Regensburg 2022 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 69: Surface Reactions and Heterogeneous Catalysis 2

O 69.3: Vortrag

Donnerstag, 8. September 2022, 15:45–16:00, H4

CO oxidation on small size-selected Pt clusters supported on Fe3O4(001) — •Johanna Plansky¹, Sebastian Kaiser¹, Farahnaz Maleki², Ke Zhang³, Wolfgang Harbich⁴, Ueli Heiz¹, Sergio Tosoni², Barbara A.J. Lechner¹, Gianfranco Pacchioni², and Friedrich Esch¹ — ¹Technical University of Munich, Garching, Germany — ²University of Milano-Bicocca, Milano, Italy — ³Technical University of Denmark, Kgs. Lyngby, Denmark — ⁴École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland

Oxide-supported metal nanoparticles and clusters are common catalysts for heterogeneous reactions such as exhaust gas treatment. By studying supported size-selected clusters, we disentangle the influence of cluster size and support on reaction mechanisms. In the Ptn/Fe3O4(001) model system, we observe a complicated interplay between lattice oxygen reverse spillover, cluster encapsulation and gas phase pressure dependence. Sophisticated pulsed-valve reactor experiments (Sniffer-MS) combined with variable temperature scanning tunneling microscopy (STM) reveal the reaction of CO with lattice oxygen occurs on the cluster and not at the interface, but it is rapidly quenched by the strong metal-support interaction (SMSI). We will further demonstrate how UHV-based experiments can be quantified to provide turnover frequencies (TOFs) for comparison with real catalysts.