Au atom tailoring of palladium nanocatalysts to boost cathodic 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 nanoparticle alloyed Au single atoms (namely AuPd-x) can achieve 52.3% faradaic efficiency of DMC at 30 mA cm⁻² 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 that are generated by bromine from anodic oxidation of bromide. The electronic modulation of Pd atoms by Au atoms not only speeds up CO₂/CH₃OH-to-CO/CH₃O⁻ conversion but also facilitates Pd⁰-to-Pd²⁺ transition. DFT calculations also confirm that doping Au atoms reduces the energy barrier for the coupling step between *CO and *OCH₃. Our work opens up new opportunities to expedite electrochemical production of DMC from abundant CO₂ and cheap CH₃OH.