Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 41: Heterogeneous Catalysis II
O 41.1: Vortrag
Dienstag, 18. März 2025, 14:00–14:15, H8
Oxide growth and oxide/metal interaction in CeOx/Ni(111) — •Dominic Guttmann, Raquel Sánchez-Barquilla, Carlos Morales, and Jan Ingo Flege — Applied Physics and Semiconductor Spectroscopy, Brandenburg University of Technology Cottbus-Senftenberg, Cottbus 03046, Germany
Ni/ceria catalysts exhibit a high activity and selectivity for CO2 methanation, making them very promising candidates for applications within a sustainable economy. The redox properties of cerium oxide allow it to readily switch between Ce4+ and Ce3+ states, facilitating CO2 activation and conversion. We have studied the so-called strong metal-metal oxide interactions in the inverse catalyst configuration CeOx/Ni(111) prepared by reactive molecular beam epitaxy in an oxygen atmosphere. Under specific growth conditions, the CeOx (111)-oriented islands of different heights preferentially align in registry with the Ni(111) surface or are rotated azimuthally by ±10∘, as observed by low-energy electron diffraction. Analysis by X-ray photoelectron spectroscopy reveals that during growth, partial oxidation of the Ni(111) surface leads to the formation of a NiO interface layer between the CeOx islands and Ni substrate, resulting in a complex CeOx(111)/NiO(111)/Ni(111) system with significant oxide-metal interactions. Finally, when we expose the system to H2, O2, and CO2 atmospheres, we observe a complex behavior of the cerium and nickel oxidation states, which correlate with morphological changes in the oxide islands.
Keywords: CeO2; Ni(111); model catalyst; XPS; LEED