A carbon supported hollow Pt nanosphere electrocatalyst was prepared at room temperature in a homogeneous solution employing cobalt metal nanoparticles as sacrificial templates. TEM measurements showed that carbon supported Pt nanospheres were coreless and composed of discrete Pt nanoparticles with the crystallite size of about 2.2 +/- 0.2 nm. XRD results showed that the hollow Pt nanospheres had a face-centered cubic structure. Electrochemical measurements demonstrated that the carbon supported hollow Pt nanosphere electrocatalyst exhibited enhanced electrocatalytic performance for methanol oxidation compared with carbon supported solid Pt nanoparticles. (c) 2006 Elsevier B.V. All rights reserved.