The present study is focused in the use of core shell molybdenum substrates as supports for Pt electrocatalysts. These substrates are prepared by the carbothermal-reduction method and present a core shell structure, with a reduced-Mo core (Mo2C, MoO2 and/or Mo-0) and a MoO3 shell. Kinetic and mechanistic studies were performed through potentiodynamic and potentiostatic experiments for carbon monoxide and methanol oxidation reactions on Pt/X@MoO3/C (X = MO2C, MoO2, Mo-0) catalysts in an intermediate temperature range (20 < T < 70 degrees C). Results reveal the promoter effect and the great stability of Mo-carbide based substrates for both reactions in the temperature range studied. Carbon monoxide and methanol oxidation on Pt/X@MoO3/C are enhanced by a facile oxygenated species formation, better dispersion of the active phase and electronic effects. It is concluded that the best catalyst performance during the methanol oxidation reaction was obtained with the substrate that contains only MO2C-phase in its core. (C) 2013 Elsevier B.V. All rights reserved.