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 on 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 rangeof 423–523 K. The main products were CH2F2 and CH 4. Ethane could be detected at higher temperatures. Lower deactivation ratesand a higher activation energy for CH2F2 formation were foundfor Pd(111). In a comparison to our previous results with dichlorotetrafluoroethane (CFC-114a), the hydrodechlorination rate of CCl 2F2 was 2 orders of magnitude lower, the mono-dechlorinated product (CHClF2) was not produced, and the bulk palladium hydrogen activity was not detected. An overview of the hydrodechlorination reaction is presented.