SKM 2023 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 81: Oxide and Insulator Surfaces I: Adsorption and Reaction of Small Molecules
O 81.2: Vortrag
Donnerstag, 30. März 2023, 15:15–15:30, CHE 91
Predicting platinum adatom geometries on hematite for single-atom catalysis — •Florian Buchner, Ralf Wanzenböck, Jesús Carrete, and Georg K. H. Madsen — Institute of Materials Chemistry, TU Wien, 1060 Vienna, Austria
In single-atom catalysis, where isolated adatoms anchored on a support are used as catalysts, performance is highly sensitive to the charge state and coordination of the adatoms. This offers new avenues to design and tune catalysts. But to do so efficiently, a detailed understanding of the potential energy surface (PES) of the adatom-substrate system is needed.
In this theoretical study, we present an application of an evolutionary algorithm, the covariance matrix adaptation evolution strategy (CMA-ES) [M. Arrigoni et al., npj Comput Mater 7, 1–13 (2021)], to the prediction of Pt adatom configurations on the (1102) surface of hematite (α-Fe2O3).
We find a rich PES that is not only governed by the large-scale adatom geometry but also reflects competing electron localization between the Pt and substrate Fe atoms, giving rise to sets of geometrically almost identical structures whose energies nonetheless span an appreciable range. We further discuss the effect of substrate doping on this localization and argue that a combination of different experimental methods and theory is required to understand observed adatom geometries.