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 (FEC2+, 89%), partial current density (jC2+, 397 mA cm−2), and energy efficiency for C2+ species (EEC2+, 24%) and total current density (jtotal, up to 1000 mA cm−2) are achieved in membrane electrode assembly (MEA), surpassing most of the reported catalysts for total C2+ products.