Dehydrogenation of Dodecahydro-N-ethylcarbazole on Pd/Al2O3 Model Catalysts

Beitrag in einer Fachzeitschrift


Details zur Publikation

Autor(en): Sobota M, Nikiforidis I, Amende M, Sanmartίn Zanón B, Staudt T, Höfert O, Lykhach Y, Papp C, Hieringer W, Laurin M, Assenbaum D, Wasserscheid P, Steinrück HP, Görling A, Libuda J
Zeitschrift: Chemistry - A European Journal
Verlag: Wiley-VCH Verlag
Jahr der Veröffentlichung: 2011
Band: 17
Heftnummer: 41
Seitenbereich: 11542-11552
ISSN: 0947-6539


Abstract


To elucidate the dehydrogenation mechanism of dodecahydro-N-ethylcarbazole (H -NEC) on supported Pd catalysts, we have performed a model study under ultra high vacuum (UHV) conditions. H -NEC and its final dehydrogenation product, N-ethylcarbazole (NEC), were deposited by physical vapor deposition (PVD) at temperatures between 120 K and 520 K onto a supported model catalyst, which consisted of Pd nanoparticles grown on a well-ordered alumina film on NiAl(110). Adsorption and thermally induced surface reactions were followed by infrared reflection absorption spectroscopy (IRAS) and high-resolution X-ray photoelectron spectroscopy (HR-XPS) in combination with density functional theory (DFT) calculations. It was shown that, at 120 K, H -NEC adsorbs molecularly both on the Al O /NiAl(110) support and on the Pd particles. Initial activation of the molecule occurs through C-H bond scission at the 8a- and 9a-positions of the carbazole skeleton at temperatures above 170 K. Dehydrogenation successively proceeds with increasing temperature. Around 350 K, breakage of one C-N bond occurs accompanied by further dehydrogenation of the carbon skeleton. The decomposition intermediates reside on the surface up to 500 K. At higher temperatures, further decay to small fragments and atomic species is observed. These species block most of the absorption sites on the Pd particles, but can be oxidatively removed by heating in oxygen at 600 K, fully restoring the original adsorption properties of the model catalyst. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.



FAU-Autoren / FAU-Herausgeber

Amende, Maximilian
Lehrstuhl für Physikalische Chemie II
Görling, Andreas Prof. Dr.
Lehrstuhl für Theoretische Chemie
Hieringer, Wolfgang PD Dr.
Lehrstuhl für Theoretische Chemie
Höfert, Oliver
Lehrstuhl für Physikalische Chemie II
Laurin, Mathias Dr.
Lehrstuhl für Physikalische Chemie II
Libuda, Jörg Prof. Dr.
Professur für Physikalische Chemie
Lykhach, Yaroslava
Lehrstuhl für Physikalische Chemie II
Nikiforidis, Ioannis
Lehrstuhl für Theoretische Chemie
Papp, Christian PD Dr.
Lehrstuhl für Physikalische Chemie II
Sobota, Marek
Graduiertenzentrum der FAU
Steinrück, Hans-Peter Prof. Dr.
Lehrstuhl für Physikalische Chemie II
Wasserscheid, Peter Prof. Dr.
Lehrstuhl für Chemische Reaktionstechnik


Zusätzliche Organisationseinheit(en)
Exzellenz-Cluster Engineering of Advanced Materials


Zitierweisen

APA:
Sobota, M., Nikiforidis, I., Amende, M., Sanmartίn Zanón, B., Staudt, T., Höfert, O.,... Libuda, J. (2011). Dehydrogenation of Dodecahydro-N-ethylcarbazole on Pd/Al2O3 Model Catalysts. Chemistry - A European Journal, 17(41), 11542-11552. https://dx.doi.org/10.1002/chem.201101311

MLA:
Sobota, Marek, et al. "Dehydrogenation of Dodecahydro-N-ethylcarbazole on Pd/Al2O3 Model Catalysts." Chemistry - A European Journal 17.41 (2011): 11542-11552.

BibTeX: 

Zuletzt aktualisiert 2018-11-08 um 03:11