the invention provides an economic process for the manufacture of 1 , 3 , 3 , 3 - tetrafluoropropene by a two stage process . a vapor phase hydrofluorination of 1 - chloro - 3 , 3 , 3 - trifluoropropene into 1 - chloro - 1 , 3 , 3 , 3 - tetrafluoropropane and / or 1 , 1 , 1 , 3 , 3 - pentafluoropropane is conducted , followed by the thermal dehydrochlorination of hcfc - 244fa and dehydro fluorination of hfc - 245fa into hfo - 1234ze in the presence of a catalyst which comprises one or more of alkali metal halides , alkaline earth metal halides , halogenated metal oxides , zero oxidation state metals , zinc halides , palladium halides , and activated carbon .