Recent advances in copper-based catalysts for electrocatalytic CO ₂ reduction toward multi-carbon products

Abstract

Electrocatalytic carbon dioxide reduction reaction (CO 2 RR) holds the promise of both overcoming the greenhouse effect and synthesizing a wealth of chemicals. Electrocatalytic CO 2 reduction toward carbon-containing products, including C 1 products (carbon monoxide, formic acid, etc), C 2 products (ethylene, ethanol, etc.) and multi-carbon products (e.g., npropanol), provides beneficial fuel and chemicals for industrial production. The complexity of the multi-proton transfer processes and difficulties of C-C coupling in electrochemical CO 2 reduction toward multi-carbon(C 2+ ) products have attracted increasing concerns on the design of catalysts in comparison with those of C 1 products. In this paper, we review the main advances in the syntheses of multi-carbon products through electrocatalytic carbon dioxide reduction in recent years, introduce the basic principles of electrocatalytic CO 2 RR, and detailly elucidate two widely accepted mechanisms of C-C coupling reactions. Among abundant nanomaterials, copper-based catalysts are outstanding catalysts for the preparation of multi-carbon chemicals in electrochemical CO 2 RR attributing to effective C-C coupling reactions. Regarding the different selectivity of multi-carbon chemicals but extensively applied copper-based catalysts, we classify and summarize various Cu-based catalysts through separating diverse multi-carbon products, where the modification of spatial and electronic structures is beneficial to increase the coverage of CO or lower the activation energy barrier for forming C-C bond to form the key intermediates and increase the production of multi-carbon products. Challenges and prospects involving the fundamental and development of copper-based catalysts in electrochemical CO 2 reduction reaction are also proposed.