Dresden 2017 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 31: Oxide and Insulator Surfaces: Structure, Epitaxy and Growth I
O 31.6: Vortrag
Dienstag, 21. März 2017, 11:45–12:00, WIL C107
Surface Faceting and Reconstruction of Ceria Nanoparticles — •Chengwu Yang1, Xiaojuan Yu1, Stefan Heißler1, Alexei Nefedov1, Sara Colussi2, Jordi Llorca3, Alessandro Trovarelli2, Yuemin Wang1, and Christof Wöll1 — 1Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany. — 2Dipartimento Politecnico, Università di Udine, via cotonificio 108 - 33100 Udine, Italy. — 3Institut de Tècniques Energètiques and Centre for Research in Nanoengineering, Universitat Politècnica de Catalunya, 808028 Barcelona, Spain.
The surface atomic arrangement of metal oxides strongly determines their physical and chemical properties, and the ability to control and optimize structural parameters is of crucial importance for many applications, in particular in heterogeneous catalysis and photocatalysis. While for macroscopic single crystals such structure determinations can be carried out using established methods, for nanoparticles (NPs) this is a challenging task. Here, we report the results of an IR spectroscopic study where CO is used as a probe molecule to determine the structure of surfaces exposed by rod-shaped ceria NPs. After calibrating the CO stretch frequencies using results obtained for different ceria single crystal surfaces we find that the rod-shaped NPs actually restructure and expose {111} nanofacets. This finding has important consequences for understanding the controversial surface chemistry of these catalytically highly active ceria NPs and paves the way for a predictive, rational design of catalytic materials at nanoscale.