Abstract
Electronic structure calcns. were performed on the chemisorption of at. oxygen on Ag(110) and on the subsequent reaction of this chemisorbed oxygen with ethylene. These calcns. show that the presence of subsurface oxygen (i) reduces the bond energy between silver and adsorbed oxygen and (ii) converts the repulsive interaction between adsorbed oxygen and (gas-phase) ethylene into an attractive one, thus making possible the epoxidn. reaction. The presence of subsurface oxygen diminishes an important four-electron destabilizing interaction (Pauli repulsion) between the occupied ethylene p orbital and a surface oxygen lone-pair orbital by shifting the band of ethylene p-oxygen lone-pair antibonding orbitals largely above the Fermi level. As for total combustion of ethylene, no C-H bond activation is found for several different geometries in which ethylene approaches the adsorbed oxygen atom
Original language | English |
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Pages (from-to) | 6469-6475 |
Number of pages | 6 |
Journal | Journal of Physical Chemistry |
Volume | 93 |
Issue number | 17 |
DOIs | |
Publication status | Published - 1989 |