Efficient Electrocatalytic CO2 Reduction Driven by Ionic Liquid Buffer‐Like Solutions

Abstract Electrocatalysis of CO 2 reduction in aqueous electrolytes containing the ionic liquid (IL) 1‐ n ‐butyl‐2,3‐dimethylimidazolium acetate ([BMMIm][OAc]) and DMSO proceeded at low overpotentials (−0.9 V vs. Ag/AgCl) at commercially‐available Au electrodes, with high selectivity for CO production (58 % faradaic efficiency at −1.6 V vs. Ag/AgCl). 0.43 mol CO 2 per mol IL could be absorbed into the electrolyte at atmospheric pressure, forming bicarbonate and providing a constant supply of dissolved CO 2 to the surface of the electrode. Electrocatalysis of CO 2 reduction in the electrolyte was facilitated by stabilization of CO 2 radical anions by the imidazolium cations of the IL and buffer‐like effects with bicarbonate.