Pd, Ni, Pt supported on TiO2 were effective for hydrodechlorination of CFC 113. The reaction took place at >150°C and C2H2F2, C2F3C1 and C2H2F2 and C2H3F3 were formed over the catalysts, respectively. C2F3C1 was formed over Co/Ti02 at 350 °C and the same reaction took place over MnTiO3 at >500°C. Pd/C tends to substitute hydrogen atoms for chlorine atoms so that CF2HCFH2 was formed from CFC 113 with high selectivity of more than 85%. The activities of Rh/C and Pt/C were smaller than that of Pd/C. The addition of 2 mol% of water vapor did not affect the reaction but supressed the formation of CH4 and promoted the formation of CO at>300°C. Plots of the catalytic activity against the heat of formation of metal chlorides gave a volcano shape. This suggests that the reaction proceeded via chlori-nation and dechlorination of the catalyst surface. MnTi03 was so stable that XRD pattern decreased slightly in intensity after the CFC 113-H2 reaction for 25 h at 550 °C. The structure of Cr2O3 was not changed after the reaction at 350 °C for 20 h by XRD.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)