Electrochemical reduction of supercritical carbon dioxide in ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate

Using 1-n-butyl-3-methylimidazolium hexafluorophosphate, (BmimPF(6)) as a solvent and electrolyte, supercritical (SC) CO2 and water were successfully electrolyzed, and the products were CO, H-2, and small amount of formic acid. The Faradic efficiency (FE) of CO increases considerably as the pressure is increased. In contrast, the FE for H-2 decreases as the pressure Of CO2 rises. After the electrolysis, the products were extracted with SC CO2 and the BmimPF(6) could be reused. This offers a new and clean route to use SC Co-2. (C) 2004 Elsevier B.V. All rights reserved.