Kittel, M., Hoeft, J.T., Bao, S., Polcik, M., Toomes, R.L., Kang, J.H., Woodruff, D.P., Pascal, M. and Lamont, C.L.A. (2002) The local adsorption geometry of CO and NH3 on NiO(1 0 0) determined by scanned-energy mode photoelectron diffraction. Surface Science, 499 (1). pp. 1-14. ISSN 0039-6028Metadata only available from this repository.
The local adsorption structures of CO and NH3 on NiO(1 0 0) have been determined by C 1s and N 1s scanned-energy mode photoelectron diffraction. CO adsorbs atop Ni surface atoms through the C atom in an essentially perpendicular geometry (tilt angle 12±12°) with a C–Ni nearest-neighbour distance of 2.07±0.02 Å. NH3 also adsorbs atop Ni surface atoms with a N–Ni distance of 2.06±0.02 Å. These bondlengths are only very slightly longer than the comparable values for adsorption on metallic Ni surfaces. By contrast theoretical values obtained from total energy calculations, which exist for CO adsorption on NiO(1 0 0) (2.46 Å and 2.86 Å) are very much longer than the experimental value. Similar discrepancies exist for the N–Ni nearest-neighbour bondlength for NO adsorbed on NiO(1 0 0). Combined with the published measurements of the desorption energies, which also exceed the calculated bonding energies, these results indicate a significant failure of current theoretical treatments to provide an effective description of molecular adsorbate bonding on NiO(1 0 0).
|Uncontrolled Keywords:||Photoelectron diffraction; Chemisorption; Surface structure, morphology, roughness, and topography; Nickel oxides; Carbon monoxide; Ammonia; Single crystal epitaxy|
|Subjects:||T Technology > TP Chemical technology|
|Schools:||School of Applied Sciences|
|Depositing User:||Catherine Parker|
|Date Deposited:||06 Nov 2008 13:50|
|Last Modified:||10 Sep 2010 09:58|
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