Dresden 2017 – wissenschaftliches Programm
MM 14: Topical session: Interface-Controlled Microstructures: Mechanical Properties and Mechano-Chemical Coupling - Electro- and mechno-chemical coupling
MM 14.4: Vortrag
Montag, 20. März 2017, 16:30–16:45, BAR 205
Oxygen adsorption on strained transition metal surfaces: An ab initio study of mechano-chemical coupling — •Gregor Feldbauer, Anja Michl, and Stefan Müller — Hamburg University of Technology, Institute of Advanced Ceramics, Germany
Mechanical deformation can affect the adsorption and reaction processes of reactants on surfaces. Thus, by straining catalytically active surfaces their reactivity as well as selectivity can be influenced, which is of high importance, for example, in the field of heterogeneous catalysis. Here, transition metal surfaces, like Pd(111) and Ir(111), interacting with atomic oxygen are used as model systems. At first, the adsorption characteristics, e.g. the energetics, are investigated within the framework of density functional theory (DFT). The most favourable adsorption configurations are identified via the cluster expansion approach using DFT input data. Secondly, for various favourable oxygen configurations at the transition metal surfaces biaxial strain is applied in the surface plane to obtain the response of the adsorption energetics. Particularly, the coupling parameter between strain and adsorption energies is of interest to allow for a comparison with experiments. The coupling parameter is affected by the oxygen coverage as well as the occurrence of oxygen incorporation.