Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/112844
Title: Adsorption and dissociation of molecular hydrogen on orthorhombic β- Mo2C and cubic δ-MoC (001) surfaces
Author: Posada-Perez, Sergio
Viñes Solana, Francesc
Valero Montero, Rosendo
Rodríguez, J. A.
Illas i Riera, Francesc
Keywords: Espectroscòpia infraroja
Carburs
Dissociació (Química)
Hidrogenació
Termodinàmica
Física nuclear
Infrared spectroscopy
Carbides
Dissociation
Hydrogenation
Thermodynamics
Nuclear physics
Issue Date: 3-Oct-2016
Publisher: Elsevier B.V.
Abstract: Molybdenum carbides are increasingly used in heterogeneously catalyzed hydrogenation reactions, which imply the adsorption and dissociation of molecular hydrogen. Here a systematic density functional theory based study, including or excluding dispersion terms, concerning the interaction and stability of H2 with cubic δ-MoC(001) and orthorhombic β-Mo2C(001) surfaces is presented. In the latter case the two possible C or Mo terminations are considered. In addition, different situations for the H covered surfaces are examined. Computational results including dispersive forces predict as essentially spontaneous dissociation of H2 on β-Mo2C(001) independently of the surface termination, whereas on δ-MoC(001) molecular hydrogen dissociation implies a small but noticeable energy barrier. Furthermore, the ab initio thermodynamics formalism has been used to compare the stability of different H coverages. Finally, core level binding energies and vibrational frequencies are presented with the aim to assist the interpretation of yet unavailable data from X-ray photoelectron and infrared spectroscopies.
Note: Versió postprint del document publicat a: https://doi.org/10.1016/j.susc.2016.10.001
It is part of: Surface Science, 2016, vol. 656, p. 24-32
URI: http://hdl.handle.net/2445/112844
ISSN: 0039-6028
Appears in Collections:Publicacions de projectes de recerca finançats per la UE
Articles publicats en revistes (Ciència dels Materials i Química Física)

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