Acidic properties of SSZ-33 and SSZ-35 novel zeolites: a complex infrared and MAS NMR study

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F08%3A00315585" target="_blank" >RIV/61388955:_____/08:00315585 - isvavai.cz</a>

Výsledek na webu

—

DOI - Digital Object Identifier

—

Jazyk výsledku

angličtina

Název v původním jazyce

Acidic properties of SSZ-33 and SSZ-35 novel zeolites: a complex infrared and MAS NMR study

Popis výsledku v původním jazyce

Two novel zeolites SSZ-33 and SSZ-35 were investigated with respect to their acidic properties using different probe molecules to characterize the accessibility and acid strength of Lewis and Bronsted acid sites. Ammonia, pyridine, pivalonitrile, and acetonitrile-d(3) were used as probe molecules, and the results were correlated with Al-27 and H-1 magic angle spinning NMR. Both SSZ-33 and SSZ-35 zeolites were found to possess bridging Si-OH-Al groups of virtually uniform and high acid strength. For bothSSZ-33 and SSZ-35, there is the typical presence of highly disturbed OH groups (IR band around 3500 cm-1), which amounts to almost half of the overall Bronsted acidity. It was found that almost all bridging Si-OH-Al groups in SSZ-33 are located in the 12-MR rings. Both acetonitrile-d(3) and pyridine sorptions suggest the presence of two types of Lewis sites in SSZ-35, differing in acid strength and electron-acceptor properties, whereas in the SSZ-33 zeolite only one type is present.

Název v anglickém jazyce

Acidic properties of SSZ-33 and SSZ-35 novel zeolites: a complex infrared and MAS NMR study

Popis výsledku anglicky

Two novel zeolites SSZ-33 and SSZ-35 were investigated with respect to their acidic properties using different probe molecules to characterize the accessibility and acid strength of Lewis and Bronsted acid sites. Ammonia, pyridine, pivalonitrile, and acetonitrile-d(3) were used as probe molecules, and the results were correlated with Al-27 and H-1 magic angle spinning NMR. Both SSZ-33 and SSZ-35 zeolites were found to possess bridging Si-OH-Al groups of virtually uniform and high acid strength. For bothSSZ-33 and SSZ-35, there is the typical presence of highly disturbed OH groups (IR band around 3500 cm-1), which amounts to almost half of the overall Bronsted acidity. It was found that almost all bridging Si-OH-Al groups in SSZ-33 are located in the 12-MR rings. Both acetonitrile-d(3) and pyridine sorptions suggest the presence of two types of Lewis sites in SSZ-35, differing in acid strength and electron-acceptor properties, whereas in the SSZ-33 zeolite only one type is present.

Druh

D - Stať ve sborníku

CEP obor

CF - Fyzikální chemie a teoretická chemie

OECD FORD obor

—

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)<br>Z - Vyzkumny zamer (s odkazem do CEZ)

Rok uplatnění

2008

Kód důvěrnosti údajů

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

Název statě ve sborníku

Zeolites and Related Materials: Trends, Targets and Challenges

ISBN

978-0-444-53297-8

ISSN

—

e-ISSN

—

Počet stran výsledku

6

Strana od-do

—

Název nakladatele

Elsevier B.V./Ltd

Místo vydání

Oxford

Místo konání akce

Paris

Datum konání akce

1. 9. 2008

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

—