Electrocarboxylation in ionic liquids

Four drivers have stimulated recent research into the electrochemical conversion of carbon dioxide into fuels and chemicals. (1) The prospect of using gaseous CO₂, a gas previously considered a useless waste product, as an economical and abundant source of carbon. (2) The urgent need for effective energy storage technology. (3) The versatility of electrochemical methods. (4) Concern about the rising levels of CO₂ in the atmosphere. Within this thriving research field, one area that has received significant attention and provides the focus of this review is the electrocarboxylation of organic compounds. Electrocarboxylation occurs when a reactive radical anion generated electrochemically from an organic substrate (or CO₂) reacts with CO₂ (or an organic substrate) to form a carboxylate. However, the high reactivity of the electrogenerated reactant means many factors can influence the reaction pathway, particularly the nature of the solvent and electrode. Special attention is given in this review to the use of ionic liquids in electrocarboxylation because these neoteric solvents provide promising alternatives to organic molecular solvents. Finally, some perspectives on potential industrial application of ionic liquids in electrocarboxylation are provided.