Reflection-absorption infrared spectroscopy (RAIRS) and near-edge x-ray absorption fine structure (NEXAFS) have been used, with isotopic 14NO/15NO mixtures, to determine the structure and orientation of the monolayer species formed by NO adsorption on Ag{111} at 40 to 60 K. The adlayer is composed of NO dimers bonded with the N–N axis in the surface plane and with the molecular plane tilted away from the surface normal by about 30°. This structure provides a simple basis for understanding the facile reaction to adsorbed N2O and O which occurs on heating to 70 to 90 K.

CO dissociation: Three most probable pathways to CO dissociation on the Fe (100) surface exist: a) direct, CO→C+O (-) and H-assisted b) H+CO↔HCO→CH+O (-) or c) CO+H↔COH→C+OH (-). Under high hydrogen pressure conditions and highly occupied surfaces the formation of HCO and subsequent dissociation to CH+O may at best compete with direct dissociation.

A first principles calculation of the vibrational modes of Pb(111) thin films of thickness up to 14 layers reveals the existence of localized vibrational modes at the slab's surface. Both longitudinal and transverse surface modes localized a few atomic layers are found at energies above the bulk bands. The frequency of these modes presents a bilayer oscillatory behavior. The electron-phonon interaction of the slab's quantum well states is also calculated. We find a large (small) deformation potential for the lowest unoccupied (highest occupied) quantum well state. Its absolute value is also oscillatory with the number of layers.

No abstract

No abstract