Ionic liquid-based electrolytes for CO electroreduction and CO electroorganic transformation.

CO is an abundant and renewable C1 feedstock. Electrochemical transformation of CO can integrate CO fixation with renewable electricity storage, providing an avenue to close the anthropogenic carbon cycle. As a new type of green and chemically tailorable solvent, ionic liquids (ILs) have been proposed as highly promising alternatives for conventional electrolytes in electrochemical CO conversion. This review summarizes major advances in the electrochemical transformation of CO into value-added carbonic fuels and chemicals in IL-based media in the past several years. Both the direct CO electroreduction (COER) and CO-involved electroorganic transformation (COEOT) are discussed, focusing on the effect of electrocatalysts, IL components, reactor configurations and operating conditions on catalytic activity, selectivity and reusability. The reasons for the enhanced CO conversion performance by ILs are also discussed, providing guidance for the rational design of novel IL-based electrochemical processes for CO conversion. Finally, the critical challenges remaining in this research area and promising directions for future research are proposed.