Amino Assisted Protonation for Carbon-Carbon Coupling during Electroreduction of Carbon Dioxide to Ethylene on Copper(I) Oxide

The development of effective catalysts for the electrocatalytic carbon dioxide reduction reaction (CO2RR) to two-carbon (C-2) products is a practical approach to solve the energy crisis and stabilize the carbon cycle of the ecosystem. The production of electrocatalytic CO2RR with copper metal shows low selectivity and mainly generates one-carbon (C-1) products, hindering its wide practical application. The use of copper (I) oxide (Cu2O) in electrocatalysis has attracted intense research attention because it can more efficiently produce C-2 products with high energy density such as ethylene (C2H4) and ethane (C2H6). We use an amino-modified Cu2O catalyst (NH2-Cu2O) for electrocatalytic CO2RR to obtain significantly increased production of the CO and C-2 products. Electrochemical in-situ infrared spectroscopy analysis was used to detect the presence of the *COOH and *CHO reaction intermediates. Density functional theory calculations showed that the amino (-NH2) modification reduces the free energy of the *CO ->*CHO reaction that is the rate-determining step in C2H4 production. Our results show that amino modification can promote the protonation of *CO and *CHO carbon-carbon coupling to produce C2H4. Thus, amino-modified copper-based catalysts are promising materials for application in electrocatalytic CO2RR to multi-carbon products.

Automated summary

This study demonstrated the enhanced production of CO and C-2 products using an amino-modified Cu2O catalyst in electrocatalytic CO2RR. Experimental and computational analysis confirmed the promoting effect of amino modification on C2H4 production, offering a new perspective for the application of such catalysts in the field of CO2RR.