Hydrodechlorination of dichlorodifluoromethane over palladium model catalysts and a comparison with the hydrodechlorination of 1,1-dichlorotetrafluoroethane

The hydrodechlorination of dichlorodifluoromethane (CFC-12) was performed o n small surface area model catalysts, including Pd(111) and Pd(110) single crystals and polycrystalline palladium foil. Reactions were performed in a batch reactor, at atmospheric pressure and in the temperature range of 423- 523 K. The main products were CH2F2 and CH4. Ethane could be detected at hi gher temperatures. Lower deactivation rates and a higher activation energy for CH2F2 formation were found for Pd(111). In a comparison to our previous results with dichlorotetrafluoroethane (CFC-114a), the hydrodechlorination rate of CCl2F2 was 2 orders of magnitude lower, the mono-dechlorinated pro duct (CHCIF2) was not produced, and the bulk palladium hydrogen activity wa s not detected. An overview of the hydrodechlorination reaction is presente d. (C) 2000 Academic Press.