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Mutable Lewis and Bronsted Acidity of Aluminated SBA-15 as Revealed by NMR of Adsorbed Pyridine-(15)N
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SYSNO ASEP 0365144 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Mutable Lewis and Bronsted Acidity of Aluminated SBA-15 as Revealed by NMR of Adsorbed Pyridine-(15)N Author(s) Gurinov, A. A. (RU)
Rozhkova, Yu. A. (RU)
Zukal, Arnošt (UFCH-W) RID
Čejka, Jiří (UFCH-W) RID, ORCID, SAI
Shenderovich, I, G. (RU)Source Title Langmuir. - : American Chemical Society - ISSN 0743-7463
Roč. 27, č. 19 (2011), s. 12115-12123Number of pages 9 s. Language eng - English Country US - United States Keywords 15N NMR ; post-synthesis alumination ; phase Beckmann rearrangement Subject RIV CF - Physical ; Theoretical Chemistry R&D Projects KAN100400701 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR) GA203/08/0604 GA ČR - Czech Science Foundation (CSF) CEZ AV0Z40400503 - UFCH-W (2005-2011) UT WOS 000295187300050 DOI 10.1021/la2017566 Annotation 1H and variable-temperature (15)N NMR techniques have been used to study the effect of the gradual alumination of SBA-15 on the structure and adsorption properties of this mesoporous material. The interpretation of experimental spectra suggests that aluminum chlorhydrol most effectively reacts with silica surfaces in the confinement of the cavities of rough mesopore walls, instead of forming a homogeneous aluminum film. This first leads to a gradual filling of the cavities and finally results in aluminum islands on the inner surfaces of mesopores. In the sample with a Si/Al atomic ratio of 4.1, up to half of the inner surface area of the mesopores is covered with aluminum. The alumination produces Bronsted acid sites attributed to silanol groups interacting with aluminum but does not affect the proton-donating ability of isolated silanol groups. At high Si/Al ratios, the surface contains only one type of Lewis site attributed to tetracoordinated aluminum. Workplace J. Heyrovsky Institute of Physical Chemistry Contact Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196 Year of Publishing 2012
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