Hydrodenitridation of indole over undoped and potassium doped (0-01-1 Wt-%) Mo2C catalysts was studied at 573 K under a pressure of 50 atm and contact times ranging from 0.03 to 0.7 s. The measured concentration profiles of indole, o-ethylaniline, ethylcyclohexane and ethylbenzene were successfully analyzed in terms of a kinetic model derived from two doubly coupled cycles, with early and late denitrogenation steps, in the whole range of the investigated contact times. The influence of potassium on the determined rate constants and the selectivity to aromatics vs. cycloparaffines was quantified and briefly discussed. (C) 2004 Elsevier B.V. All rights reserved.