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O: Fachverband Oberflächenphysik
O 78: Heterogeneous Catalysis and Surface Dynamics II
O 78.8: Talk
Thursday, March 30, 2023, 12:15–12:30, TRE Phy
Structural and Electronic Properties of Iron Nanoparticles onto Well-Defined Ceria Thin Films — •Lesia Piliai1, Mykhailo Vorokhta1, Peter Matvija1, Tomáš Skála1,2, Ivan Khalakhan1, and Iva Matolínová1 — 1Charles University, Prague, Czech Republic — 2Elettra-Sincrotrone, Elettra-Sincrotrone, Italy
The interaction of iron with ceria using model Fe/ceria systems consisting of Fe nanoparticles vapor deposited on well-ordered CeOx(x=1,5;2) thin films grown on Cu(111) has been investigated by X-ray photoelectron spectroscopy (XPS), synchrotron radiation photoemission spectroscopy (SRPES), and scanning tunneling microscopy (STM). The Fe atoms are oxidized to Fe3+ and Fe2+ species upon deposition on CeO2 at 300 K at the cost of the reduction of Ce4+ to Ce3+. With increasing the Fe coverage, the concentration of Ce3+ increases monotonically. The notable growth of Fe2+ species was observed upon deposition on CeO2 at 300 K, but Fe3+ species remain predominant in Fe/CeOx systems. Our studies demonstrate that in comparison with other transition metals, Fe remains oxidized on ceria even at higher coverage and exhibits a small particle size, likely arising from strong metal*support interactions. Combining the SRPES and STM data suggests that annealing to higher temperatures leads to the formation of an iron-ceria solid solution. These results illustrate that Fe modifies both the electronic and structural properties of ceria depending on external conditions.