A simple route is described for the synthesis of well-dispersed and highly alloying PtCo bifunctional nanoparticles supported on ordered mesoporous carbons (Pt100-xCox/OMC) by the simultaneous pyrolysis of carbon and metal precursors in a mesoporous silica as the hard template. A variety of different spectroscopic and analytical techniques was used to thoroughly characterize the Pt100-xCox/OMC samples. By X-ray diffraction, N-2 adsorption/desorption isotherms and transmission electron microscopy, it was found that Pt100-xCox/OMC possessed well-dispersed Pt/PtCo nanoparticles (2-3 nm) supported on high surface area (similar to 1000 m(2) g(-1)) and regular pore channels (similar to 2.8 nm). Among Pt100-xCox/OMC catalysts, the Pt50Co50/OMC was found to have superior electrocatalytic activity and the tolerance to methanol crossover during oxygen reduction reaction as compared to typical commercial electrocatalysts. This may be attributed to the dispersion and unique nanostructure of highly alloyed PtCo nanoparticles supported on Pt50Co50/OMC evidenced by X-ray absorption spectroscopy. (C) 2011 Elsevier B.V. All rights reserved.