AVS 52nd International Symposium
    Surface Science Monday Sessions
       Session SS1-MoA

Paper SS1-MoA5
The Electronic Structure Effect in Heterogenous Catalysis

Monday, October 31, 2005, 3:20 pm, Room 202

Session: Catalysis for the Hydrogen Economy
Presenter: A. Nilsson, Stanford University
Authors: A. Nilsson, Stanford University
L.G.M. Pettersson, Stockholm University, Sweden
B. Hammer, University of Arhus, Denmark
T. Bligaard, Technical University of Denmark
C.H. Christensen, Technical University of Denmark
J. Norskov, Technical University of Denmark
Correspondent: Click to Email
Transition metals are used extensively as catalysts and the variation in the catalytic activity for a given reaction is determined largely by the differences in the strength of the adsorbate-surface interaction from one metal to the next. In the following presentation we will demonstrate how we can understand trends in adsorbate-surface interactions based on a particularly simple picture that was originally developed to describe the difference in reactivity for hydrogen dissociation on metal surfaces, the d-band center model.@footnote 1@ We will show that it applies quite generally and in particular we will show that it can be validated through an experimental determination of the electronic structure of both occupied and unoccupied adsorbate states in an atom specific way using x-ray emission spectroscopy (XES) and x-ray absorption spectroscopy (XAS) together with density functional theory calculations (DFT).@footnote 2@ It has been shown that the catalytic activity of different transition metals as catalysts for ammonia synthesis is given by the strength of the nitrogen-surface bond.@footnote 3@ We will show that XES, XAS and DFT studies of atomic nitrogen can probe details of the metal d induced adsorbate electronic structure that can be linked to the chemisorption bond strength. @FootnoteText@ @footnote 1@B. Hammer and J. K. Norskov, Nature 376, 238 (1995). @footnote 2@A. Nilsson and L. G. M. Pettersson, Surf. Sci. Reps. 55, 49 (2004). @footnote 3@A. Logadottir, T. H. Rod, J. K. Norskov, B. Hammer, S. Dahl and C. J. H. Jacobsen, J. Catal. 224, 206 (2001).