We have studied the preparation of unsupported and lignite supported β-Mo 2 C using MoCl 5 as precursor. The catalysts were characterized by XRD and TEM techniques and tested in the reaction of propene hydrogenation at room temperature and pressure. Total carburization was observed at 923K and although incomplete, carburization also occurred at 473 or 723K. The high temperature supported carbide exhibited a remarkable lifetime in the test reaction (72h), whereas, the massive carbide rapidly deactivated (<1h). The low temperature carburized catalysts also rapidly deactivated (10min). However, in a remarkable way, processing of the used catalysts by H 2 at 723 or 873K, not only restored the initial activity, but increased their stability with time on stream (3 and >24h, respectively). The correlation between the degree of carburization, dispersion and catalyst stability is discussed.