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Platinum nanoparticles have been deposited on monodispersed hard carbon spherules (Pt/HCS) by reduction of H2PtCl6 with Na2S2O4 in aqueous solution or by reduction of K2PtCl6 directly with ethylene glycol. For comparison, Pt nanoparticles have also deposited on mesocarbon microbeads (Pt/MCMB) by above second method. SEM image shows that the size of highly dispersed Pt nanoparticles on HCS by reduction with ethylene glycol is 4-5 nm, consistent with estimation from XRD pattern. Structural analysis by HRTEM reveals that most of the Pt nanoparticles on HCS have faceted crystalline structures. The deposition of Pt nanoparticles is found to be very sensitive to the water content in ethylene glycol. Electrochemical analysis shows that the Pt/HCS catalyst exhibits higher catalytic activity for electrooxidation of methanol than that of Pt/MCMB catalyst and commercial Pt/Vulcan XC-72 catalyst.