Regensburg 2025 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 32: Heterogeneous Catalysis I

O 32.1: Vortrag

Dienstag, 18. März 2025, 10:30–10:45, H25

Stability and reactivity of metal clusters on rutile TiO₂(110) under near-ambient pressure conditions — •Marina Isabel de la Higuera Domingo, Florian Kraushofer, Matthias Krinninger, Friedrich Esch, and Barbara A. J. Lechner — Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, 85748 Garching, Germany

Clusters are widely recognized for their unique performance in heterogeneous catalysis as they exhibit discrete electronic states that lead to strongly size-dependent catalytic properties [1]. However, their application in industrial processes is often limited by their instability under reaction conditions. At elevated temperatures, clusters tend to sinter, which reduces their surface area and alters their catalytic behavior.

Reducible oxides, such as titania (TiO₂), are effective supports to stabilize clusters and tune their activity through encapsulation induced by the strong metal-support interaction (SMSI) [2]. While metal nanoparticles on TiO₂ are well-studied, much less is known about the dynamics of clusters, in particular at high temperatures and pressures. In the present work, we employ near-ambient pressure scanning tunneling microscopy (NAP-STM) to study the effect of reducing and oxidizing atmospheres on metal clusters on rutile TiO₂(110). We will also delve into the influence of the sample stoichiometry on its reactivity at different ambient conditions [3].

[1] A.Beck, et al. Nat.Commun. 2020, 3220.

[2] S.J. Tauster. Acc. Chem. Res. 1987, 389-394

[3] F. Kraushofer, et al. Nanoscale 2024, 17825-17837

Keywords: NAP-STM; SMSI; clusters; titania; heterogeneous catalysis