Freon electrochemistry in room-temperature ionic liquids

The reductive electrochemical activation of three C2 freons, and one C1 freon, in four different room temperature ionic liquids (RTILs), is reported. Electrochemistry was performed using glassy carbon (GC), platinum and silver cathodes. The apparent reduction potentials for the freons ranged from -1.0 V vs. Pt to -2.8 V vs. Pt, depending on the freon structure, cathode material and RTIL medium. Discharge potentials were found to be distinctly more cathodic in RTIL media, relative to organic solvents (dimethylformamide), due to the significant ohmic loss within the cell as a consequence of the viscous nature of the RTIL media. Similarly, cathodic currents were greatly suppressed in RTILs due to low mass transport rates. The electrocatalytic nature of Ag cathodes is maintained in RTIL media with some systems exhibiting over 1 V reduction in discharge potentials. (c) 2006 Elsevier B.V. All rights reserved.