AVS 47th International Symposium
    Surface Science Thursday Sessions
       Session SS2+VT-ThM

Paper SS2+VT-ThM2
Adsorption of Hydrogen on Clean and Alkali-modified Low-index and Stepped Copper Surfaces

Thursday, October 5, 2000, 8:40 am, Room 209

Session: Adsorption and Desorption Phenomena II
Presenter: J. Onsgaard, Odense University/University of Southern Denmark
Authors: L. Thomsen, Odense University/University of Southern Denmark
J. Onsgaard, Odense University/University of Southern Denmark
P.J. Godowski, University of Wroclaw, Poland
S.V. Hoffmann, University of Aarhus, Denmark
L. Bech, Odense University/University of Southern Denmark
P. Moller, Odense University/University of Southern Denmark
Correspondent: Click to Email
The interest for adsorption of low molecular gases like H and CO@sub 2@ on alkali-modified copper surfaces stems from the promoting role of the alkali metals in heterogeneous catalysis. Due to the substantial lowering of the work function with the addition of the alkali metal, pronounced changes in the adsorption and reaction properties of the copper surfaces are observed. The adsorption of atomic hydrogen on clean and potassium-modified Cu(110), Cu(100) surfaces and the stepped Cu(115), Cu(117) and Cu(112) surfaces has been studied. Typically, two hydrogen-induced states in the valence band have been found on the clean crystal and assigned to one state receding in the subsurface and another state at the surface of the crystal. Two states due to hydrogen are also observed on the potassium-modified surfaces and assigned to a potassium-hydrogen bond and a copper-hydrogen bond. Coadsorption of H and CO@sub 2@ on the K/Cu surface results in formation of formate with high efficiency on the most corrugated surfaces.