title: Shape changes of supported Rh nanoparticles during oxidation and reduction cycles.
abstract: The microscopic insight into how and why catalytically active nanoparticles change their shape during oxidation and reduction reactions is a pivotal challenge in the fundamental understanding of heterogeneous catalysis. We report an oxygen-induced shape transformation of rhodium nanoparticles on magnesium oxide (001) substrates that is lifted upon carbon monoxide exposure at 600 kelvin. A Wulff analysis of high-resolution in situ x-ray diffraction, combined with transmission electron microscopy, shows that this phenomenon is driven by the formation of a oxygen-rhodium-oxygen surface oxide at the rhodium nanofacets. This experimental access into the behavior of such nanoparticles during a catalytic cycle is useful for the development of improved heterogeneous catalysts.
authors.affiliation: Max-Planck-Institut für Metallforschung, Heisenbergstrasse 3, D-70569 Stuttgart, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Nolte
authors.forename: A
authors.initials: A
authors.lastname: Stierle
authors.forename: N Y
authors.initials: NY
authors.lastname: Jin-Phillipp
authors.forename: N
authors.initials: N
authors.lastname: Kasper
authors.forename: T U
authors.initials: TU
authors.lastname: Schulli
authors.forename: H
authors.initials: H
authors.lastname: Dosch