AVS 47th International Symposium
    Surface Science Wednesday Sessions
       Session SS1-WeM

Invited Paper SS1-WeM3
Chemical and Electronic Properties of Ni/Pt(111) Bimetallic Surfaces: Unique Surface Reactivity at the Monolayer Ni Coverage

Wednesday, October 4, 2000, 9:00 am, Room 208

Session: Chemical Interactions and Surface Reactivity
Presenter: J.G. Chen, University of Delaware
Authors: J.G. Chen, University of Delaware
J. Eng, Jr., University of Delaware
M.T. Buelow, University of Delaware
H.H. Hwu, University of Delaware
N.A. Khan, University of Delaware
Correspondent: Click to Email
In a recent paper we reported the observation of an "anomalous" reactivity of Ni/Pt(111) bimetallic surfaces at Ni coverages around one monolayer (ML) [3]. For example, after a saturation exposure of D2 to a Ni/Pt(111) surface with one ML Ni, the desorption of D2 occurs at 220 K from the TPD measurements. This desorption temperature is lower than that of D2 desorption from either Pt(111) (294 K) or Ni(111) (379 K). The lower desorption temperature suggests that the D atoms are rather mobile on the one ML Ni/Pt(111) surface. We have tested this idea by investigating the hydrogenation of cyclohexene to cyclohexane, and the hydrodesulfurization of thiophene to 1,3-butadiene on the one ML Ni/Pt(111) surface. In both cases the hydrogenation reactions take place at around 220 K under UHV conditions; these two reactions do not occur on either Pt(111) or Ni(111) under similar experimental conditions. In this talk we will present these latest TPD results, as well as our characterization of the chemical and electronic properties of the Ni/Pt(111) surfaces using high-resolution electron energy loss spectroscopy (HREELS), near-edge X-ray absorption fine structure (NEXAFS), and X-ray photoelectron spectroscopy (XPS).