The performance of a Ru/SiO2 catalyst for methane steam reforming at 450-550 degrees C is studied in the present. These conditions are suitable for coupling the fixed-bed reactor with a hydrogen-selective membrane for hydrogen recovery, with the subsequent equilibrium shift. A reaction mechanism based on the dissociative adsorption of steam and methane has been proposed (from a total of six possible mechanisms compared), in terms of the statistical analysis of reaction data obtained at different temperatures and contact times in an integral, lab-scale reactor. The proposed model shows that hydrogen inhibition plays an important role in the reaction. Finally, the Ru/SiO2 catalyst prepared in this work is found to be one of the most active catalysts, among other Ru-based catalysts reported in the literature. (C) 2011 Elsevier B.V. All rights reserved.