Oxidative steam reforming of methanol (OSRM) mixed with hydrogen peroxide was investigated as a compact hydrogen source for mobile fuel cell systems and a catalytic reactor was designed to validate the concept. The catalytic decomposition of hydrogen peroxide released the heat, oxygen and water vapor, all of which served OSRM. As the heat was generated internally by the decomposition of the liquid hydrogen peroxide, the reactor ran without external supply of heat and vaporizers for liquid reactants. The platinum/yAl(2)O(3) catalyst was used, because Pt was active in the decomposition of hydrogen peroxide as well as methanol reforming. The optimal operation condition was determined from the parametric study of H2O2/CH3OH mixture ratios of the liquid reactant supplied to the reforming reactor. The concentration of hydrogen peroxide at 70 wt% was selected to avoid detonation of its mixture with organic substance such as alcohol. The reforming performance was best among the test conditions when the mixture ratio of 70 wt% H2O2/CH3OH was 3.036. The investigation demonstrated the proposed concept of methanol reforming is effective alternative to the existing OSRM without auxiliary reactors for treatment of reactants and external heat supply. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.