Oxygen adsorption on Ag(110): density functional theory band structure calculations and dynamical simulations

Abstract

The adsorption of oxygen on silver surfaces is one of the crucial steps in the catalytic partial oxidation of ethene. From experiment it is known that O 2 physisorbs at low temperatures ( T<40 K), whereas molecular and dissociative chemisorption is observed at higher temperatures. In this work, we present the results of a theoretical study based on quasi-classical trajectory simulations of the scattering of an O 2 beam incident at the Ag(110) surface. The interaction of O 2 with the Ag surface was described by means of a London–Eyring–Polanyi–Sato model potential, which accounts for the electronic charge transfer from the metal surface to the incoming O 2 molecule. This potential was built starting from the results of density functional theory band structure calculations obtained for the interaction of an oxygen atom with the high symmetry adsorption sites of the (110) surface. For the AgAg interactions, both a harmonic Lennard–Jones potential and a many-body tight-binding potential were used. The dependence of the molecular and dissociative adsorption probability on the O 2 translational and internal energies, on the incidence angles of the O 2 beam at the Ag surface, and the influence of the Ag surface temperature were investigated.