Electrochemical reduction of carbon dioxides to carbon monoxide at a gold electrode in aqueous potassium hydrogen carbonate

Abstract

CO2 is electrochemically reduced to CO in 0.5 M aqueous KHCO3 solution at a gold electrode at 18°C, the reaction proceeding with markedly low overvoltage, starting at –0.8 V vs. normal hydrogen electrode (N.H.E.); the faradaic efficiency for CO formation is 91% at –1.10 V vs. N.H.E. with a partial current of 3.7 mA cm–2, and the reaction probably proceeds via adsorbed intermediates.