CO3MO3C, Co6Mo6C and MCM41-supported Co3Mo3C catalyst are prepared by a simple one-step thermal decomposition method without the conventional temperature-programmed carburization. The resultant carbides are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscope (HRTEM) and BET surface area measurements. The as-prepared Co3Mo3C/MCM41 catalyst exhibits good performance in both probe reactions of hydrodesulfurization (HDS) and hydrodenitrogenation (HDN), which proves the one-step decomposition method to be an effective route for the preparation of bimetallic carbide catalyst. (c) 2007 Elsevier B.V. All rights reserved.