Regensburg 2022 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 3: Focus Session: Single Atom Catalysis 1

O 3.7: Vortrag

Montag, 5. September 2022, 12:15–12:30, H4

Adsorption sites and thermal stability of Pt adatoms on Fe₂O₃(1102) — •Ali Rafsanjani Abbasi, Florian Kraushofer, Lena Haager, Moritz Eder, Jiri Pavelec, Giada Franceschi, Michele Riva, Michael Schmid, Ulrike Diebold, and Gareth S. Parkinson — Institute of Applied Physics, TU Wien, Austria

Oxide-supported Pt catalysts offer superior performance because of their high activity and/or selectivity for many important chemical reactions. However, the high cost of Pt and its susceptibility to CO poisoning are two drawbacks to its role as a catalyst. Downsizing catalyst clusters to single atoms is an effective way to reach maximum efficiency, and so-called “single-atom catalysis” is now an important field of research [1]. Nevertheless, stabilizing single Pt atoms on oxide supports without compromising catalytic activity is still a key challenge. Here, we present a surface science study to investigate the local binding environment of Pt adatoms deposited on Fe₂O₃(1102)−(1×1) under UHV conditions. Extensive STM and XPS studies at different Pt surface coverages on Fe₂O₃(1102) revealed that Pt single atoms are highly stable at room temperature. STM images showed that Pt single atoms are adsorbing at two distinct sites with different apparent heights. Through an atom-by-atom analysis, the relative contributions of two types of Pt adsorption sites were determined for different surface coverages. Moreover, thermally induced sintering of the Pt single atoms is traced by means of XPS and STM.

[1] G. S. Parkinson, Catal. Lett. 149, 1137 (2019).