Product selectivity for CO2 reduction

1. A CO2 reduction system, comprising:

a cathode in contact with a catholyte,

the cathode including a selectivity-determining layer electrodeposited on an electron conductor, the selectivity-determining layer including a selectivity-determining component that includes a backbone of substituted heterocyle, and

the catholyte includes CO2, an additive and a reduced from of the additive forming the selectivity-determining component,

wherein the CO2 is reduced at the cathode and wherein the selectivity determining component is simultaneously electrodeposited.

2. The system of claim 1 , wherein the substituted heterocycle includes one or more nitrogens in a ring structure.

3. The system of claim 1 , wherein a substituent on the substituted heterocycle includes an aryl group.

4. The system of claim 3 , wherein the aryl group is substituted.

5. The system of claim 1 , wherein the additive is positively charged.

6. The system of claim 1 , wherein the selectivity-determining component is selected from a group consisting of a dimer, an oligomer, and a polymer.

7. The system of claim 1 , wherein the substituted heterocycle is one of multiple substituted heterocycles included in the selectivity-determining component and the selectivity-determining component includes multiple units that each includes one or more of the substituted heterocycles.

8. The system of claim 7 , wherein the selectivity-determining component is represented by:

where different portions of R 1-9 are the same or different and individually represent an H, an alkyl group, an aryl group, a hydrocarbyl group, a halogen, an alkoxy group, a thiol, an aminyl group, a phosphorous-containing group, a silicon-containing group, and a boron-containing group.

9. The system of claim 6 , wherein the selectivity-determining component is represented by:

where L represents nil or an organic linker, n is greater than or equal to 1, R 21-27 individually represent an H, alkyl group, aryl group, hydrocarbyl group, halogen, alkoxy group, thiol, aminyl group, phosphorous-containing group, silicon-containing group, and a boron-containing group.

10. The system of claim 1 , wherein the catholyte includes the additive that can be reduced from which the selectivity-determining component can be formed by electrodeposition.

11. The system of claim 10 , wherein the additive is positively charged.

12. The system of claim 11 , wherein the additive is represented by

wherein R 1 represents an H, alkyl group, aryl group, hydrocarbyl group, halogen, alkoxy group, thiol, aminyl group, phosphorous-containing group, silicon-containing group, and a boron-containing group and R 2 represents an H, alkyl group, aryl group, hydrocarbyl group, halogen, alkoxy group, thiol, aminyl group, phosphorous-containing group, silicon-containing group, and a boron-containing group and.

13. A CO 2 reduction system, comprising:

a cathode in contact with a catholyte,

the catholyte including CO 2 and an additive, the additive including a positively charged substituted heterocycle; and

the cathode comprising a polymeric layer comprising a backbone of substituted heterocycles obtained from a reduced form of the additive.

14. The system of claim 13 , wherein the substituted heterocycle includes one or more nitrogens in a ring structure.

15. The system of claim 14 , wherein the substituted heterocycle includes a substituent linked to one of the nitrogens in the ring structure.

16. The system of claim 15 , wherein the substituent includes an aryl.

17. A method of reducing CO 2 , comprising:

reducing an additive included in a catholyte in contact with a cathode that includes an electron conductor, the additive being reduced so as to generate a reduced additive,

processing the reduced additive so as to generate a selectivity component, processing the reduced additive includes dimerizing the reduced additive so as to generate the selectivity component, oligomerizing the reduced additive so as to generate the selectivity component, and/or polymerizing the reduced additive so as to generate the selectivity component, and

forming a selectivity-determining layer on the electron conductor, the selectivity-determining layer including the selectivity component while simultaneously reducing CO 2 at the cathode.

18. The method of claim 17 , wherein the electron conductor is polycrystalline copper.

19. The method of claim 17 , further comprising:

reducing the CO 2 at the cathode so as to generate multiple different CO 2 reduction products that is more than 70% C ≥2 .