Probing the Coverage Dependence of Site and Adsorbate Configurational Correlations on (111) Surfaces of Late Transition Metals

Abstract

Correlations between adsorption energies allow for the prediction of a large set of adsorption energies from a few quantum-chemical calculations, enabling quick evaluations of the catalytic activity of surfaces for multistep reactions. A critical question is whether these correlationsinitially established at low coverage on geometrically similar surfacesare useful at high coverage and in various geometric environments, which are the relevant industrial conditions of real catalysts. To answer this question, we use density functional theory to calculate almost 900 adsorption energies of several atomic adsorbates on late transition metal fcc (111) surfaces at a variety of coverages and configurations. We observe strict requirements of the geometric similarity between adsorption sites for the existence of correlations in adsorption energies. We also find that the introduction of higher coverages generally weakens and changes the correlations. We use our results to assess a simple model constructed from previously discovered scaling relationships and discuss their ramifications on catalyst discovery as well as strategies to incorporate this coverage dependence