FTIR and (27)Al MAS NMR analysis of the effect of framework Al- and Si-defects in micro- and micro-mesoporous H-ZSM-5 on conversion of methanol to hydrocarbons

0372239 - ÚFCH JH 2012 RIV NL eng J - Článek v odborném periodiku
Sazama, Petr - Wichterlová, Blanka - Dědeček, Jiří - Tvarůžková, Zdenka - Musilová, Zuzana - Palumbo, L. - Sklenák, Štěpán - Gonsiorová, O.
FTIR and (27)Al MAS NMR analysis of the effect of framework Al- and Si-defects in micro- and micro-mesoporous H-ZSM-5 on conversion of methanol to hydrocarbons.
Microporous and Mesoporous Materials. Roč. 143, č. 1 (2011), s. 87-96. ISSN 1387-1811. E-ISSN 1873-3093
Grant CEP: GA ČR GP203/08/P593; GA AV ČR IAA400400812; GA AV ČR IAA400400904
Výzkumný záměr: CEZ:AV0Z40400503
Klíčová slova: micro-mesoporous H-ZSM-5 zeolite * framework defects * FTIR
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 3.285, rok: 2011

A series of micro- and micro-mesoporous H-ZSM-5 zeolites with highly regular and, on the other side, a defective framework were prepared by synthesis and post-synthesis treatment, and their activity was investigated in transformation of methanol to low olefins, aromatics and paraffins. (27)Al MAS NMR and FTIR spectroscopy of OH groups and C N groups of adsorbed d(3)-acetonitrile were used for analysis of the population of framework Al- and Si-related defective sites. Beside framework Al atoms in regular Td coordination, perturbed Td coordinated Al atoms and partly extra-framework Al species, and the internal Si-OH groups as Si-related defects were identified. The increase in the concentration of framework Al- and Si-defective sites in microporous H-ZSM-5 was manifested in methanol transformation in the increased yields of aromatics and paraffins, while highly regular framework preferred formation of low C(2) and C(3) olefins. The non-defective micro-mesoporous H-ZSM-5 prepared by alkaline and subsequent oxalic acid leaching of the zeolite with silanols typical for external crystal surface gave substantially longer catalyst life-time.
Trvalý link: http://hdl.handle.net/11104/0205602