Preparation and electrocatalytic oxidation performance of Pt/MnO₂-graphene oxide nanocomposites

A simple and eco-friendly approach was developed to prepare manganese dioxide functionalized reduced graphene oxide supported Pt nanocomposites (Pt/MnO₂-RGO) via chemical reduction process. The morphology and structure of as-prepared catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and X-ray diffraction (XRD). Subsequently, electrochemical properties of catalysts were systematically investigated by cyclic voltammetry (CV). As a result, the ultrafine Pt nanoparticles with an average diameter of 2.9nm were uniformly dispersed on the MnO₂-RGO surface. The Pt/MnO₂-RGO catalysts exhibited the superior electrochemical active surface area (79.4m²g^-1) and specific peak current density for methanol oxidation (24.7mAcm^-2), compared to Pt/reduced graphene oxide (Pt/RGO) and Pt/carbon black (Pt/CB). The improved electrocatalytic activity was mainly attributed to the better dispersion of Pt nanoparticles as well as the synergistic effect of the modified supports.