Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 8: Surface Chemical Reactions and Heterogeneous Catalysis I

O 8.3: Vortrag

Montag, 11. März 2013, 11:00–11:15, H33

Dehydrogenation of dodecahydro-N-Ethylcarbazole on Pt(111) — •Christoph Gleichweit, Max Amende, Stefan Schernich, Wei Zhao, Oliver Höfert, Jörg Libuda, Hans-Peter Steinrück, and Christian Papp — Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen (Germany)

The dehydrogenation of the liquid organic hydrogen carrier dodecahydro-N-ethylcarbazole (H₁₂-NEC) on Pt(111) was studied by high-resolution X-ray photoelectron spectroscopy (HR-XPS) in order to elucidate its dehydrogenation mechanism. H₁₂-NEC was adsorbed under ultra hight vacuum (UHV) conditions by physical vapor deposition, and subsequently the reaction was monitored during heating. Although the molecules are quite complex, we identified the reaction steps after detailed analysis of the C1s and N1s core levels. During adsorption at low temperatures the development of monolayer and multilayer peaks was observed. Interestingly the N1s peak assigned to the multilayer is found at lower binding energy than the monolayer peak. When heating the sample continuously, the multilayer desorbs up to temperatures of about 285 K while the signature of the monolayer increases due to decreased damping. Subsequently, the dehydrogenation of the H₁₂-NEC to NEC follows successively in the range of 280 K to 500 K. Above 430 K the dealkylation reaction of the NEC to carbazole is observed. Upon further heating to 1000 K decomposition to adsorbed carbon takes place. We acknowledge the cluster of excellence “Engineering of Advanced Materials”.