Hydrogen Bond Formation of Brønsted Acid Sites in Zeolites

Schroeder C, Siozios V, Mück-Lichtenfeld C, Hunger M, Hansen MR, Koller H

Forschungsartikel (Zeitschrift) | Peer reviewed

Zusammenfassung

Brønsted acid sites (BAS) in dry aluminosilicate zeolites, also known asbridging OH-H groups, may form hydrogen bonds with other framework oxygen atoms, O,in addition to BAS that are free of such interactions. These are referred to as perturbed and unperturbed BAS, respectively. However, hydrogen bonding may occur only for specific geometric orientations between two framework oxygen atoms, allowing an OH-H···O interaction. To evaluate the possibility for such hydrogen bonding, we introduce an alignment angle κ that describes the angle between the Si-OH-Al bisector and the OH-O direction of a potential hydrogen-bonding donor-acceptor pair. A total of 27 zeoliteframework topologies were analyzed, and the relevance of this approach was subsequently demonstrated for H-ZSM-5 with two different Si/Al ratios. Here, it could be unequivocally shown by advanced solid-state NMR methods that the debated 1H NMR signalat∼6 ppm arises due to the formation of hydrogen-bonded BAS.

Details zur Publikation

FachzeitschriftChemistry of Materials (Chem. Mater.)
Jahrgang / Bandnr. / Volume32
Seitenbereich1564-1574
StatusVeröffentlicht
Veröffentlichungsjahr2020
Sprache, in der die Publikation verfasst istEnglisch
DOI10.1021/acs.chemmater.9b04714
Stichwörtersolid-state NMR; zeolites; acid sites; hydrogen bonds

Autor*innen der Universität Münster

Hansen, Michael Ryan
Professur für Physikalische Chemie (Prof. Hansen)
Koller, Hubert
Institut für Physikalische Chemie
Mück-Lichtenfeld, Christian
Center for Multiscale Theory and Computation (CMTC)
Schröder, Christian
Center for Soft Nanoscience (SoN)
Siozios, Vassilios
Institut für Physikalische Chemie