Electrochemical CO2-to-CO via enriched oxygen vacancies at gold/ceria interfaces

Abstract

The carbon dioxide electroreduction reaction (CO₂RR) to carbon monoxide (CO) is a promising avenue to store renewable energy. Gold (Au) is a critical component of catalysts for CO production in the CO₂RR. Still, the high cost of Au together with the low mass activity hinders its potential towards practical CO₂RR application. Here we report a strategy of catalyst design, oxygen vacancy modulation via controlling Au/ceria interface structures, to promote Au mass activity for CO production (j_CO,mass) in the CO₂RR. Through ceria-nanocube-supported Au nanoparticle fabrication, we construct Au/CeO₂{100} interfaces with high concentration of oxygen vacancies facilitating CO₂ adsorption and activation. We achieve, at 200 mA cm⁻², a record j_CO,mass of 678 mA mg_Au⁻¹ in the CO₂RR, a 1.3× improvement relative to the best prior reports.