Regensburg 2022 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 10: Focus Session: Single Atom Catalysis 2
O 10.5: Vortrag
Montag, 5. September 2022, 16:30–16:45, H4
Rh and Ir single atoms on Fe3O4(001): local structure affecting catalytic properties — •Matthias Meier1,2, Zdenek Jakub1, Jiri Pavelec1, Michael Schmid1, Ulrike Diebold1, Cesare Franchini2,3, and Gareth S. Parkinson1 — 1Institute of Applied Physics, Technische Universität Wien, Vienna, Austria — 2Faculty of Physics and Center for Computational Materials Science, University of Vienna, Vienna, Austria — 3Department of Physics and Astronomy, Alma Mater Studiorum, Università di Bologna, Bologna, Italy
Single-atom catalysts are often supported by cheap oxides, such as iron oxides. As a model system [1], magnetite (Fe3O4), specifically its (001) facet has been used because it offers stable sites for single-atom adsorption up to high temperatures. Here, I will demonstrate how important the support is for the stability of single-atoms, as well as their catalytic properties. Rh and Ir [2] single atoms utilize Fe vacancies in the subsurface of the reconstructed Fe3O4(001) unit cell to incorporate into the surface layer. Changing the positions of Fe atoms in the support as part of the incorporation process enables the single atoms to be accommodated in a more favorable configuration than if they were adsorbing on top of the surface. Their catalytic properties are drastically affected by changes in the atomic environment. Incorporation temperatures vary depending on both coverage and the presence or absence of adsorbates, such as CO.
[1] R. Bliem et al., Science 346, 1215 (2014). [2] Z. Jakub et al., Angew. Chemie Int. Ed. 58, 13961 (2019).