Electrocatalytic CO₂ reduction into value-added multicarbon products offers a means to close the anthropogenic carbon cycle using renewable electricity. However, the unsatisfactory catalytic selectivity for multicarbon products severely hinders the practical application of this technology. In this paper, we report a cascade AgCu single-atom and nanoparticle electrocatalyst, in which Ag nanoparticles produce CO and AgCu single-atom alloys promote C-C coupling kinetics. As a result, a Faradaic efficiency (FE) of 94 ± 4% toward multicarbon products is achieved with the as-prepared AgCu single-atom and nanoparticle catalyst under ~720 mA cm⁻² working current density at −0.65 V in a flow cell with alkaline electrolyte. Density functional theory calculations further demonstrate that the high multicarbon product selectivity results from cooperation between AgCu single-atom alloys and Ag nanoparticles, wherein the Ag single-atom doping of Cu nanoparticles increases the adsorption energy of *CO on Cu sites due to the asymmetric bonding of the Cu atom to the adjacent Ag atom with a compressive strain.

将CO ₂电催化还原为增值多碳产品提供了一种利用可再生电力来关闭人为碳循环的方法。然而，多碳产物的催化选择性不理想，严重阻碍了该技术的实际应用。在本文中，我们报道了一种级联AgCu单原子和纳米颗粒电催化剂，其中Ag纳米颗粒产生CO，AgCu单原子合金促进CC耦合动力学。结果，在流通池中，在-0.65 V、 ~720 mA cm ^-2工作电流密度下，使用所制备的 AgCu 单原子和纳米粒子催化剂，对多碳产品实现了 94 ± 4% 的法拉第效率 (FE)用碱性电解液。密度泛函理论计算进一步表明，高多碳产物选择性是由AgCu单原子合金和Ag纳米颗粒之间的合作产生的，其中Cu纳米颗粒的Ag单原子掺杂由于不对称键合增加了*CO在Cu位点上的吸附能Cu 原子与相邻 Ag 原子之间的压缩应变。