Temperature Effects on CO<sub>2</sub> Electroreduction Pathways in an Imidazolium-Based Ionic Liquid on Pt Electrode
Tianrong Zhan, Anil Kumar, Michael D. Sevilla, Arun Sridhar, Xiangqun Zeng
Abstract
Ionic liquids (ILs) are thermally stable at both high and low temperatures, making them excellent solvents and electrolytes in extreme ambient conditions. In this work, we systematically studied the temperature effects on the various pathways of electrochemical reduction of CO2 in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][NTf2]) and compared them with those in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Bmpy][NTf2]) by electrochemical methods and density functional calculations. We summarize the crucial factors determining the reaction pathways for electroreduction of CO2 in [Emim][NTf2]. Our results show that temperature can be used to modulate the reaction pathway of electrochemical reduction of carbon dioxide in this imidazolium-based IL via the effects on (i) the mass transport of the reactant and intermediates, (ii) the adsorption and solubility of the intermediates species, and (iii) the IL–electrode interface structure and properties.