Preparation of highly dispersed CuPt nanoparticles on ionic-liquid-assisted graphene sheets for direct methanol fuel cell

In this work, CuPt nanocomposites were decorated on ionic-liquid-assisted graphene and their electrocatalytic activities for methanol oxidation were investigated. The procedure involved the synthesis of graphene by electro-oxidation of pure graphite in an ionic-liquid/water solution, followed by the deposition of Cu nanoparticles on graphene and their further reduction of chloroplatinic acid. The catalysts were characterized by using transmission electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, Raman spectroscopy and X-ray diffraction. Subsequently, electrocatalytic activities of this catalyst for methanol oxidation were measured by cyclic voltammetry, chronoamperometry and CO-stripping voltammetry. Results showed that the electrocatalytic activity and stability of CuPt/ionic-liquid-assisted graphene for methanol oxidation was better than that on commercial carbon blacks, which was attributed to the increase of the graphene conductivity by ionic liquid and the facile removal of intermediate poisoning species with the aid of Cu, demonstrating that ionic-liquid-assisted graphene can be an alternative support for Pt immobilization in direct methanol fuel cells. (C) 2012 Elsevier B.V. All rights reserved.