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

Abstract The technology of CO₂ electrochemical reduction (CO₂ER) provides a means to convert CO₂, a waste greenhouse gas, into value‐added chemicals. Copper is the most studied element that is capable of catalyzing CO₂ER to obtain multicarbon products, such as ethylene, ethanol, acetate, etc., at an appreciable rate. Under the operating condition of CO₂ER, 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 CO₂ER 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 CO₂ER are provided in attempts to improve the durability of CO₂ER catalysts.