Dresden 2017 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 87: Metal Substrates: Structure, Epitaxy and Growth

O 87.1: Hauptvortrag

Donnerstag, 23. März 2017, 10:30–11:00, WIL C307

Structure and redox dynamics of ultrathin ceria films and nanostructures — •Jan Ingo Flege — Institute of Solid State Physics, University of Bremen, Bremen, Germany — MAPEX Center for Materials and Processes, University of Bremen, Bremen, Germany

Cerium oxide is of considerable importance for a wide range of technological applications including, e g., energy harvesting, storage, and conversion, chemical sensing, and heterogeneous catalysis. Epitaxially grown ceria thin films and nanostructures represent important model systems allowing for the investigation of their peculiar materials properties using surface science methodology. In this presentation, I will focus on the growth and characterization of cerium oxide ultrathin films and microparticles on transition metal surfaces and the subsequent monitoring of their structural and chemical modifications in reactive environments using low-energy electron microscopy and related methods. Starting from the frequently employed ceria(111)/Ru(0001) inverse model catalyst [1], it will be demonstrated that nanoscale structural transformations that occur upon chemical reduction, thermal annealing, or reoxidation can be followed in real-time. Furthermore, it will be shown that in situ probing during epitaxial growth facilitates a deeper understanding of the prevailing mechanisms, which may be exploited to selectively synthesize ceria(001) nanostructures and microparticles [2, 3] for model catalytic studies.

[1] D. C. Grinter et al., Appl. Catal., B 197, 286 (2016).

[2] J. Höcker et al., J. Phys. Chem. C 120, 4895 (2016).

[3] J. I. Flege et al., Nanoscale 8, 10849 (2016).