Electrochemical Hydrogenation of CFC-13 Using Metal-Supported Gas Diffusion Electrodes

Chlorofluorocarbons(CFCs) are known to cause the depletion of the ozone layer at the stratosphere. A large amount of CFCs still in use should be collected and retreated to harmless compounds to the environment. Electrochemical hydrogenation of CFC-13 (CClF 3 ), which is the most stable of the C1 chlorofluorocarbons, was attempted with 13 kinds of metal-supported porous carbon gas diffusion electrodes (GDEs). In the case of the electrolysis at a Cu-supported GDE, both dechlorination and defluorination of CFC-13 proceeded, and methane was produced. With a Ag-supported GDE, dechlorination proceeded selectively, and HFC-23 (CHF 3 ) was produced. The faradaic efficiency for hydrogenation of CFC-13 depends on the current density, the pressure of CFC-13, the composition of the electrolyte solution, and the potential imposed on the GDE. If these factors are optimized, the faradaic efficiency for hydrogenation of CFC-13 was improved up to 77.7%.