Pt and Pt-Ru alloys with several Pt/Ru ratios supported on carbon (Vulcan) were prepared using high-intensity ultrasound by reduction of H2PtCl6 and RuCl3 precursors in an aqueous solution. This method of catalyst preparation was performed in absence of any surfactant or organic addictive. The particles formed were characterized by X-ray diffraction (XRD), energy dispersive X-ray (EDX) and transmission electron microscopy (TEM). From the XRD studies, a decrease of metal particle size and of the lattice parameters was observed with the increase of the Ru content. The electroactivities were tested for the methanol oxidation reaction in acid electrolyte, and it was found that Pt-Ru catalysts were more activity than pure Pt. (C) 2007 Elsevier Ltd. All rights reserved.