Controlling the competitive growth of zeolite phases without using an organic structure-directing agent. Synthesis of Al-rich *BEA

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F22%3A00554273" target="_blank" >RIV/61388955:_____/22:00554273 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216275:25310/22:39919061

Výsledek na webu

<a href="http://hdl.handle.net/11104/0328904" target="_blank" >http://hdl.handle.net/11104/0328904</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.micromeso.2022.111726" target="_blank" >10.1016/j.micromeso.2022.111726</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Controlling the competitive growth of zeolite phases without using an organic structure-directing agent. Synthesis of Al-rich *BEA

Popis výsledku v původním jazyce

The synthesis of zeolites without using an organic structure-directing agent (OSDA) offers great environmental and economic advantages. However, the zeolites being formed are not stabilized by the organic molecules and kinetic control of the synthesis ensuring high yield and purity of the phases is challenging for many zeolites. For OSDA-free synthesis of an Al-rich *BEA zeolite, this study shows that the zeolite is formed as a metastable phase that can undergo transformation immediately after completion of its crystallization to form a thermodynamically more stable MOR zeolite according to Ostwald's rule of stages. The OSDA-free zeolite synthesis is a dynamic process in which crystallization and dissolution occur simultaneously. As soon as a thermodynamically more stable MOR zeolite begins to form in the synthesis mixture, its formation causes depletion of the Al and Si from the synthesis mixture, and, because of the desaturation of the synthesis gel, the original *BEA zeolite begins to dissolve rapidly under hydrothermal conditions. The formation of targeted and parasitic zeolite structures is fundamentally affected by the Al and Si sources. Sources of Al and Si with suitable solubility and the presence of stable zeolite *BEA seeds allow kinetic control to direct the exclusive formation of *BEA zeolite up to a relatively high yields. Then, however, the MOR zeolite phase appears in the product and its formation becomes predominant. This study demonstrates the crucial importance of kinetic control for the selective formation of metastable zeolites in the OSDA-free synthesis.

Název v anglickém jazyce

Controlling the competitive growth of zeolite phases without using an organic structure-directing agent. Synthesis of Al-rich *BEA

Popis výsledku anglicky

The synthesis of zeolites without using an organic structure-directing agent (OSDA) offers great environmental and economic advantages. However, the zeolites being formed are not stabilized by the organic molecules and kinetic control of the synthesis ensuring high yield and purity of the phases is challenging for many zeolites. For OSDA-free synthesis of an Al-rich *BEA zeolite, this study shows that the zeolite is formed as a metastable phase that can undergo transformation immediately after completion of its crystallization to form a thermodynamically more stable MOR zeolite according to Ostwald's rule of stages. The OSDA-free zeolite synthesis is a dynamic process in which crystallization and dissolution occur simultaneously. As soon as a thermodynamically more stable MOR zeolite begins to form in the synthesis mixture, its formation causes depletion of the Al and Si from the synthesis mixture, and, because of the desaturation of the synthesis gel, the original *BEA zeolite begins to dissolve rapidly under hydrothermal conditions. The formation of targeted and parasitic zeolite structures is fundamentally affected by the Al and Si sources. Sources of Al and Si with suitable solubility and the presence of stable zeolite *BEA seeds allow kinetic control to direct the exclusive formation of *BEA zeolite up to a relatively high yields. Then, however, the MOR zeolite phase appears in the product and its formation becomes predominant. This study demonstrates the crucial importance of kinetic control for the selective formation of metastable zeolites in the OSDA-free synthesis.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

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

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Microporous and Mesoporous Materials

ISSN

1387-1811

e-ISSN

1873-3093

Svazek periodika

333

Číslo periodika v rámci svazku

MAR 2022

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

9

Strana od-do

111726

Kód UT WoS článku

000761870500001

EID výsledku v databázi Scopus

2-s2.0-85123897179