Catalytic Electrochemical Reduction of CO2 in Ionic Liquid EMIMBF3Cl

A novel ionic liquid EMIMBF 3 Cl that contains a BF 3 Cl − anion has been synthesized. This is the first report of an ionic liquid with a BF 3 Cl − anion. It was found that CO 2 gas can be dissolved and electrochemically reduced at ambient pressure, and room temperature in the ionic liquid EMIMBF 3 Cl. The reduction of CO 2 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 ∼5.7 mA/cm 2 . The BF 3 Cl − anion may catalyze the CO 2 reduction by forming a Lewis acid-base adduct BF 3 -CO 2 .