Synthesis of surface-functionalized graphene nanosheets with high Pt-loadings and their applications to methanol electrooxidation

Surface-functionalized graphene nanosheets (GNSs) were synthesized from natural graphite via chemical oxidation and subsequent thermal exfoliation. High Pt metal loadings, up to 80 wt.%, were deposited over the synthesized GNS supports and the Pt particle size was maintained at less than 3 nm. The current densities of methanol electrooxidation with these Pt/GNS catalysts were at least twice as large as those observed with conventional Pt/C catalysts. Furthermore, these Pt/GNS catalysts maintained high Pt mass activities with increased Pt loading on the working electrode, ranging from 0.2 to 2.0 mg/cm(2). This improved mass activity indicates that our electrocatalysts are able to provide more efficient Pt utilization for alcohol electrooxidation compared to conventional catalysts. (C) 2010 Elsevier Ltd. All rights reserved.