hydrodechlorination of Dichlorodifluoromethane over Palladium Model Catlaysts and a Compariosn with the Hydrodechlorination of 1,1-Dichlorotetrafluoroethane

摘要

The hydrodechlorinaiton 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 abatch reactor, at atmospheric pressure and in the temperature range of 423-523 K. The main products were CH_F_2 and CH_4. Ethane could be detected at higher temperatures. Lower deactivation rates and a higher activation energy for CH_2F_2 formation were found for Pd(111). In a comparison to our previous results with dichlorotetrafluoroethane (CFC-114a), the hydrodechlorination rate of CCl_2F_2 was 2 orders of magnitude lower, the mono-dechlorinated product (CHCIF_2) was not produced, and the bulk palladium hydrogen activity was not detected. An overview of the hydrodechlorination reaction is presented.