Surface Behavior Regulation of Intermediates on the Copper‐Based Catalysts for Enhancing Electrocatalytic CO ₂ Reduction to Ethylene

Abstract Electrocatalytic CO ₂ reduction (CO ₂ RR) on copper‐based catalysts uniquely enables C─C coupling to produce multi‐carbon products such as ethylene and ethanol, owing to their moderate binding affinity toward key intermediates ( ^* CO, ^* H). However, industrial application is hindered by structural instability, imprecise active‐site control, complex product distributions, and competing side reactions. Such structural strategies include facet engineering, defect creation, oxidation‐state modulation, and interface engineering, which have improved selectivity, yet most focus on static structure–performance relationships, overlooking dynamic surface behaviors of intermediates. This review builds a mechanism‐centered framework along the CO ₂ RR pathway (CO ₂ activation, ^* CO enrichment, ^* CO dimerization) to elucidate how adsorption configuration, spatial distribution, coverage dynamics, and transformation kinetics of intermediates govern selectivity, providing both theoretical guidance and practical strategies for the development of next‐generation Cu‐based CO ₂ RR systems with enhanced selectivity, durability, and industrial applicability.