Regeneration of LOHC dehydrogenation catalysts: In-situ IR spectroscopy on single crystals, model catalysts, and real catalysts from UHV to near ambient pressure

Journal article
(Original article)


Publication Details

Author(s): Amende M, Kaftan A, Bachmann P, Brehmer R, Preuster P, Koch M, Wasserscheid P, Libuda J
Journal: Applied Surface Science
Publisher: Elsevier
Publication year: 2016
Volume: 360
Pages range: 671-683
ISSN: 0169-4332


Abstract


The Liquid Organic Hydrogen Carrier (LOHC) concept offers an efficient route to store hydrogen using organic compounds that are reversibly hydrogenated and dehydrogenated. One important challenge towards application of the LOHC technology at a larger scale is to minimize degradation of Pt-based dehydrogenation catalysts during long-term operation. Herein, we investigate the regeneration of Pt/alumina catalysts poisoned by LOHC degradation. We combine ultrahigh vacuum (UHV) studies on Pt(111), investigations on well-defined Pt/AlO model catalysts, and near-ambient pressure (NAP) measurements on real core-shell Pt/AlO catalyst pellets. The catalysts were purposely poisoned by reaction with the LOHC perhydro-dibenzyltoluene (H18-MSH) and with dicyclohexylmethane (DCHM) as a simpler model compound. We focus on oxidative regeneration under conditions that may be applied in real dehydrogenation reactors. The degree of poisoning and regeneration under oxidative reaction conditions was quantified using CO as a probe molecule and measured by infrared reflection-absorption spectroscopy (IRAS) and diffuse reflectance Fourier transform IR spectroscopy (DRIFTS) for planar model systems and real catalysts, respectively. We find that regeneration strongly depends on the composition of the catalyst surface. While the clean surface of a poisoned Pt(111) single crystal is fully restored upon thermal treatment in oxygen up to 700 K, contaminated Pt/AlO model catalyst and core-shell pellet were only partially restored under the applied reaction conditions. Whereas partial regeneration on facet-like sites on supported catalysts is more facile than on Pt(111), carbonaceous deposits adsorbed at low-coordinated defect sites impede full regeneration of the Pt/AlO catalysts.



FAU Authors / FAU Editors

Amende, Maximilian
Professur für Physikalische Chemie
Bachmann, Philipp
Naturwissenschaftliche Fakultät
Brehmer, Richard
Lehrstuhl für Chemische Reaktionstechnik
Kaftan, Andre
Professur für Physikalische Chemie
Koch, Marcus
Lehrstuhl für Chemische Reaktionstechnik
Libuda, Jörg Prof. Dr.
Professur für Physikalische Chemie
Preuster, Patrick
Lehrstuhl für Chemische Reaktionstechnik
Wasserscheid, Peter Prof. Dr.
Lehrstuhl für Chemische Reaktionstechnik


Additional Organisation
Exzellenz-Cluster Engineering of Advanced Materials


How to cite

APA:
Amende, M., Kaftan, A., Bachmann, P., Brehmer, R., Preuster, P., Koch, M.,... Libuda, J. (2016). Regeneration of LOHC dehydrogenation catalysts: In-situ IR spectroscopy on single crystals, model catalysts, and real catalysts from UHV to near ambient pressure. Applied Surface Science, 360, 671-683. https://dx.doi.org/10.1016/j.apsusc.2015.11.045

MLA:
Amende, Maximilian, et al. "Regeneration of LOHC dehydrogenation catalysts: In-situ IR spectroscopy on single crystals, model catalysts, and real catalysts from UHV to near ambient pressure." Applied Surface Science 360 (2016): 671-683.

BibTeX: 

Last updated on 2019-19-02 at 15:24