Decoration of ultrafine platinum-ruthenium particles on functionalized graphene sheets in supercritical fluid and their electrocatalytic property
作者：Jian Zhao Hao Xue Lin Zhang Jinhai Yu Haiqing Hu
關鍵字：Graphene，Platinum，Ruthenium，Electrocatalyst，Methanol oxidation
論文來源：期刊
發表時間：2012年
We report a simple and effective supercritical fluid route to uniformly load ultrafine metal
nanoparticles on the hydrophobic surfaces of graphene sheets. In the presence of supercritical carbon dioxide,PtRu alloy nanoparticles are decorated evenly on functionalized graphene sheets (FGSs) upon the reduction of organic platinum (II) and ruthenium (III) precursors, and its application as an electrocatalyst for methanol oxidation is studied. Transmission electron microscopy observation shows that highly dispersed PtRu metallic nanoparticles with an average size of about 3.11 nm are uniformly and densely distributed on the hydrophobic surface of FGSs. X-ray diffraction patterns demonstrate that the particles had a face-centered cubic crystal structure, and X-ray
photoelectron spectroscopy analysis indicates the existence of zero-valence metals. Compared with the widely used Vulcan XC-72 carbon black, the PtRu/FGS composites exhibit superior catalytic activity and stability for methanol oxidation. The huge surface area of graphene and uniform distribution of nanosized metal particles are two critical factors for the significantly enhanced electrocatalytic efficiency. The findings suggest that the supercritical fluid method is highly efficient in preparing graphene-supported metallic catalysts, and FGSs serve as a favorable electrocatalytic carrier for direct methanol fuel cells.