To alleviate the global warming by removing excess CO₂ and converting them into value-added chemicals, (photo)electrochemical reduction has been recognized as a promising strategy. As the CO₂ reduction reaction (CO₂RR) is involved with multiple electrons and multiple products, plus the complexity of the surface chemical environment of the catalyst, it is extremely challenging to establish the structure/function relationship. Atomically precise metal nanoclusters (NCs), with crystallographically resolved structure, molecule-like characters and strong quantum confinement effects, have been emerging as a new type of catalyst for CO₂RR, and more importantly, they can provide an ideal platform to unravel the comprehensive mechanistic insights and establish the structure/function relationship eventually. In this review, the recent advances regarding employing molecular metal NCs with well-defined structure including Au NCs, Au-based alloy NCs, Ag NCs, Cu NCs for CO₂RR and relevant mechanistic studies are discussed, and the opportunities and challenges are proposed at the end for paving the development of CO₂RR by using atomically precise metal NCs.

为了通过去除过量的CO ₂并将其转化为增值化学品来缓解全球变暖，（光）电化学还原已被认为是一种有前途的策略。由于CO ₂还原反应（CO ₂ RR）涉及多个电子和多种产物，再加上催化剂表面化学环境的复杂性，建立结构/功能关系非常具有挑战性。具有晶体学上解析的结构，类分子特征和强大的量子约束效应的原子精确的金属纳米簇（NCs）已经成为一种新型的CO ₂催化剂RR，更重要的是，它们可以提供一个理想的平台，以阐明综合的机械原理并最终建立结构/功能关系。在这篇综述中，讨论了关于使用具有明确结构的分子金属NC的最新进展，包括用于CO ₂ RR的Au NCs，Au基合金NCs，Ag NCs，Cu NCs以及相关的机理研究，并提出了机遇与挑战最后通过使用原子精确的金属NC为CO ₂ RR的发展铺平了道路。