Accessibility of the acid sites in dealuminated small-port mordenites studied by FTIR of co-adsorbed alkylpyridines and CO
| Autor: | Christian Fernandez, F. Fajula, Jean-Pierre Gilson, V.V. Yuschenko, Valérie Montouillout, Irina I. Ivanova, Nikolai Nesterenko, Frédéric Thibault-Starzyk |
|---|---|
| Přispěvatelé: | Department of Chemistry, Lomonosov Moscow State University, Lomonosov Moscow State University (MSU), Laboratoire catalyse et spectrochimie (LCS), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Laboratoire de Chimie de la Matière Condensée de Paris (site Paris VI) (LCMCP (site Paris VI)), Université Pierre et Marie Curie - Paris 6 (UPMC)-Collège de France (CdF (institution))-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), Laboratoire de Matériaux Catalytiques et Catalyse en Chimie Organique (LMCCCO), Université Montpellier 1 (UM1)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Centre National de la Recherche Scientifique (CNRS), Moscow State University, Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Inorganic chemistry
Infrared spectroscopy 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Molecular sieve 01 natural sciences Mordenite 0104 chemical sciences Catalysis chemistry.chemical_compound Adsorption chemistry Mechanics of Materials Pyridine [CHIM]Chemical Sciences General Materials Science Fourier transform infrared spectroscopy 0210 nano-technology Zeolite ComputingMilieux_MISCELLANEOUS |
| Zdroj: | Microporous and Mesoporous Materials Microporous and Mesoporous Materials, Elsevier, 2004, 71 (1-3), pp.157-166. ⟨10.1016/j.micromeso.2004.03.028⟩ Microporous and Mesoporous Materials, 2004, 71 (1-3), pp.157-166. ⟨10.1016/j.micromeso.2004.03.028⟩ |
| ISSN: | 1387-1811 |
| Popis: | A novel methodology for characterization and quantification the acidic sites of different accessibility has been developed for dealuminated zeolite catalysts. The method is based on probing the accessibility of acid sites by IR spectroscopy of adsorbed alkylpyridines, followed by the characterization of the non-accessible sites by IR spectroscopy of subsequently adsorbed CO. The gradual increase of the size of alkylpyridine probe molecules in a series of experiments allows a step-by-step characterization of the nature and strength of sites with different accessibility. The approach proposed was tested on the series of small-port mordenites dealuminated up to Si/Al ratios of 11, 12, 14 and 18 and characterized by various techniques including XRD, TPD-NH3, nitrogen adsorption–desorption, 1H MAS NMR and IR spectroscopy. It has been demonstrated that upon dealumination of the small-port MOR, two phenomena related to accessibility occur: (i) the acid sites in the side pockets become accessible for such probe molecules as pyridine due to the partial destruction of side pockets upon dealumination (ii) subsequently, the formation of secondary mesopore system due to further dealumination makes the zeolite crystals completely accessible to relatively bulky molecules such as lutidine, collidine, 2,6-di-tert-butylpyridine. |
| Databáze: | OpenAIRE |
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