Metal nitride catalysts have received extensive attention because of their potential high performance for hydrodesulfurization (HDS). In the present study, highly dispersed Mo nitride clusters having a composition of Mo2N are synthesized in zeolite pores by means of a CVD method using MO(CO)(6) as a precursor. The catalytic properties of the molybdenum nitride catalysts for the HDS of thiophene are compared with that of an intrazeolite molybdenum sulfide catalyst. The molybdenum nitride catalyst shows a more stable thiophene HDS activity than the molybdenum sulfide catalyst. Molybdenum nitride clusters are only partially sulfided even after a prolonged HDS reaction. (C) 2003 Elsevier B.V. All rights reserved.