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 C₂₊ species from CO. However, the production of C₂₊ 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 (N₂SN), to enhance the conversion of CO into C₂₊ species with acetate as the main product. The N₂SN 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 C₂₊/acetate. In situ Raman reveals that the N₂SN 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 N₂SN 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 C₂₊ 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 C₂₊ products.