The purpose of this work was to investigate the difference between the experimental molar fractions of products obtained during the evaluation of Pt, Co and Ni/Hydrotalcites-WOx catalysts and the calculated composition in equilibrium for the ethanol steam reforming reaction. Mole fractions of H-2, CO2, CH3CHO, CH2CH2, CH4 and H2O were calculated using the stoichiometric and the minimization of the Gibbs free energy methods. The difference between calculated and experimental mole fractions was used to determine the intermediate and final compounds in the reaction mechanism and also how close to equilibrium are the reactants and final products. In addition, by comparing H-2 and the conversion, it was possible to distinguish which series of catalysts were more active. From our experimental results, the conversion order of these catalysts was as follows: Pt > Ni > Co and the reaction rate per g-atm of metal was: Pt >> Ni approximate to Co. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.