Graphene is considered as a promising catalyst support for polymer electrolyte membrane (PEM) fuel cells because of its excellent properties. Recent studies showed that electrocatalytic activity, fuel cell performance, catalyst utilization efficiency and long term durability can be improved by using graphene as the catalyst support. In here, we report the synthesis of graphene nanoplatelets (GNPs) supported platinum catalysts using supercritical carbon dioxide (scCO(2)) deposition technique. The prepared catalysts were characterized in terms of their structure, morphology and thermal behavior by using X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The electrocatalytic and half-cell performances of the as-prepared catalysts were investigated by cyclic voltammetry (CV) and PEM fuel cell performance testing. Small size and well distribution of Pt nanoparticles on GNPs surfaces were achieved by using scCO(2) deposition which improves the PEM fuel cell performance. To the best of our knowledge decoration of Pt nanoparticles on GNPs via scCO(2) deposition and their detailed fuel cell performances were presented for the first time in the literature. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.