Počet záznamů: 1
On the location of iron and aluminium atoms in thermally activated AlMCM-58 and FeMCM-58 zeolites
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SYSNO ASEP 0375929 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název On the location of iron and aluminium atoms in thermally activated AlMCM-58 and FeMCM-58 zeolites Tvůrce(i) Gil, B. (PL)
Marszalek, B. (PL)
Adamski, A. (PL)
Olejniczak, Z. (PL)
Kubů, Martin (UFCH-W) RID
Čejka, Jiří (UFCH-W) RID, ORCID, SAIZdroj.dok. Microporous and Mesoporous Materials. - : Elsevier - ISSN 1387-1811
Roč. 151, MAR 2012 (2012), s. 339-345Poč.str. 7 s. Jazyk dok. eng - angličtina Země vyd. NL - Nizozemsko Klíč. slova MCM-58 ; heteroatom location ; IR, EPR and NMR spectroscopy Vědní obor RIV CF - Fyzikální chemie a teoretická chemie CEP GAP106/11/0819 GA ČR - Grantová agentura ČR GD203/08/H032 GA ČR - Grantová agentura ČR CEZ AV0Z40400503 - UFCH-W (2005-2011) UT WOS 000300747000044 DOI 10.1016/j.micromeso.2011.10.014 Anotace FTIR study of iron and aluminium forms of zeolite MCM-58 showed that location of heteroatoms in this IFR structure depends on the type of heteroatom. The combination of the pyridine and CO adsorption allowed determination of the concentration of hydroxyls in the 12- and 5/6-rings. Both Fe and Al are generating hydroxyls pointing towards either 12-ring or 5/6-rings but the former are located in positions giving Si–OH–Fe hydroxyls pointing mainly to the 12-rings while the latter gives rise to the Si–OH–Al groups pointing primarily to the narrower 5- and 6-rings. (Al)MCM-58 undergoes only minor dehydroxylation associated with the acid sites even at temperatures as high as 700 °C, which indicates unique stabilization of Al atoms in the IFR structure. In the case of (Fe)MCM-58, dehydroxylation is more extensive. Furthermore the OH located in the 5/6-rings dehydroxylate at lower temperatures than those in the 12-rings. The study also demonstrates that the concentration of the framework and extraframework iron atoms can be determined by a simple method based on pyridine adsorption followed by IR spectroscopy. Pracoviště Ústav fyzikální chemie J.Heyrovského Kontakt Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Rok sběru 2013
Počet záznamů: 1