Temperature Effects on CO₂ Electroreduction Pathways in an Imidazolium-Based Ionic Liquid on Pt Electrode

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 CO 2 in 1-ethyl-3methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim]-[NTf 2 ]) and compared them with those in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([Bmpy][NTf 2 ]) by electrochemical methods and density functional calculations. We summarize the crucial factors determining the reaction pathways for electroreduction of CO 2 in [Emim][NTf 2 ]. 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.

Optimization Strategies for Selective CO2 Electroreduction to Fuels

“…Zhan et al [143] fabricated an imidazolium-Pt catalytic system and found that CO 2 RR in ILs is affected by temperature (Fig. 12).…”

“…CO 2 reduction on the imidazolium-Pt surface at different temperatures. Reproduced with permission from Ref [143]…”

Electrical Double Layer Structure in Ionic Liquids and Its Importance for Supercapacitor, Battery, Sensing, and Lubrication Applications

“…80 Zhan et al showed that the more densely packed EDL of [C 2 mim][TFSI] in an electric field shows a higher capacitance compared to the less densely packed EDL of [C 4 mpyrr][TFSI]. 81 They showed that changes in temperature can alter the behavior of the EDL in the presence of an analyte, such as carbon dioxide (CO 2 ). For the electrochemical reduction of CO 2 in [C 2 mim][TFSI], five different reaction pathways are possible.…”

“…For the electrochemical reduction of CO 2 in [C 2 mim][TFSI], five different reaction pathways are possible. 81 Variations in temperature can therefore be used to tune the reaction pathway because of the alteration of the EDL at the IL/ electrode interface.…”

“…The authors suggested establishing a conditioning potential of 0 V before each measurement for oxygen detection to ensure a consistent and stable IL/electrode interface . Zhan et al showed that the more densely packed EDL of [C 2 mim]­[TFSI] in an electric field shows a higher capacitance compared to the less densely packed EDL of [C 4 mpyrr]­[TFSI] . They showed that changes in temperature can alter the behavior of the EDL in the presence of an analyte, such as carbon dioxide (CO 2 ).…”