Hydrodehalogenation with Mo₂C and W₂C

As part of ongoing studies concerned with heterogeneous catalysis over sonochemically prepared catalysts, the activity, selectivity, and stability of sonochemically prepared Mo₂C and W₂C in hydrodehalogenation (HDH) of several halogenated organics were studied. The HDH of aryl halides with Mo₂C led exclusively to benzene. With the exception of C₆H₅F, the activity of W₂C was greater than Mo₂C and followed a similar pattern. The catalysts were active at ambient pressure and low temperatures. No hydrogenation products were observed despite the high hydrogen/substrate ratio. Methane was the major observed product for the HDH of CFC with sonochemically prepared Mo₂C. The rate increased with temperature and the selectivity was temperature independent. The activity of Mo₂C was greater towards fluorocarbons while the activity of W₂C was greater for chloro-, bromo-, and iodocarbons.