Highly selective electrocatalytic reduction of CO to HCOOH over an derived Ag-loaded BiOCO electrocatalyst.

The electrochemical reduction of CO to HCOOH is considered one of the most appealing routes to alleviate the energy crisis and close the anthropogenic CO cycle. However, it remains challenging to develop electrocatalysts with high activity and selectivity towards HCOOH in a wide potential window. In this regard, Ag/BiOCO was prepared by an electrochemical transformation from Ag/BiO. The Ag/BiOCO catalyst achieves a faradaic efficiency (FE) of over 90% for HCOOH in a wide potential window between -0.8 V and -1.3 V the reversible hydrogen electrode (RHE). Moreover, a maximum FE of 95.8% and a current density of 15.3 mA cm were achieved at a low applied potential of -1.1 V. Density functional theory (DFT) calculations prove that the high catalytic activity of Ag/BiOCO is ascribed to the fact that Ag can regulate the electronic structure of Bi, thus facilitating the adsorption of *OCHO and hindering the adsorption of *COOH. This work expands the electrochemical derivatization strategy for the preparation of electrocatalysts.