Towards a better understanding of activity and selectivity trends involving K and O adsorption on selected metal surfaces

Abstract

Oxidation reactions are the basis of many applications in chemical industry, and the reaction rates are increased by the presence of a suitable metallic surface that acts as a catalyst. The basic factor in explaining the reaction dynamics is the electronic structure of the catalyst and the reactants, which can be determined by modern computational methods. Typically, catalytic reactions on metal surfaces involve steps such as adsorption, dissociation, and diffusion. Understanding the elementary steps contributes to the overall understanding of catalytic properties of metal surfaces.

This study presents first-principles calculations of elementary processes on silver (110) and lead (100) surfaces. The preferred oxygen adsorption sites and the dissociation of the oxygen molecule on Ag(110) are clarified, and the diffusion and vibration of oxygen are analyzed.

On Pb(100) surface, potassium is shown to prefer substitutional adsorption sites and form an ordered structure at 0.5 monolayers coverage. Finally, the oxidation of Pb(100) surface results in a two layer oxide structure where oxygen occupies distorted hollow sites on and below the top surface layer.