Enhanced electrocatalytic performance of Pt-based nanoparticles on reduced graphene oxide for methanol oxidation

Pt-based materials have been widely used as electrocatalysts in direct methanol fuel cells (DMFCs) due to their significant activity for methanol oxidation and the superior poison tolerance. In this study, several Pt-based catalysts (PtSn. PtW, and PtMo) supported on reduced graphene oxide (RGO) are successfully synthesized in an ethylene glycol (EG)-water system for the first time. The microstructure and morphology of the synthesized materials are investigated by X-ray diffraction, Raman spectroscopy, and transmission electron microscopy. It is shown that highly dispersed PtM (M = Sn, W, and Mo) nanoparticles with a size of 2-3 nm are homogeneously deposited on the surface of RGO sheets. Their electrocatalytic performances in methanol oxidation are investigated by cyclic voltammetry and amperometric method. The RGO/PtM catalysts exhibit much higher catalytic activity and stability than the RGO/Pt nanocomposites. Among these RGO/PtM catalysts, RGO/PtSn nanocomposites show the best catalytic performance. It is proposed that the addition of a second element, which creates much more Pt active sites for methanol oxidation, is responsible for the improved catalytic performance. These results imply that the prepared RGO/PtM nanocomposites could be promising electrocatalysts for high-performance DMFCs applications. (C) 2012 Elsevier B.V. All rights reserved.