The catalytic activity of supported molybdenum carbide was examined versus activation of the carbon support, A mesoporous carbon black composite (CBC) support was used and activated with either HNO3 or H2O2 for 0.5 h. After impregnation and carburisation, the beta-Mo2C hexagonal compact crystallographic phase was obtained as the unique active phase. Several techniques (porosity measurements, X-ray diffraction (XRD), elemental analysis) were used in order to characterise the catalyst's physical properties. The temperature-programmed reduction (TPR) analysis and CO titration performed on these samples underlined an effect of oxidative treatment with H2O2 and HNO3 on the active phase dispersion, The kinetic study of the hydrodenitrogenation (HDN) of indole on these carbon materials-supported molybdenum carbide was improved when the support was activated. (C) 2002 Elsevier Science B.V All rights reserved.