The steady-state kinetics of NO oxidation and its reverse reaction were studied by systematic measurements in an integral reactor at a range of temperatures, reactor pressures and reactant concentrations on a commercial iron zeolite catalyst. A Langmuir-Hinshelwood type rate equation was found to describe the experimental results with very good accuracy. The reaction orders for NO and O-2 were found to be 1 and 0.75, respectively, while the reaction was inhibited by both NO2 and H2O. For the first time, the kinetics developed allow the influence of water vapor on the rate of the NO/NO2 equilibrium reaction both in the concentration range above and below 1 vol% H2O to be described. (c) 2013 Elsevier B.V. All rights reserved.