The effect of the zeolite pore size on the Lewis acid strength of extra-framework cations

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F16%3A00461872" target="_blank" >RIV/61388955:_____/16:00461872 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/16:10325314 RIV/00216275:25310/16:39902156

Výsledek na webu

<a href="http://dx.doi.org/10.1039/C6CP03343A" target="_blank" >http://dx.doi.org/10.1039/C6CP03343A</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/C6CP03343A" target="_blank" >10.1039/C6CP03343A</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The effect of the zeolite pore size on the Lewis acid strength of extra-framework cations

Popis výsledku v původním jazyce

The catalytic activity and the adsorption properties of zeolites depend on their topology and composition. For a better understanding of the structure–activity relationship it is advantageous to focus just on one of these parameters. Zeolites synthesized recently by the ADOR protocol offer a new possibility to investigate the effect of the channel diameter on the adsorption and catalytic properties of zeolites: UTL, OKO, and PCR zeolites consist of the same dense 2D layers (IPC-1P) that are connected with different linkers (D4R, S4R, O-atom, respectively) resulting in the channel systems of different sizes (14R 12R, 12R 10R, 10R 8R, respectively). Consequently, extra-framework cation sites compensating charge of framework Al located in these dense 2D layers (channel-wall sites) are the same in all three zeolites. Therefore, the effect of the zeolite channel size on the Lewis properties of the cationic sites can be investigated independent of other factors determining the quality of Lewis sites. UTL, OKO, and PCR and pillared 2D IPC-1PI materials were prepared in Li-form and their properties were studied by a combination of experimental and theoretical methods. Qualitatively different conclusions are drawn for Li+ located at the channel-wall sites and at the intersection sites (Li+ located at the intersection of two zeolite channels): the Lewis acid strength of Li+ at intersection sites is larger than that at channel-wall sites. The Lewis acid strength of Li+ at channel-wall sites increases with decreasing channel size. When intersecting channels are small (10R 8R in PCR) the intersection Li+ sites are no longer stable and Li+ is preferentially located at the channel-wall sites. Last but not least, the increase in adsorption heats with the decreasing channel size (due to enlarged dispersion contribution) is clearly demonstrated.

Název v anglickém jazyce

The effect of the zeolite pore size on the Lewis acid strength of extra-framework cations

Popis výsledku anglicky

The catalytic activity and the adsorption properties of zeolites depend on their topology and composition. For a better understanding of the structure–activity relationship it is advantageous to focus just on one of these parameters. Zeolites synthesized recently by the ADOR protocol offer a new possibility to investigate the effect of the channel diameter on the adsorption and catalytic properties of zeolites: UTL, OKO, and PCR zeolites consist of the same dense 2D layers (IPC-1P) that are connected with different linkers (D4R, S4R, O-atom, respectively) resulting in the channel systems of different sizes (14R 12R, 12R 10R, 10R 8R, respectively). Consequently, extra-framework cation sites compensating charge of framework Al located in these dense 2D layers (channel-wall sites) are the same in all three zeolites. Therefore, the effect of the zeolite channel size on the Lewis properties of the cationic sites can be investigated independent of other factors determining the quality of Lewis sites. UTL, OKO, and PCR and pillared 2D IPC-1PI materials were prepared in Li-form and their properties were studied by a combination of experimental and theoretical methods. Qualitatively different conclusions are drawn for Li+ located at the channel-wall sites and at the intersection sites (Li+ located at the intersection of two zeolite channels): the Lewis acid strength of Li+ at intersection sites is larger than that at channel-wall sites. The Lewis acid strength of Li+ at channel-wall sites increases with decreasing channel size. When intersecting channels are small (10R 8R in PCR) the intersection Li+ sites are no longer stable and Li+ is preferentially located at the channel-wall sites. Last but not least, the increase in adsorption heats with the decreasing channel size (due to enlarged dispersion contribution) is clearly demonstrated.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CF - Fyzikální chemie a teoretická chemie

OECD FORD obor

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Projekt

<a href="/cs/project/GBP106%2F12%2FG015" target="_blank" >GBP106/12/G015: Vývoj nových nanoporézních adsorbentů a katalyzátorů</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

—

Svazek periodika

18

Číslo periodika v rámci svazku

JUN 2016

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

18063-18073

Kód UT WoS článku

000379486200035

EID výsledku v databázi Scopus

2-s2.0-84978153204