▎ 摘　　要

Herein, for the first time, bimetallic nanoparticles supported on graphene nanoplatelets (PtNi/GNPs, PtFe/GNPs, PtCu/GNPs) were prepared as sequentially through supercritical carbon dioxide (scCO(2)) technique. The physicochemical properties of the prepared catalysts were characterized by XRD, TEM, EDX, TGA, ICP-MS and Raman spectroscopy. Furthermore, the catalytic activity of bimetallic catalysts was tested using a three-cell cyclic voltammetry. PtNi/GNPs catalyst showed the best catalytic activity towards both hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR). Finally, to investigate the improvement of the cell performances, polarization curves were presented. It was found that the PtNi/GNPs catalyst exhibited highest performance (907.5 mA/cm(2), 0.54 mW/cm(2) @ 0.6 V) when the catalyst was used as anode electrode. We believe that this work will serve as a guide to the fuel cell research community in the selection of a promising route for the development of new low-cost and efficient electrocatalysts for PEMFC. (C) 2020 Elsevier B.V. All rights reserved.