Molecular metal complex catalysts are highly tunable in terms of their CO₂ reduction performance by means of their flexible molecular design. However, metal complex catalysts have challenges in their structural stability and it has not been possible to synthesize high-value-added C₃ products due to their inability to perform C–C coupling. Here we show a CO₂ reduction reaction catalysed by a Br-bridged dinuclear Cu(I) complex that produces C₃H₇OH with high robustness during the reaction. The C–C coupling reaction mechanism was analysed by experimental operando surface-enhanced Raman scattering analysis, and theoretical quantum-chemical calculations proposed the formation of a C–C coupling intermediate species with substrate incorporation between the two Cu centres. Molecular design guidelines based on this discovery offer an approach to developing next-generation catalysts that generate multicarbon CO₂ reduction products.

分子金属络合物催化剂通过其灵活的分子设计在其CO ₂还原性能方面具有高度可调性。然而，金属配合物催化剂在结构稳定性方面存在挑战，并且由于无法进行C-C偶联而无法合成高附加值的C ₃产品。在这里，我们展示了由 Br 桥联双核 Cu(I) 配合物催化的CO ₂还原反应，该反应在反应过程中产生具有高鲁棒性的C ₃ H ₇ OH。通过实验操作表面增强拉曼散射分析对 C-C 偶联反应机理进行了分析，理论量子化学计算提出了在两个 Cu 中心之间掺入底物的 C-C 偶联中间体的形成。基于这一发现的分子设计指南提供了一种开发产生多碳CO ₂还原产物的下一代催化剂的方法。