Different effects of support hydrophilicity and metal-oxide on the performance of Pt-based catalysts were investigated with the aim of improving the mass activities toward methanol electrooxidation. Both potentiodynamic and potentiostatic measurements revealed that improved surface hydrophilicity of multi-wall carbon nanotubes (MWCNTs) could promote the dispersion of Pt nanoparticles and, consequently, promote the Pt utilization and reduce the polarization in methanol electrooxidation. In addition, WO3 was shown to play a supportive role in enhancing catalytic activity. The interaction between Pt and WO3 was examined by CO-stripping and CO oxidation transient experiments. The results suggested that the activity and the kinetics of monolayer COads electrooxidation of Pt nanoparticles are enhanced by the adjacent WO3 via a bifunctional mechanism, which accounts for improved activity in methanol electrooxidation.