Electrocatalytic conversion of carbon dioxide to fuels: a review on the interaction between CO2 and the liquid electrolyte

The electrochemical reduction of carbon dioxide using renewable energy resources can potentially accomplish the carbon-neutral energy cycle while synthesizing fuels simultaneously. CO2 electrocatalysis typically requires the presence of protons in a liquid electrolyte, which acts as a possible cocatalyst for CO2 conversion to fuels. However, the following fundamental questions remain: (1) How does the interaction between CO2 and liquid electrolyte influence CO2 electrocatalysis? (2) How does the selectivity toward products from CO2 reduction depend upon the choice of electrolyte? In this review article, we emphasize on the interaction between CO2 and the liquid electrolyte, in order to find answers to these questions. Specifically, the nature of interactions along with the structures of solvated molecules for CO2 in water, organic solvents and ionic liquids are discussed. Finally, relevant questions are proposed which need to be studied carefully in order to gain a deeper understanding of CO2 electrocatalysis. (C) 2017 John Wiley & Sons, Ltd.