Single-step synthesis of PtRu/N-doped graphene for methanol electrocatalytic oxidation

In this work, a single-step route was applied to achieve the reduction of graphene oxide, functional doping of graphene with nitrogen, and deposition of well-dispersed PtRu alloy nanoparticles on the doped graphene simultaneously in the solvent mixture of ethylene glycol and N-methyl-2-pyrrolidone. Transmission electron microscopy, X-ray powder diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy were used to characterize the morphology and microstructure, while cyclic voltammetry, chronoamperometry and electrochemical impedance techniques were carried out to evaluate the electrocatalytic methanol oxidation activity and durability of the obtained PtRu/nitrogen-doped graphene catalysts. Compared to undoped PtRu/graphene, the nitrogen-doped PtRu/graphene catalyst presented better particle size distribution and improved activity and durability of methanol electrocatalytic oxidation, which could be further improved by optimization of the reaction time, temperature, as well as the composition of the reaction medium. The convenient single-step synthesis process for the PtRu/nitrogen-doped graphene catalysts is promising for the potential application of direct methanol fuel cells. (C) 2013 Elsevier Ltd. All rights reserved.