Berlin 2024 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 59: Oxide and Insulator Interfaces II
O 59.10: Vortrag
Mittwoch, 20. März 2024, 17:15–17:30, MA 144
Surface Structure of Vicinal Magnetite and the Adsorption of Formic Acid — •Marcus Creutzburg1, Heshmat Noei1, Vedran Vonk1, Wernfried Mayr-Schmölzer2, Gregor Vonbun-Feldbauer2, and Andreas Stierle1,3 — 1Centre for X-ray and Nano Science (CXNS), Deutsches Elektronen-Synchrotron DESY, Hamburg — 2Institut für Keramische Hochleistungswerstoffe, Technische Universität Hamburg — 3Fachbereich Physik, Universität Hamburg
The study of vicinal magnetite (Fe3O4) surfaces, with regularly ordered terraces and steps, and their interaction with carboxylic acids is one approach towards an atomic understanding of the oxide/organic interface in complex nanomaterials and active facets during catalytic reactions. In this contribution a (112)-oriented magnetite single crystal is studied using various experimental techniques complemented by DFT calculations. We can show using LEED and STM that this surface is stable after UHV preparation and presents (001)- and (111)-oriented nanosized terraces, confirmed by SXRD. Formic acid (HCOOH) is typically used as a probe molecule and as a representative for larger carboxylic acids. FT-IRRAS reveals that three different formate species are present on the surface after adsorption of formic acid: bidentate bridging on the (001) facets and chelating and quasi-bidentate on the (111) facets, similar to the respective planar surfaces [1,2]. Polarization-dependent FT-IRRAS reveals that the majority of formate is adsorbed across the step edges. [1] Arndt et al., Comm. Chem. 2(92) (2019) [2] Creutzburg et al., J. Phys. Chem. Lett. 12(15) (2021)