Chromium sites in zeolite framework: Chromyl or chromium hydroxyl groups?
| Autor: | Tetsuya Shishido, Frank De Proft, Mazharul M. Islam, Gabriella Skara, Stanislaw Dzwigaj, Frederik Tielens |
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| Přispěvatelé: | General Chemistry, Chemistry, Laboratoire de Réactivité de Surface (LRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physico-Chimie des Surfaces (LPCS), Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Mulliken Center for Theoretical Chemistry, Rheinische Friedrich-Wilhelms-Universität Bonn, Algemene Chemie, Vrije Universiteit Brussel (VUB), Université libre de Bruxelles (ULB), Department of Molecular Engineering, Kyoto University [Kyoto], Kyoto University |
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Chromium
inorganic chemicals Chromium sites in zeolite framework Inorganic chemistry Ab initio chemistry.chemical_element Protonation 02 engineering and technology 010402 general chemistry 01 natural sciences Deprotonation otorhinolaryngologic diseases Molecule General Materials Science Fourier transform infrared spectroscopy Zeolite Phase diagram Periodic DFT technology industry and agriculture [CHIM.CATA]Chemical Sciences/Catalysis General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences FT-IR chemistry Mechanics of Materials DR UV-vis 0210 nano-technology |
| Zdroj: | Microporous and Mesoporous Materials Microporous and Mesoporous Materials, Elsevier, 2012, 159, pp.66-73. ⟨10.1016/j.micromeso.2012.02.046⟩ Microporous and Mesoporous Materials, 2012, 159, pp.66-73. ⟨10.1016/j.micromeso.2012.02.046⟩ Vrije Universiteit Brussel |
| ISSN: | 1387-1811 |
| Popis: | International audience; A combined experimental and ab initio periodic DFT calculation on the structure and stability of different chromium-substituted zeolite models are presented. Experimental investigation by XRD, FT-IR and UV-vis show the presence of chromium in SiBEA zeolite. The favorable chromium sites are characterized by their calculated geometrical parameters, energetics, vibrational frequencies and protonation/deprotonation energies. The theoretical vibrational frequencies are compared with experimental FT-IR measurements. A phase diagram was constructed on the basis of calculated total energies of the optimized structures. Cr(III) is stabilized in the zeolite framework as a tri-coordinated site. Cr sites are predicted to be more acidic than group V containing zeolites. Dehydration of the site leads to the formation of a Cr(VI) containing a Crdouble bond; length as m-dashO group. These results are fully consistent with experimental data and allow the identification of the molecular structure of chromium sites in a zeolite framework. |
| Databáze: | OpenAIRE |
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