摘要： With infrared reflection absorption spectra and temperature-programmed desorption of CO as a probe molecule, we investigated the surface structure of Au–Pt bimetallic nanoclusters on thin-film Al2O3/NiAl(100) under ultrahigh vacuum conditions. Vapor Au and Pt (0.0–2.0ML) were sequentially deposited onto Al2O3/NiAl(100) at 300K to form bimetallic clusters; under the kinetic constraint, the order of the metal deposition made a variation in the surface structure of the grown clusters. For the deposition of Au onto Pt clusters (first Pt and then Au), the deposited Au decorated preferentially and then aggregated the edge sites of Pt clusters, instead of decorating the rest of Pt surface. For the metal deposition in the reverse order, the deposited Pt covered uniformly the surface of existing Au clusters and no preferential adsorption site was indicated. The infrared absorption for CO on Au sites was significantly enhanced when alloying occurred; this enhancement is primarily a local field effect depending on the coordination of CO-binding Au, and hence provides additional structural characterization of the grown clusters. •Au-Pt bimetallic clusters grown on Al2O3/NiAl(100) at 300K contrast structurally the favored one.•The structural features due to the order of metal deposition differ from other comparable systems.•The enhanced infrared absorption for CO on Au sites complements the structural characterization. 出版者： Kidlington: Elsevier B.V 出版日期： 2013-12-01 出處： Surface science, 2013-12, Vol.618, p.132-139 版權： 2013 Elsevier B.V. 版權： 2014 INIST-CNRS 識別號： ISSN: 0039-6028 識別號： EISSN: 1879-2758 識別號： DOI: 10.1016/j.susc.2013.09.013 識別號： CODEN: SUSCAS
