Recent advances in copper-based catalysts for electrocatalytic CO_(2) reduction toward multi-carbon products

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 C1 products(carbon monoxide,formic acid,etc),C2 products(ethylene,ethanol,etc.)and multi-carbon products(e.g.,n-propanol),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(C2+)products have attracted increasing concerns on the design of catalysts in comparison with those of C1 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.