Investigations on electrochemical CO₂ reduction reaction (eCO2RR) on copper (Cu) provide instructive information for the understanding and development of Cu-based catalysts and thus help improve their eCO2RR selectivity toward desired products. Although most studies on the reaction mechanism rely on computational simulations, experiments conducted on well-defined single-crystal structures are able to effectively mirror the ideal surfaces employed in simulation studies and thus convey insightful knowledge on the structure–performance correlation of Cu catalysts in eCO2RR. This mini-review provides an overview on state-of-the-art development of Cu single crystals and their facet dependency in eCO2RR in the recent years, followed by an outlook and perspective on what can be expected in the future.

对铜（Cu）上电化学CO ₂还原反应（eCO2RR）的研究为理解和开发铜基催化剂提供了指导性信息，从而有助于提高其对所需产物的eCO2RR选择性。尽管大多数关于反应机理的研究依赖于计算模拟，但在明确的单晶结构上进行的实验能够有效地反映模拟研究中使用的理想表面，从而传达有关 eCO2RR 中铜催化剂的结构-性能相关性的深刻知识。 。这篇简短的评论概述了近年来 Cu 单晶的最新发展及其在 eCO2RR 中的晶面依赖性，随后对未来的预期进行了展望和展望。