Molecule Doping of Atomically Dispersed Cu–Au Alloy for Enhancing Electroreduction of CO to C2+ Products

Abstract Electrocatalytic carbon monoxide reduction (CORR) is effective in achieving renewable synthesis of valuable C 2+ species from CO. However, the production of C 2+ species is challenged by low activity and selectivity. Here, the surface of the atomically dispersed Cu–Au alloy is functionalized with aromatic heterocycle, thiadiazole derivate (N 2 SN), to enhance the conversion of CO into C 2+ species with acetate as the main product. The N 2 SN functional groups with electron withdrawing property can alternate the oxidization state of copper, as confirmed by XPS and XAS, thus orienting the CORR pathway to the formation of C 2+ /acetate. In situ Raman reveals that the N 2 SN treated sample exhibits stronger signal of *CO intermediate for further dimerization and the C–C–O intermediate relates to acetate formation. Theoretical calculation demonstrates the N 2 SN molecule doping contributes to lowered energy barrier for C–C coupling, improved activity and selectivity to CORR, and suppressed hydrogen evolution reaction. High Faradaic efficiency (FE C2+ , 89%), partial current density ( j C2+ , 397 mA cm −2 ), and energy efficiency for C 2+ species (EE C2+ , 24%) and total current density ( j total , up to 1000 mA cm −2 ) are achieved in membrane electrode assembly (MEA), surpassing most of the reported catalysts for total C 2+ products.