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Diversity of adsorbed hydrogen on the TiC (001) surface at high coverages Piñero Vargas, Juan José Ramírez, Pedro J. Bromley, Stefan Thomas Illas i Riera, Francesc Viñes Solana, Francesc Rodríguez, José A. Hidrogenació Metalls de transició Catàlisi Química de superfícies Hydrogenation Transition metals Catalysis Surface chemistry 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. 2019-01-31T12:21:45Z 2019-11-15T06:10:18Z 2018-11-15 2019-01-31T12:21:46Z info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Versió postprint del document publicat a: https://doi.org/10.1021/acs.jpcc.8b07340 Journal of Physical Chemistry C, 2018, vol. 122 , num. 49, p. 28013-28020 https://doi.org/10.1021/acs.jpcc.8b07340 info:eu-repo/grantAgreement/EC/H2020/676580/EU//NoMaD (c) American Chemical Society , 2018 info:eu-repo/semantics/openAccess American Chemical Society Articles publicats en revistes (Ciència dels Materials i Química Física)