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

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 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 vacancies modulation via controlling Au/ceria interface structures, to promote Au mass activity for CO production (j_CO,mass) in CO₂RR. Through ceria-nanocubes-supported Au nanoparticles 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 mgAu^–1 in CO₂RR, a 1.3× improvement relative to the best prior reports.