An easy approach for the synthesis of platinum nanoparticles supported on reduced graphene oxide (RGO) was investigated. Pt/RGO-II and Pt/RGO-IV hybrids were prepared using sodium borohydride as the reductant to synchronously reduce graphene oxide (GO) and Na2PtCl4 or H2PtCl6, respectively. The whole synthetic procedure was easily carried out in one pot at room temperature. The Pt/RGO-II and Pt/RGO-IV hybrids were characterized by X-ray diffraction, Raman spectrometry, transmission electron microscopy and X-ray photoelectron spectroscopy. Their electrochemically catalytic activity for direct methanol oxidation was evaluated. Both the Pt/RGO-II and Pt/RGO-IV hybrids show good catalytic activity. However, the Pt/RGO-II hybrids exhibited better electrocatalytic activity and stability for the oxidation of methanol and ethanol than the Pt/RGO-IV hybrids, which may as the PtCl42- has high reduction potential so that it is easy to be reduced. These hybrids show great potential application for use in fuel cells. (C) 2013 Elsevier Ltd. All rights reserved.