A kinetic study of the reduction of NO by n-octane performed isothermally (200 degrees C) at steady state conditions over an active Ag/alumina catalyst was carried out in the presence of hydrogen. The mathematical model was based on a supposed reaction mechanism, which among other steps includes molecular adsorption of NO and CO as well as dissociative adsorption of H-2 and O-2. Formation of CO2 is assumed to go through oxidation of CO. A comparison between experimental data and simulations revealed that the developed mathematical model is able to describe the observed reduction of NO in presence of H2 sufficiently well. (c) 2006 Elsevier B.V. All rights reserved.