Abstract: The invention is a process for the purification of hydrogen chloride formed during the thermal cracking of 1,2-dichloroethane, by hydrogenating the acetylene impurities with excess hydrogen, at pressures of from 8 to 20 bar absolute and at temperatures of from 120.degree. to 180.degree. C., using platinum or palladium supported catalysts, wherein, according to the invention, carrier materials having a specific surface area of not more than 5 m.sup.2 /g are used, the hydrogen excess used is a function of the acetylene content, the gas mixture, after reaching a temperature of approximately 70.degree. C., is permitted a dwell time of not more than 0.8 second before it enters the catalyst, and the temperature, pressure and volume flow rates are dependent on one another within narrow limits.The purified hydrogen chloride is used for oxychlorination.