Título:
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Diversity of adsorbed hydrogen on the TiC (001) surface at high coverages
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Autor/a:
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Piñero, Juan José; Ramírez, Pedro J.; Bromley, Stefan Thomas; Illas i Riera, Francesc; Viñes Solana, Francesc; Rodriguez, J.A.
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Otros autores:
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Universitat de Barcelona |
Abstract:
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The catalyzed dissociation of molecular hydrogen on the surfaces of diverse materials is currently widely studied due to its importance in a broad range of hydrogenation reactions that convert noxious exhaust products and/or greenhouse gases into added-value greener products such as methanol. In the search for viable replacements for expensive late transition metal catalysts TiC has been increasingly investigated as a potential catalyst for H2 dissociation. Here, we report on a combination of experiments and density functional theory calculations on the well-defined TiC(001) surface revealing that multiple H and H2 species are available on this substrate, with different binding configurations and adsorption energies. Our calculations predict an initial occupancy of H atoms on surface C atom sites, which then enables the subsequent stabilization of H atoms on top of surface Ti atoms. Further H2 can be also molecularly adsorbed over Ti sites. These theoretical predictions are in full accordance with information extracted from X-ray photoemission spectroscopy and temperature-programmed desorption experiments. The experimental results show that at high coverages of hydrogen there is a reconstruction of the TiC(001) surface which facilitates the binding of the adsorbate. |
Materia(s):
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-Hidrogenació -Metalls de transició -Catàlisi -Química de superfícies -Hydrogenation -Transition metals -Catalysis -Surface chemistry |
Derechos:
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(c) American Chemical Society , 2018
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Tipo de documento:
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Artículo Artículo - Versión aceptada |
Editor:
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American Chemical Society
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