Catalytic Electrochemical Reduction of CO2 in Ionic Liquid EMIMBF3Cl

A novel ionic liquid EMIMBF3Cl that contains a BF3Cl- anion has been synthesized. This is the first report of an ionic liquid with a BF3Cl- anion. It was found that CO2 gas can be dissolved and electrochemically reduced at ambient pressure, and room temperature in the ionic liquid EMIMBF3Cl. The reduction of CO2 occurred at a relatively less negative electrode potential of -1.8 V vs. silver wire, compared to previous reported values that are between -2.4 and -2.0 V. The reduction current density can be as high as similar to 5.7 mA/cm(2). The BF3Cl- anion may catalyze the CO2 reduction by forming a Lewis acid-base adduct BF3-CO2. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3606487] All rights reserved.