Identification of CO₂ as a Reactive Reagent for C–C Bond Formation via Copper-Catalyzed Electrochemical Reduction

Abstract

The electrochemical reduction of CO 2 (CO 2 ER) holds great promise as a method to achieve carbon neutrality and revolutionize the utilization of fossil fuels. Advanced catalysts used in CO 2 ER have demonstrated the ability to generate valuable multicarbon products through the formation of carbon−carbon (C−C) bonds. Previous research has predominantly focused on C−C formation by dimerizing *CO or coupling *CO with other *C 1 intermediates. However, the potential coupling of CO 2 with *C 1 intermediates has not been explored experimentally or theoretically despite CO 2 being the exclusive reactant in CO 2 ER and having a high concentration. This study employed DFT calculations and a constant electrode potential model to investigate the possibility of CO 2 + *C 1 couplings on Cu(100) surfaces. Surprisingly, the results indicate that CO 2 can serve as a favorable reagent for C−C bond formation, surpassing the reactivity of *CO under alkaline conditions. The enhanced reactivity of CO 2 compared to that of *CO was elucidated based on a barrier decomposition analysis. Experimental validation was conducted to confirm these theoretical results.

Linking CO to Urea Production from CO2 and NO3–/NO2– Co-Electrolysis on Transition Metals

“…This perspective holds true at highly negative electrode potentials. Under such conditions, CO 2 hydrogenation to CO and NO 3 – /NO 2 – hydrogenation to NH 3 becomes notably accelerated due to their electrochemical nature (involving electron transfer). , In contrast, C–N formation remains less influenced because it predominantly involves a chemical reaction and not electron transfer. , Catalysts that are efficient in coreducing CO 2 and NO x to urea exhibit a high activity for converting CO 2 to CO and NO 3 – /NO 2 – to NH 3 . , Within the CO 2 ER to CO process, there are three potential carbon sources (i.e., CO 2 , *COOH, and *CO) that might couple with *N 1 to forge the C–N bonds. This investigation predominantly focuses on the CO 2 + *N 1 coupling due to the following rationale.…”

“…For an in-depth look into how we handle electronic energy adjustments and construct free energy surfaces, we direct readers to the Supporting Information. This technique has been effectively applied by us − and other scholars − in a wide range of electrochemical studies.…”

“…55,56 In contrast, C−N formation remains less influenced because it predominantly involves a chemical reaction and not electron transfer. 30,47 Catalysts that are efficient in coreducing CO 2 and NO x to urea exhibit a high activity for converting CO 2 to CO and NO 3 − /NO 2 − to NH 3 . 16,17 Within the CO 2 ER to CO process, there are three potential carbon sources (i.e., CO 2 , *COOH, and *CO) 57 that might couple with *N 1 to forge the C−N bonds.…”