Berlin 2024 – scientific programme
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O: Fachverband Oberflächenphysik
O 33: Poster: Supported Nanoclusters and Catalysis
O 33.10: Poster
Tuesday, March 19, 2024, 18:00–20:00, Poster C
Oxide formation and oxide/metal interaction in CeOx/Ni(111) — •Dominic Guttmann, Björn Riedel, 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 for methane to methanol conversion, making them very promising for applications within a sustainable economy. Possibly, their activity may be strongly enhanced due to the facile exchange between Ce4+ and Ce3+ states, with the latter likely responsible for activating O-H and C-H bonds. Here, we aim to unravel the complex metal-oxide interactions in the inverse CeOx/Ni(111) system under oxidizing and reducing environments. Using low-energy electron diffraction (LEED) we find that the CeOx(111) grown by reactive molecular beam epitaxy preferentially aligns with the main directions of the Ni(111) substrate or is azimuthally rotated by ±10∘. By using X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS), we find that less NiO is formed during deposition of CeOx than when it is held without ceria at the same conditions (O2 partial pressure and temperature). Finally, we observe a complex behavior of the cerium and nickel oxidation states when exposing the system to O2 or H2 atmospheres.
Keywords: Inverse model catalyst; Ceria; XPS; LEED