title: Preparation of carbon-supported core-shell Au-Pt nanoparticles for methanol oxidation reaction: The promotional effect of the Au core.
abstract: Core-shell Au-Pt nanoparticles with intimate contact of Pt and Au were prepared by a displacement reaction without formation of monometallic Au nanoparticles. The Au-Pt nanoparticles were dispersed on carbon (Au@Pt/C) and were used to catalyze methanol electrooxidation in acidic solutions at room temperature. The core-shell nanostructure was confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy, and specific catalytic activities were evaluated by CO anodic stripping voltammetry in 0.5 M H(2)SO(4) and by cyclic voltammetry in 1 M CH(3)OH + 0.5 M H(2)SO(4). The Au@Pt/C catalyst demonstrated enhanced specific activity in methanol electrooxidation and showed multiple CO stripping peaks which were all negatively shifted with respect to a similarly prepared Ag@Pt/C catalyst. The activity enhancement is attributed to the presence of Au underneath a very thin Pt shell where electron exchange between Au and Pt had promoted the formation of active oxygen species on Pt, which facilitated the removal of inhibiting CO-like reaction intermediates.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260.
authors.forename: Jianhuang
authors.initials: J
authors.lastname: Zeng
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Jim Yang
authors.initials: JY
authors.lastname: Lee
authors.forename: Weijiang
authors.initials: W
authors.lastname: Zhou