Reconstructed Mg-Al hydrotalcites prepared by using different rehydration and drying time: Physico-chemical properties and catalytic performance in aldol condensation

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22320%2F17%3A43913297" target="_blank" >RIV/60461373:22320/17:43913297 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/62243136:_____/17:N0000003 RIV/60461373:22350/17:43913297

Výsledek na webu

<a href="http://www.sciencedirect.com.ezproxy.vscht.cz/science/article/pii/S0926860X17300856?via%3Dihub" target="_blank" >http://www.sciencedirect.com.ezproxy.vscht.cz/science/article/pii/S0926860X17300856?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.apcata.2017.02.020" target="_blank" >10.1016/j.apcata.2017.02.020</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Reconstructed Mg-Al hydrotalcites prepared by using different rehydration and drying time: Physico-chemical properties and catalytic performance in aldol condensation

Popis výsledku v původním jazyce

Aldol condensation in presence of reconstructed hydrotalcites as basic catalysts is well documented and attracts an increased attention because it allows producing complex molecules starting from relatively simpler ones. Nevertheless, more studies are necessary for the better understanding of preparation factors that affect the physico-chemical properties of these materials and their catalytic performance. This work considers the effect of the duration of the liquid-phase rehydration of Mg-Al mixed oxide as well as the drying duration of prepared samples on their physico-chemical properties and performance in aldol condensation of furfural and acetone. The properties of all materials were investigated by XRD, TGA, TGA-MS, SEM and DRIFT. Experiments on aldol condensation of furfural and acetone were performed by using a stirred batch reactor at T = 25 °C with Ac:F = 5 molar ratio. The characterization of the prepared materials showed that the recovery of HTC structure occurred within a few seconds of the contact between Mg-Al mixed oxide with liquid water. The content of functional species in all reconstituted HTCs was nearly constant and independent on preparation conditions while the amount of physisorbed water in the prepared samples decreased with increasing drying time. The calcination of as-prepared HTC followed by the subsequent rehydration of Mg-Al mixed oxide resulted in the replacement of &gt;90% carbonate groups on hydroxyls which are Br?nsted basic sites. Consequently, the activity of the reconstructed HTCs in aldol condensation of furfural and acetone was significantly higher compared to Mg-Al mixed oxide. The catalytic performance of rehydrated materials was almost independent on rehydration time while furfural conversion decreased if carrying out the reaction in an aqueous medium with increased water content. On the other hand, properly dried reconstructed HTC with the absence of physisorbed water also exhibited a very low activity in the reaction.

Název v anglickém jazyce

Reconstructed Mg-Al hydrotalcites prepared by using different rehydration and drying time: Physico-chemical properties and catalytic performance in aldol condensation

Popis výsledku anglicky

Aldol condensation in presence of reconstructed hydrotalcites as basic catalysts is well documented and attracts an increased attention because it allows producing complex molecules starting from relatively simpler ones. Nevertheless, more studies are necessary for the better understanding of preparation factors that affect the physico-chemical properties of these materials and their catalytic performance. This work considers the effect of the duration of the liquid-phase rehydration of Mg-Al mixed oxide as well as the drying duration of prepared samples on their physico-chemical properties and performance in aldol condensation of furfural and acetone. The properties of all materials were investigated by XRD, TGA, TGA-MS, SEM and DRIFT. Experiments on aldol condensation of furfural and acetone were performed by using a stirred batch reactor at T = 25 °C with Ac:F = 5 molar ratio. The characterization of the prepared materials showed that the recovery of HTC structure occurred within a few seconds of the contact between Mg-Al mixed oxide with liquid water. The content of functional species in all reconstituted HTCs was nearly constant and independent on preparation conditions while the amount of physisorbed water in the prepared samples decreased with increasing drying time. The calcination of as-prepared HTC followed by the subsequent rehydration of Mg-Al mixed oxide resulted in the replacement of &gt;90% carbonate groups on hydroxyls which are Br?nsted basic sites. Consequently, the activity of the reconstructed HTCs in aldol condensation of furfural and acetone was significantly higher compared to Mg-Al mixed oxide. The catalytic performance of rehydrated materials was almost independent on rehydration time while furfural conversion decreased if carrying out the reaction in an aqueous medium with increased water content. On the other hand, properly dried reconstructed HTC with the absence of physisorbed water also exhibited a very low activity in the reaction.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GA15-21817S" target="_blank" >GA15-21817S: Analýza vztahu mezi strukturou/basicitou Mg/Al, Ca/Al a Zn/Al směsných oxidů a jejich aktivitou v aldol kondenzaci a transesterifikaci</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

APPLIED CATALYSIS A-GENERAL

ISSN

0926-860X

e-ISSN

—

Svazek periodika

536

Číslo periodika v rámci svazku

APR 25 2017

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

85-96

Kód UT WoS článku

000398647200010

EID výsledku v databázi Scopus

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