at least one platinum group metal these metals being deposited on a support even at low operating temperatures excellent degrees of conversion and selectivities for fluoroethylenes and or chlorofluoroethylenes are obtained application_number US 78838891 A description the subject of the invention is hence a process for the manufacture of fluoroethylenes and or chlorofluoroethylenes by catalytic hydrogenolysis of a chlorofluoroethane of general formula str1 in which at least one of the symbols x x 39 y and y 39 represents a fluorine atom and the others which may be identical or different each represent a hydrogen or chlorine atom or of a chlorofluoroethylene of general formula str2 in which at least one of the symbols x x 39 and y represents a fluorine atom and the others which may be identical or different each represent a hydrogen or chlorine atom characterised in that a mixed catalyst based on copper or silver and on at least one platinum group metal preferably palladium is used these metals being deposited on a support in the mixed catalyst according to the present invention the copper and or silver content can range from 1 to 20 by weight and preferably between 3 and 15 and that of.