Abstract: The method of hydrodechlorination by palladium catalyst is to remove chlorine atom in chlorofluorocarbon and turn it into the possible substitute pentafluoroethane.The supported palladium on activated carbons was effective catalyst for selective hydrodechlorination of chloropentafluoroethane.The selectiveness to pentafluoroethane reached 99% in hydrodechlorination of chloropentafluoroethane.The catalytic stability and activity of supported palladium in hydrodechlorination were improved when the activated carbon supports were pretreated with concentrated nitric acid.These improvements attributed to the formation of finely dispersed palladium particles.The apparent reaction orders of H2 and chloropentafluoroethane for hydrodechlorination of chloropentafluoroethane were respectively 1/4 and 1/2.