A nanostructured electrode, fabricated by means of a co-sputtering method, consisting of Pt nanophases of polycrystalline structure and amorphous tantalum oxide was characterized by transmission electron microscopy, x-ray. diffraction, and x-ray photoelectron spectra analysis. The Pt nanostructured electrode showed excellent performance, that is, much higher current density of methanol electro-oxidation, compared to a typical Pt thin-film electrode. The origin of the enhanced performance in the nanostructured electrode appears to be due to an increased surface area of Pt catalyst in the porous oxide matrix, used as a support for the Pt nanophases and a pathway for transporting methanol as a fuel and protons. (C) 2004 American Vacuum Society.