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MM: Fachverband Metall- und Materialphysik
MM 21: Interface Controlled Properties, Nanomaterials and Microstructure Design
MM 21.3: Vortrag
Mittwoch, 19. März 2025, 16:15–16:30, H22
Unravelling the metal-support interaction of sub-monolayer Pt thin films on manganese oxide via photoelectron spectroscopy — •Manuela Arztmann1, Raul Garcia-Diez1, Johannes Frisch1, and Marcus Bär1,2,3,4 — 1Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Germany — 2Energy Materials In-Situ Laboratory Berlin, Germany — 3Helmholtz-Institut Erlangen-Nürnberg für Erneuerbare Energien, Germany — 4Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
In heterogeneous catalysis, metal-support interactions (MSI) have been shown to greatly influence the selectivity and activity of catalysts, with reducible supports as preeminent examples. The various oxidation states accessible for manganese oxide allow to accommodate different amounts of oxygen vacancies, making it a promising support with tunable properties for catalysis. Studies show that the oxidation state of manganese is closely linked to its promoter capabilities in catalysis, though the MSI is not well understood so far. In this 'in-system' study, the chemical and electronic structure of the interface between Pt and manganese oxide was investigated by XPS/UPS as a function of Pt surface coverage. The thin film model catalysts were prepared by e-beam evaporation in a system directly connected to the XPS/UPS setup, enabling precise control of the Pt thickness from sub-monolayer levels to thick metal-like Pt layers, allowing for a systematic study of the property evolution in the near surface region without leaving vacuum conditions. Our results reveal an enhanced reduction of the manganese oxide with increasing Pt surface coverage indicating significant MSI.
Keywords: metal-support interaction; XPS; UPS; manganese oxide