Toward Durable CO2 Electroreduction with Cu‐Based Catalysts via Understanding Their Deactivation Modes

Abstract The technology of CO 2 electrochemical reduction (CO 2 ER) provides a means to convert CO 2 , a waste greenhouse gas, into value‐added chemicals. Copper is the most studied element that is capable of catalyzing CO 2 ER to obtain multicarbon products, such as ethylene, ethanol, acetate, etc., at an appreciable rate. Under the operating condition of CO 2 ER, the catalytic performance of Cu decays because of several factors that alters the surface properties of Cu. In this review, these factors that cause the degradation of Cu‐based CO 2 ER catalysts are categorized into generalized deactivation modes, that are applicable to all electrocatalytic systems. The fundamental principles of each deactivation mode and the associated effects of each on Cu‐based catalysts are discussed in detail. Structure‐ and composition‐activity relationship developed from recent in situ/operando characterization studies are presented as evidence of related deactivation modes in operation. With the aim to address these deactivation modes, catalyst design and reaction environment engineering rationales are suggested. Finally, perspectives and remarks built upon the recent advances in CO 2 ER are provided in attempts to improve the durability of CO 2 ER catalysts.