and a thiazole.
15. The method of claim 12 , wherein the anode comprises an electrocatalytic coating including at least one of ruthenium oxide, iridium oxide, a platinum oxide, gold, and a gold oxide.
16. The method of claim 12 , wherein the electrochemical cell includes a membrane configured to selectively control a flow of ions between the first compartment and the second compartment.
17. The method of claim 12 , wherein the high surface area cathode has a surface area of 2 to 2000 cm 2 /cm 3 .
18. The method of claim 12 , wherein the first electrocatalyst is tin foil.
19. The method of claim 18 , wherein the second electrocatalyst is an indium composition.
20. The method of claim 19 , wherein the indium composition covers a range of 5% to 100% of the tin foil.
21. The method of claim 12 , wherein the conductive base electrode structure includes copper.
22. The method of claim 12 , wherein the high surface area cathode has structure which has a specific surface area which varies in a horizontal or vertical direction.