Počet záznamů: 1  

(Al)MCM-41 Molecular Sieves. Aluminium Distribution, Uniformity and Structure of Inner Surface

  1. 1.
    0181720 - UFCH-W 20030154 RIV CZ eng J - Článek v odborném periodiku
    Dědeček, Jiří - Žilková, Naděžda - Kotrla, Josef - Čejka, Jiří
    (Al)MCM-41 Molecular Sieves. Aluminium Distribution, Uniformity and Structure of Inner Surface.
    Collection of Czechoslovak Chemical Communications. Roč. 68, č. 10 (2003), s. 1998-2018. ISSN 0010-0765
    Grant CEP: GA ČR GA104/02/0571; GA AV ČR IAA4040001; GA AV ČR IBS4040017
    Grant ostatní: Volkswagen Stiftung(DE) I/75886
    Výzkumný záměr: CEZ:AV0Z4040901
    Klíčová slova: molecular sieves * mesoporous materials * Vis spectroscopy
    Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
    Impakt faktor: 1.041, rok: 2003

    The effect of the framework Al content and synthesis procedure on the number of framework Al atoms located on the surface of (Al)MCM-41 channels and the distribution of the Al atoms between single Al atoms and various Al-O-(Si-O)1,2-Al species was investigated. The total number of accessible framework Al atoms on the channel surface was obtained from the ion exchange capacity for Na+ ions and pyridine adsorption. The number of Al pairs on the surface and their distribution between different local arrangements of the channel surface was estimated using Vis spectroscopy of Co2+ ions. At low framework Al contents, Al atoms occupy only accessible T sites on the surface of the channel walls. In aluminium-rich (Al)MCM-41, a significant part of Al atoms is incorporated inside the channel walls and these Al atoms do not form cationic sites. Al atoms on the wall surface preferentially form Al-O-(Si-O)1,2-Al sequences, enabling siting of divalent cations.
    Trvalý link: http://hdl.handle.net/11104/0078249

     
     

Počet záznamů: 1  

  Tyto stránky využívají soubory cookies, které usnadňují jejich prohlížení. Další informace o tom jak používáme cookies.