Adsorption and reaction of cyclohexene on a Ni(111) surface

Papp C, Denecke R, Steinrück HP (2007)

Publication Type: Journal article

Publication year: 2007

Journal

Langmuir American Chemical Society

Original Authors: Papp C., Denecke R., Steinrück H.-P.

Publisher: American Chemical Society

Book Volume: 23

Pages Range: 5541-5547

Journal Issue: 10

DOI: 10.1021/la0635909

Abstract

We studied the adsorption and reaction of cyclohexene (CH ) on Ni(111) at different temperatures with highresolution in-situ X-ray photoelectron spectroscopy (HR-XPS). For exposure at 125 K, we find intact cyclohexene with two distinct C Is signals at 283.3 and 284.2 eV, due to the nonequivalent carbon atoms in the molecule. The energetic separation is significantly increased relative to the gas-phase value, due to the interaction with the substrate. Upon exposure at 210 K, complete dehydrogenation of cyclohexene to benzene (CH) and hydrogen is observed; coverage-dependent changes of the benzene adsorption site occur in a way similar to those for pure benzene layers, which indicates a phase separation in benzene and hydrogen islands. The thermal evolution of the adsorbed layers was studied by temperature-programmed (TP-) XPS and temperature-programmed desorption spectroscopy (TPD). Upon heating, the benzene + hydrogen layer formed at 210 K shows a coverage-dependent reorientation of the benzene molecules during partial desorption. The cyclohexene layer adsorbed at 125 K only shows partial conversion of cyclohexene to benzene and hydrogen upon heating to 185 or 210 K, with the remaining cyclohexene being stable up to ∼300 K. We propose that upon heating these molecules are stabilized by coadsorbed benzene and hydrogen; furthermore, the mobility of benzene and hydrogen in this coadsorbed layer is reduced, so that no phase separation can occur. © 2007 American Chemical Society.

Authors with CRIS profile

Christian Papp Lehrstuhl für Physikalische Chemie II Hans-Peter Steinrück Lehrstuhl für Physikalische Chemie II

Involved external institutions

Universität Leipzig DE Germany (DE)

How to cite

APA:

Papp, C., Denecke, R., & Steinrück, H.-P. (2007). Adsorption and reaction of cyclohexene on a Ni(111) surface. Langmuir, 23(10), 5541-5547. https://doi.org/10.1021/la0635909

MLA:

Papp, Christian, Reinhard Denecke, and Hans-Peter Steinrück. "Adsorption and reaction of cyclohexene on a Ni(111) surface." Langmuir 23.10 (2007): 5541-5547.

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