Complex Analysis of the Aluminum Siting in the Framework of Silicon-Rich Zeolites. A Case Study on Ferrierites

0360036 - ÚFCH JH 2012 RIV US eng J - Journal Article
Dědeček, Jiří - Lucero, Melissa Jeanine - Li, Chengbin - Gao, Fei - Klein, Petr - Urbanová, Martina - Tvarůžková, Zdenka - Sazama, Petr - Sklenák, Štěpán
Complex Analysis of the Aluminum Siting in the Framework of Silicon-Rich Zeolites. A Case Study on Ferrierites.
Journal of Physical Chemistry C. Roč. 115, č. 22 (2011), s. 11056-11064. ISSN 1932-7447. E-ISSN 1932-7455
R&D Projects: GA AV ČR IAA400400812; GA AV ČR IAA400400908; GA AV ČR IAA400400904; GA ČR GA203/09/1627; GA ČR GP203/08/P593; GA AV ČR KAN100400702
Institutional research plan: CEZ:AV0Z40400503
Keywords : ferrierites * zeolites * aluminosilicates
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 4.805, year: 2011

We present a multistep method combining multispectroscopic experiments with DFT calculations to determine the complete Al distribution in silicon-rich zeolites, independent of the presence of Al–O–(Si–O)n–Al (n = 1, 2) sequences in their frameworks. 29Si MAS NMR spectroscopy is employed to confirm the absence of Al–O–Si–O–Al in the framework of silicon-rich zeolites while 27Al 3Q MAS NMR spectroscopy and DFT computations of 27Al isotropic chemical shifts serve to determine the locations of isolated Al atoms. The maximum ion-exchange capacity of zeolites for [Co2+(H2O)6]2+ reveals the presence of close Al atoms (i.e., those Al atoms which are able to balance [Co2+(H2O)6]2+ ions). Then visible spectroscopy of the bare Co(II) ion in the dehydrated zeolite of the samples with close Al is utilized to identify the locations of the corresponding Al–O–(Si–O)2–Al pairs in a ring.
Permanent Link: http://hdl.handle.net/11104/0197685