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. The tunable design of molecular catalysts presents opportunities for the control of product selectivity in CO2 reduction, yet to date, complexes capable of producing multicarbon products have been elusive. Here, a Br-bridged dinuclear Cu(I) complex that turns over C3H7OH is reported.