A process is disclosed for the conversion of halogenated methanes of the formula CCl.sub.y H.sub.2-y F.sub.2 (wherein y is 1 or 2) to a mixture of conversion products. The process involves reacting certain halogenated hydrocarbon feeds and hydrogen (wherein said halogenated methanes are at least one mole percent of the halogenated hydrocarbon feed) in a reaction vessel of alumina, silicon carbide or at least one metal selected from gold, chromium, aluminum, molybdenum, titanium, nickel, iron, cobalt, and their alloys at a temperature of from about 500.degree. C. to 800.degree. C. and a pressure from abut 101 kPa to 7000 kPa to produce a mixture of conversion products of said halogenated methanes which comprises at least 5 mole percent C.sub.2 H.sub.2 F.sub.4, wherein the mole ratio of CH.sub.2 FCF.sub.3 to CHF.sub.2 CHF.sub.2 in said C.sub.2 H.sub.2 F.sub.4 is at least about 1:9.