Electrochemical oxidation and reduction, with clean power, are key to energy conversion and storage. For example, electrochemical oxidation is a determining step for fuel cells, combination of electrochemical oxidation and reduction can form a metal-air battery. Electrochemical oxidation and reduction make significant contributions to prepare valuable chemicals directly and improve yield efficiency and reduce the three wastes, which have become one of the green methodologies. Ionic liquids have attracted increasing attentions in the area of electrochemistry due to their significant properties including good chemical and thermal stability, wide liquid temperature range, considerable ionic conductivity, nonflammability, broad electrochemical potential window and tunable solvent properties. Up to now, abundant studies of ionic liquids have reported for their practical applications for electrochemical reactions. This review covers recent studies on the applications of ILs as green and universal replacements for the traditional reagents in electrochemical oxidation and reduction. The adaptabilities of ILs in these reactions are predicted as a solution to the problems of conventional electrochemical processes and to become a powerful method in electrochemical oxidation and reduction.

Nan Yao and Yu Lin Hu