Carbon supported Pt1Ru1Irx (0 <= x <= 2) nanoparticles were prepared by it compare nation reductive pyrolysis method and their electrocatalytic activity toward methanol electro-oxidation at 25, 40, and 60 degrees C was investigated. The mass activity (current normalized by the mass of Pt) for methanol electro-oxidation increased as it function of Ir coefficient and cell temperature. Despite the increase in methanol electro-oxidation activity, the addition of Ir does not affect the CO tolerance of the ternary electrocatalyst. The addition of Ir also enhances the durability of the catalyst. The enhancement in activity and durability is discussion based on CO stripping measurements and X-ray photoelectron spectroscopy analysis of the catalysts. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3060111] All rights reserved.