Atomic Ordering and Sn Segregation in Pt-Sn Nanoalloys Supported on CeO2 Thin Films
Neitzel A, Kovacs G, Lykhach Y, Kozlov SM, Tsud N, Skala T, Vorokhta M, Matolin V, Neyman KM, Libuda J (2017)
Publication Status: Published
Publication Type: Journal article
Publication year: 2017
Journal
Publisher: SPRINGER/PLENUM PUBLISHERS
Book Volume: 60
Pages Range: 522-532
Journal Issue: 6-7
DOI: 10.1007/s11244-016-0709-5
Abstract
The stability and atomic ordering in Pt-Sn nanoalloys supported on CeO2 thin films have been studied by means of synchrotron radiation photoelectron spectroscopy and density functional calculations. Using CO molecules as a probe, we explored the development of the surface structure of supported Pt-Sn nanoalloys with respect to a reference Pt/CeO2 model system. We found a significant decrease in the density of CO adsorption sites on supported Pt-Sn nanoalloys caused by Sn segregation to the surface upon annealing. Additionally, we found that atomic ordering in Pt-Sn nanoalloys is driven by the balance between the surface segregation energy of Sn atoms and the energy of heteroatomic bond formation. Our calculations demonstrate a clear tendency for Sn segregation to the nanoalloy surface. For Pt105Sn35 and Pt1097Sn386 nanoparticles, we calculated a surface stoichiometry of Pt2Sn which is only slightly dependent on temperature in thermodynamic equilibrium. The analysis of Bader charges in Pt-Sn nanoalloys revealed a strong correlation between the charge and the coordination number of Sn atoms with respect to Pt neighbors. In particular, the magnitude of the charge transfer from Sn to Pt increases as a function of the Sn coordination number.
Authors with CRIS profile
Armin Neitzel
Lehrstuhl für Physikalische Chemie II
Yaroslava Lykhach
Lehrstuhl für Physikalische Chemie II
Jörg Libuda
Professur für Physikalische Chemie
Additional Organisation(s)
Involved external institutions
Univerzita Karlova v Praze / Charles University in Prague
Czech Republic (CZ)
Universitat de Barcelona (UB) / University of Barcelona
Spain (ES)
Czech Republic (CZ)
Universitat de Barcelona (UB) / University of Barcelona
Spain (ES)
How to cite
APA:
Neitzel, A., Kovacs, G., Lykhach, Y., Kozlov, S.M., Tsud, N., Skala, T.,... Libuda, J. (2017). Atomic Ordering and Sn Segregation in Pt-Sn Nanoalloys Supported on CeO2 Thin Films. Topics in Catalysis, 60(6-7), 522-532. https://dx.doi.org/10.1007/s11244-016-0709-5
MLA:
Neitzel, Armin, et al. "Atomic Ordering and Sn Segregation in Pt-Sn Nanoalloys Supported on CeO2 Thin Films." Topics in Catalysis 60.6-7 (2017): 522-532.
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