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Formation of Mesopores in USY Zeolites: A Case Revisited |
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| Authors: | Wolfgang Lutz Dr. Rolf Kurzhals Galina Kryukova Dirk Enke Manfred Weber Detlef Heidemann |
| Affiliation: | 1. Email:lutz@ btu‐lc.fta‐berlin.de;4. Lehrstuhl für Luftchemie und Luftreinhaltung, Brandenburgische Technische Universit?t Cottbus, Labor Berlin,Volmerstra?e 13,12489 Berlin, Germany;5. Süd‐Chemie Zeolites GmbH, Tricat‐Stra?e, 06803 Bitterfeld‐Wolfen, Germany;6. Boreskov Institute of Catalysis SB RAS, Pr. Lavrentieva 5, 630090 Novosibirsk, Russia, present address: GNF e.V., Volmerstr. 7 B, 12489 Berlin, Germany;7. Institut für Chemie, Martin‐Luther‐Universit?t Halle‐Wittenberg, Kurt‐Mothes‐Stra?e 2,06120 Halle, Germany;8. Process Technology Development GmbH – SCW, Justus‐von‐Liebig‐Stra?e 6, 12489 Berlin, Germany;9. Institut für Chemie, Humboldt‐Universit?t zu Berlin, Brook‐Taylor‐Str. 2, 12489 Berlin, Germany |
| Abstract: | Steaming of NH4Y zeolite at 723 K and 873 K is accompanied by the formation of extra‐framework amorphous aluminosilicate and silica gel in addition to earlier observed extra‐framework aluminum species. Their occurrence is directly associated with the formation of mesopores. Bulk (intracrystalline) mesopores occur inside the crystallite nuclei and surface (intercrystalline) mesopores are located nearby the crystallite surface. Corrosion of the zeolite framework results in a loss of crystallinity and, consequently, decreased catalytic activity of the USY catalysts synthesized. Analysis of the reasons of mesopore formation may help to reduce these disadvantages. |
| Keywords: | Zeolites Dealumination Faujasite Mesoporous materials Aluminum |