SELECTIVE HYDROGENATION OF CFC-12 TO HFC-32 ON ZR-PD/C CATALYST

Reaction of dichlorodifluoromethane(CFC-12) and chlorodifluoromethane(HCFC-22) with H-2 was carried out on modified Pd catalysts. On 5wt% Pd/C, hydrogenation of CFC-12 gave mainly difluoromethane(HCF-32) at 200 degrees C and methane at 350 degrees C, respectively. Zr and V modifiers promoted to increase in activity with no change in selectivity and, thus, to enhance the yield of HFC-32. From temperature programmed reduction (TPR) measurements, formation of Pd-Zr hydride, which desorbed hydrogen at cn. 200 degrees C, was observed. This hydride may play a role to supply active hydrogen in the reaction at the reaction temperature.