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

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F20%3A00537817" target="_blank" >RIV/61388955:_____/20:00537817 - isvavai.cz</a>

Alternative codes found

RIV/61389013:_____/20:00537817 RIV/62243136:_____/20:N0000035

Result on the web

<a href="http://hdl.handle.net/11104/0315652" target="_blank" >http://hdl.handle.net/11104/0315652</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/molecules25153434" target="_blank" >10.3390/molecules25153434</a>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10403 - Physical chemistry

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Molecules

ISSN

1420-3049

e-ISSN

—

Volume of the periodical

25

Issue of the periodical within the volume

15

Country of publishing house

CH - SWITZERLAND

Number of pages

20

Pages from-to

3434

UT code for WoS article

000559012800001

EID of the result in the Scopus database

2-s2.0-85088884203