Berlin 2024 – scientific programme
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O: Fachverband Oberflächenphysik
O 50: Supported Nanoclusters: Structure, Reaction, Catalysis
O 50.6: Talk
Wednesday, March 20, 2024, 11:45–12:00, TC 006
Bimetallic Pd-Rh core-shell nanoparticles supported on Co3O4(111): atomic ordering and stability — •Yaroslava Lykhach1, Alexander Simanenko1, Lukáš Fusek1,2, Tomáš Skála2, Nataliya Tsud2, Sascha Mehl3, Olaf Brummel1, and Jörg Libuda1 — 1Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany — 2Charles University, Prague, Czech Republic — 3Elettra-Sincrotrone Trieste SCpA, Basovizza-Trieste, Italy
The activity of bimetallic Pd-Rh catalysts can be efficiently tuned by geometric and electronic effects resulting from the atomic arrangement and bimetallic interactions between the Pd and Rh atoms. Additional functionalities arising from the electronic metal-support interaction (EMSI) can be introduced by the use of reducible oxide supports. We investigated the impact of the EMSI on the atomic ordering and stability of bimetallic Pd@Rh and Rh@Pd core@shell nanostructures supported on well-ordered Co3O4(111) films by means of synchrotron radiation photoelectron spectroscopy (SRPES). Depth profile analysis of the charge transfer and the oxidation states of Rh and Pd was performed using tunable synchrotron light during the preparation and annealing of the model systems in UHV. We found that the EMSI yields a fraction of Rh3+ species at the interface between metallic Rh nanoparticles and Co3O4(111). Annealing the model systems triggers atomic rearrangement in the core@shell nanostructures, leading to the formation of thermodynamically favorable Pd-rich shells and Rh-rich cores in both core@shell systems.
Keywords: bimetallic nanoparticles; reducible oxide; electronic metal support interaction; atomic ordering; supported nanoparticles