Dinuclear Cu(I) molecular electrocatalyst for CO₂-to-C₃ product conversion

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.