▎ 摘　　要

Ultrafine Pt nanoparticles with an average diameter of only 1.7 nm are uniformly dispersed onto MnO2-functionalized graphene sheets by a facile and cost-effective method. In such a ternary Pt/MnO2/graphene sheets (Pt/MnO2/GS) nanohybrid, each component provides unique and critical function to achieve optimized utilization of metallic platinum, allowing it to express ultrahigh electrocatalytic activity ability in methanol oxidation (the forward anodic peak current density is up to 1224 mA mg(-1)) in comparison with Pt/graphene sheets (Pt/GS), Pt/Vulcan XC-72 (Pt/XC-72) and Pt/MnO2/XC-72 catalysts. This work could provide new insights into the fabrication of the next generation high-performance electrocatalyst and promote their practical application in fuel-cell technologies. (C) 2013 Elsevier B.V. All rights reserved.