Au Atom Tailoring of Palladium Nanocatalysts to Boost Cathodically Coupling of Carbon Dioxide and Methanol into Dimethyl Carbonate

Abstract

Industrial production of dimethyl carbonate (DMC) suffers from harsh conditions. Electrochemical coupling of carbon dioxide and methanol at the cathode offers a promising approach but yet lacks efficient electrocatalysts. Herein, we report that palladium nanoparticles alloyed Au single atom (namely AuPd-x) can achieve 52.3% faradaic efficiency of DMC at 30 mA/cm2 in a methanol solution containing NaBr. Control experiments disclose that AuPd-x reduces CO2 and CH3OH into CO and CH3O- followed by instant coupling into DMC promoted by the surface Pd2+ species generated by bromine from anodic oxidation of bromide. The electronic modulation of Pd atoms by Au atom not only speeds up the CO2/CH3OH-to-CO/CH3O- conversion but also facilitates Pd0-to-Pd2+ transition. DFT calculations also confirm that doping Au atom reduces the energy barrier for the coupling step between *CO and *OCH3. Our work opens up new opportunities to expediate electrochemical production of DMC from abundant CO2 and cheap CH3OH.