Dresden 2026 – scientific programme
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O: Fachverband Oberflächenphysik
O 23: Catalysis and surface reactions – Poster
O 23.9: Poster
Monday, March 9, 2026, 18:00–20:00, P2
Size selected Pt clusters on a CeO2(111) support: mobility, reactivity and dimensionality — •Fabian Heisinger, Johanna Reich, Mina Soltanmohammadi, Rasmus Bischoff, Friedrich Esch, and Barbara A.J. Lechner — TU Munich, Germany
Ceria is a renowned material for its exceptional oxygen storage capacity with applications in catalysis. Central to this functionality are oxygen vacancies and their mobility. In interaction with metal catalyst particles, this reducible oxide is highly versatile, as we demonstrate for size-selected Pt clusters on a single-crystalline ceria film. We study oxidation reactions as a function of cluster size, dimensionality, support reduction, and gas environment. With conventional and fast STM, we directly observe the dynamics of surface vacancies and supported clusters to determine cluster shape changes related to defect density and sintering. We combine this cluster height and coverage monitoring with LEED and XPS to characterize the CeO2 films in crystallinity, thickness, oxidation state, and Pt coverage. We demonstrate that the Pt cluster dimensionality during sintering can be steered by controlling the oxygen vacancy coverage on the support[1]. Through STM, we track the mobility of O vacancies in an effort to correlate their dynamics with cluster properties, and the cluster dynamics to unravel the influence of their shape on stability and catalytic activity. These dimensionality-tuned, size-selected clusters provide an ideal platform to study the structural dynamics of small metal clusters during an ongoing oxidation reaction.
[1] Reich, Johanna, et al. ACS catalysis 15 (2025): 18369-18382.
Keywords: STM; Ceria; Platinum; Cluster