Abstract:
PURPOSE: Provided is a palladium catalyst which is used in a dehydrochlorination reaction such as changing HCFC to HFC. Presented also are the catalyst and the reaction conditions that bring about the high yield at low temperature and maintain the activity and the selectivity for a long period of time. CONSTITUTION: The preparation method of the catalyst and reaction method comprise: continuously treating activated carbon with aqueous solutions of HF and HCl and dipping palladium into it; reducing the above catalyst with hydrogen at 200-300°C before the dehydrochlorination reaction; and making 1,1-difluoroethane from 1,1-difluoro-1-chloroethane using the above catalyst(Pd/C) by dehydrochlorination reaction at 240-300°C and feeding 1,1-difluoro-1-chloroethane and hydrogen gas in a ratio of 2-6.
Abstract:
PURPOSE: Disclosed are a palladium catalyst supported on active carbon, a preparation method thereof and a hydrogenation reaction of chlorofluorocarbon to hydrofluorocarbon using the prepared catalyst. CONSTITUTION: The active carbon used as catalyst support is pretreated with a basic solution of 0.2-1M NaOH at 60-80deg.C for 1-5hours two or five times. And the acid treatment of a hydrochloric acid may be also conducted whenever after the base treatment or the hydrogen fluorine treatment or before loading of palladium species. The palladium species is impregnated by the adsorption precipitation method or the co-precipitation method. The hydrogenation reaction, dehalogenation, of chlorofluorocarbon to hydrofluorocarbon is selectively preformed to increase the yield of HFC-32.