Selective Electroreduction of Carbon Dioxide to Formic Acid on Cobalt-Decorated Copper Thin Films

The development of highly efficient, selective, and economic approaches for electrochemical reduction of carbon dioxide to hydrocarbons is a promising way to promote the sustainable carbon cycle nowadays. Here, a stable cobalt-decorated copper catalyst is reported with significantly enhanced selectivity toward formic acid produced from CO₂ through electrochemical reduction. This catalyst is prepared through the electrodeposition of cobalt on the surface of copper, followed by Ar and air atmosphere treatment. The as-prepared catalyst exhibits selective conversion of CO₂ to formic acid with a Faradaic efficiency (FE) of ≈80% at an applied potential of −0.65 V versus reversible hydrogen electrode. Meanwhile, the copper electrode treated with the same conditions without cobalt decoration and the cobalt-decorated copper electrode without Ar treatment process only show an FE toward formic acid of ≈56% and ≈57% from CO₂ reduction, respectively. This study represents a facile decoration method to prepare highly selective electrocatalysts for the efficient reduction of CO₂ to value-added chemicals in aqueous electrolytes.