Effect of Alkali-Free Synthesis and Post-Synthetic Treatment on Acid Sites in Beta Zeolites

Mlekodaj, Kinga; Olszówka, Joanna Elżbieta; Tokárová, V.; Tabor, Edyta; Kašpárek, A.; Nováková, J.; Šťávová, G.; Gonsiorová, O.; Pelíšková, L.; Brus, Jiří; Pilař, Radim; Klein, Petr; Dědeček, Jiří

doi:https://dx.doi.org/10.3390/molecules25153434

Number of the records: 1

Effect of Alkali-Free Synthesis and Post-Synthetic Treatment on Acid Sites in Beta Zeolites

1.

SYSNO ASEP	0537817
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Effect of Alkali-Free Synthesis and Post-Synthetic Treatment on Acid Sites in Beta Zeolites
Author(s)	Mlekodaj, Kinga (UFCH-W)_{RID, ORCID} Olszówka, Joanna Elżbieta (UFCH-W)_ORCID Tokárová, V. (CZ) Tabor, Edyta (UFCH-W)_{RID, ORCID} Kašpárek, A. (CZ) Nováková, J. (CZ) Šťávová, G. (CZ) Gonsiorová, O. (CZ) Pelíšková, L. (CZ) Brus, Jiří (UMCH-V)_{RID, ORCID} Pilař, Radim (UFCH-W)_{RID, ORCID} Klein, Petr (UFCH-W)_{RID, ORCID} Dědeček, Jiří (UFCH-W)_{RID, ORCID}
Article number	3434
Source Title	Molecules. - : MDPI Roč. 25, č. 15 (2020)
Number of pages	20 s.
Language	eng - English
Country	CH - Switzerland
Keywords	al-27 mas ; nmr-spectroscopy ; bea-asterisk ; aluminum ; catalysis ; silicon ; nox ; dealumination ; framework ; pyridine ; beta zeolite ; alkali-free synthesis ; acid sites
Subject RIV	CF - Physical ; Theoretical Chemistry
OECD category	Physical chemistry
Subject RIV - cooperation	Institute of Macromolecular Chemistry - Macromolecular Chemistry
R&D Projects	GA18-20303S GA ČR - Czech Science Foundation (CSF)
	LM2015073 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
	EF16_013/0001821 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
Method of publishing	Open access
Institutional support	UFCH-W - RVO:61388955 ; UMCH-V - RVO:61389013
UT WOS	000559012800001
EID SCOPUS	85088884203
DOI	10.3390/molecules25153434
Annotation	Beta zeolites with Si/Al around 14 were prepared using three new alkali-free synthesis methods based on the application of amorphous aluminosilicate precursor and calcined in ammonia or air. All samples exhibit structural and textural properties of standard beta zeolite. Comprehensive study by(27)Al and(29)Si MAS NMR, together with FTIR adsorption of d(3)-acetonitrile and pyridine were used to characterize the influence of both the synthesis and calcination procedure on the framework Al atoms and related Bronsted and Lewis acid sites. While calcination in ammonia preserves all framework Al atoms, calcination in air results in 15% release of framework Al, but without restrictions of the accessibility of the beta zeolite channel system for bulky pyridine molecules. Terminal (SiO)(3)AlOH groups present in the hydrated zeolites were suggested as a precursor of framework Al-Lewis sites. Surprisingly, the mild dealumination of the air-calcined zeolites result in an increase of the concentration of Bronsted acid sites and a decrease of the total concentration of Lewis sites with the formation of the extra-framework ones.
Workplace	J. Heyrovsky Institute of Physical Chemistry
Contact	Michaela Knapová, michaela.knapova@jh-inst.cas.cz, Tel.: 266 053 196
Year of Publishing	2021
Electronic address	http://hdl.handle.net/11104/0315652

Number of the records: 1