Počet záznamů: 1  

Incorporation of Aluminum and Iron into the ZSM-12 Zeolite: Synthesis and Characterization of Acid Sites

  1. 1.
    0181507 - UFCH-W 20020245 RIV CZ eng J - Článek v odborném periodiku
    Košová, Gabriela - Čejka, Jiří
    Incorporation of Aluminum and Iron into the ZSM-12 Zeolite: Synthesis and Characterization of Acid Sites.
    Collection of Czechoslovak Chemical Communications. Roč. 67, - (2002), s. 1760-1778. ISSN 0010-0765
    Grant CEP: GA AV ČR IAA4040001
    Výzkumný záměr: CEZ:AV0Z4040901
    Klíčová slova: ZSM-12 * aluminum * iron
    Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
    Impakt faktor: 0.848, rok: 2002

    Zeolite ZSM-12 with aluminum and iron in the framework was synthesized in a broad range of Si/Al (Fe) ratios using methyltriethylammonium bromide as structure-directing agent with the aim to characterize the type and concentration of acid sites in dependence on Si/Al (Fe) ratios and calcination procedures. It was shown that the minimum Si/Al ratio achieved for (Al)ZSM-12 is around 35, which is very close to minimum Si/Fe ratio of about 37 for (Fe)ZSM-12. The rate of crystallization of (Al) and (Fe)ZSM-12 depends on the concentration of Al and Fe in the reaction mixture of these trivalent cations, the slower was the apparent crystallization rate. It is suggested that the crystallization rate is controlled by the number of nucleation centers, which depends on the amount of trivalent cations (Al, Fe) . Zeolites (Al) and (Fe)ZSM-12 were calcined under a variety of carefully controlled conditions to investigate the resulting concentration of Broensted and Lewis acid sites.
    Trvalý link: http://hdl.handle.net/11104/0078066

     
     

Počet záznamů: 1  

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