Ethylene hydrogenation on Pt thin films on Ni(1 0 0) surface

• Published in: Surface science Vol. 474; no. 1; pp. 14 - 20
• Main Authors: Egawa, Chikashi, Endo, Satoshi, Iwai, Hidekazu, Oki, Shoichi
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.03.2001; Amsterdam Elsevier Science; New York, NY
• Subjects: Adsorption and desorption kinetics; evaporation and condensation; Alkenes; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Hydrogen atom; Nickel; Physics; Platinum; Solid-fluid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thermal desorption; Hydrogen atom; Nickel; Thermal desorption; Alkenes; Platinum; Thin films; Adsorption; Ethylene; Thermodesorption; LEED; Experimental study; Hydrogenation; X-ray photoelectron spectra
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(00)00978-X

From XPS and LEED studies, a layer-by-layer growth of Pt thin films is indicated up to 8 ML coverage on Ni(1 0 0) surface while a (1×1) structure changes to a disordered structure above 2 ML of Pt film thickness. The 1 ML Pt overlayer, as a model (1 0 0) surface of Pt–Ni alloy single crystal, shows a considerable d-band narrowing probably due to the formation of an interface state with the Ni substrate. This induces weakly adsorbed hydrogen atoms and ethylene molecules and, as a result, the maximum evolution of ethane is observed around 200 K. A wide d-band extending to −6 eV binding energy is developed for Pt 6 ML film characteristic of bulk Pt electronic states, resulting in a similar surface chemistry of ethylene as on Pt(1 1 1) surface.