Progress in the application of Cu-based catalysts in the electroreduction of CO₂ to produce C_xs products

Abstract

Since the industrial revolution, human dependence on fossil fuels has resulted in increasingly severe atmospheric carbon dioxide (CO2) emissions. Electrocatalytic CO2 RR has attracted much attention because of its many advantages, such as mild reaction conditions, controllable reaction rate, low cost and scalable electrolyzer.[7] More importantly, electrocatalytic CO2 RR can control the selective generation of target products by rationally adjusting the reaction potential, electrolyte and catalyst species. However, the CO2 molecular structure is stable, and obtaining the key CO2 -based anionic intermediate CO2– from activated CO2 molecules requires overcoming a huge energy barrier. Copper (Cu) catalysts are the only monometallic catalysts to date that can form two-carbon (C2) products, which establishes their special position in the field. However, the poor selectivity of Cu for a particular product has led to a wide distribution of reduction products, covering the range from carbon monoxide (CO), a reduction product at 2e-, to ethanol (C H25 OH), a reduction product at 12e-. Meanwhile, Cu catalysts are generally less stable, which can seriously affect their commercialization. Currently, in order to obtain highly selective C2+ products (mainly ethylene and ethanol), [16]this article reviews the various methods developed by different scholars in China and abroad to modify Cu catalysts. Finally, this article suggests ways to improve the performance of Cu-based catalysts to enhance the Faraday efficiency of the C2 product from the electroreduction of C02 and gives an outlook on the future direction of Cu-based catalysts.[19]