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O: Fachverband Oberflächenphysik

O 55: Oxide and insulator surfaces: Structure, epitaxy and growth II

O 55.6: Vortrag

Mittwoch, 11. März 2026, 12:00–12:15, HSZ/0204

Structural and electronic evolution of noble metal-deposited CeO2 catalysts: from model to powder systems — •Zairan Yu, Shuang Chen, Wangtao Li, Alexei Nefedov, Christof Wöll, and Yuemin Wang — Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany

The interaction between noble metals and oxide supports is crucial in heterogeneous catalysis, governing key reactions such as CO oxidation and the water-gas shift. Pt- and Pd-ceria systems show particularly strong electronic and structural metal-support interactions among these reactions. Despite extensive investigation, the atomic-scale structure and reactivity of these interfaces remain incompletely understood. Here, we combine polarization-resolved IRRAS on single-crystal surfaces and in situ UHV-FTIR transmission studies on ceria nanoparticles, using CO as a probe to elucidate surface structural dynamics and active sites. For Pt/CeO2(111), IRRAS and DFT results reveal that isolated Pt single atoms are not stabilized on the surface, but instead migrate into subsurface interstitial sites at low coverages, giving rise to a characteristic blue-shifted CO band at 2169 cm-1. In the Pd/CeO2/γ-Al2O3 system, highly dispersed Pd cations embedded in the ceria matrix with nearby interfacial oxygen vacancies are identified, correlating with superior catalytic performance in STD reactions. This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)-Project-ID 426888090-SFB 1441.

Keywords: Ceria; IRRAS; Noble metals(Pt, Pd); STD reactions; Surface science