This work deals with the catalytic behavior of a series of Sn-Mo-O catalysts in the partial oxidation of methanol. The catalysts of different Sn:Mo ratios, were prepared by co-precipitation and they were investigated by means of dynamic experiments, test reactions (methanol-formaldehyde partial oxidation. isopropyl alcohol decomposition) and physico-chemical characterization (XRD, BET, TPD of NH3. TPR, XPS and EPR). It was observed that interdispersion between MoO3 and SnO2 favors a superficial architecture in which the Sn-Mo interaction plays a major role modifying the reactivity of the lattice oxygens and the reducibility of Mo ions and, therefore, the catalytic behavior. The partial oxidation of methanol induces a reordering of the catalyst structural organization leading to a Mo surface enrichment. The absence of chemical shifts for Sn (XPS) suggests that the O-Mo bond is mainly responsible fur the methanol reaction.