Synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate

Sodalite is a type of zeolite having ultramicropore size and high thermal stability with strong basic property. However, microporous sodalite has several drawbacks in the catalyst application due to its small pore size (2.8 Å) and low surface area. To overcome these disadvantages microporous sodalit...

Full description

Saved in:

Bibliographic Details
Main Author:	Lapari, Shima Shirani
Format:	Thesis
Language:	English
Published:	2016
Subjects:	QD Chemistry
Online Access:	http://eprints.utm.my/id/eprint/81668/1/ShimaShiraniLapariPFS2016.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-utm-ep.81668
record_format	uketd_dc
spelling	my-utm-ep.816682019-09-10T01:53:29Z Synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate 2016 Lapari, Shima Shirani QD Chemistry Sodalite is a type of zeolite having ultramicropore size and high thermal stability with strong basic property. However, microporous sodalite has several drawbacks in the catalyst application due to its small pore size (2.8 Å) and low surface area. To overcome these disadvantages microporous sodalite was modified to have mesoporous structure, while still maintaining its active sites suitable for catalyst applications. In this study, mesoporous sodalite was synthesized using various organic templates as structure directing molecules and used as a base catalyst in the Knoevenagel condensation reaction. A hierarchical mesoporous sodalite has been synthesized hydrothermally at 150ºC for crystallization using various mesotemplates. Results from XRD and FTIR spectroscopy showed that all templates being used in the synthesis produced sodalite phase. The sodalite synthesized using organosilane template and a dual template containing a mixture of tetrapropylammonium hydroxide and cetyltrimethylammonium bromide, have shown mesoporosity, as proven by nitrogen adsorption analysis. The field emission scanning electron microscopy (FESEM) micrographs of the mesoporous sodalite obtained showed spherical morphology in the size range ~ 10-16 nm. 29Si magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy showed the sodalite framework has a Si/Al ratio equal to 1, while 27Al MAS NMR spectrum exhibited the unsymmetrical tetrahedral Al. The synthesized sodalite samples which were modified with metal ions (K+, Cs+) enhanced the sodalite basicity. Results from Hammet indicators and temperature programmed desorption of CO2 studies revealed that potassium mesoporous sodalite prepared using dual template has the highest strength and amount of basic sites. The reactivity for all of the prepared sodalite samples was evaluated in the Knoevenagel condensation of 2-nitrobenzaldehyde and ethyl acetoacetate, producing 4-(2-nitrophenyl)-but-3-en-2-one as the main product, and trans-2-nitrocinnamic acid as the side product. All synthesized mesoporous sodalites were more reactive than the microporous sodalites counterpart, producing > 70% selectivity for the main product. Based on the conversion of reactant, the potassium mesoporous sodalite using dual template has shown the most active catalyst which gave 95% conversion at 150oC and 6 hours reaction using 0.2 g catalyst. Result from the experimental study was in accordance with the response surface methodology (RSM) findings for the optimum reaction parameters which were at 150oC, 6 hours reaction time, 0.2 g catalyst for 97.1% conversion. This study has proven that besides basicity, hierarchical mesoporosity of sodalite is important for the enhancement of the reactivity of the sodalite catalyst for reactions involving larger molecules such as in the Knoevenagel reaction. 2016 Thesis http://eprints.utm.my/id/eprint/81668/ http://eprints.utm.my/id/eprint/81668/1/ShimaShiraniLapariPFS2016.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:125992 phd doctoral Universiti Teknologi Malaysia Chemistry
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	QD Chemistry
spellingShingle	QD Chemistry Lapari, Shima Shirani Synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate
description	Sodalite is a type of zeolite having ultramicropore size and high thermal stability with strong basic property. However, microporous sodalite has several drawbacks in the catalyst application due to its small pore size (2.8 Å) and low surface area. To overcome these disadvantages microporous sodalite was modified to have mesoporous structure, while still maintaining its active sites suitable for catalyst applications. In this study, mesoporous sodalite was synthesized using various organic templates as structure directing molecules and used as a base catalyst in the Knoevenagel condensation reaction. A hierarchical mesoporous sodalite has been synthesized hydrothermally at 150ºC for crystallization using various mesotemplates. Results from XRD and FTIR spectroscopy showed that all templates being used in the synthesis produced sodalite phase. The sodalite synthesized using organosilane template and a dual template containing a mixture of tetrapropylammonium hydroxide and cetyltrimethylammonium bromide, have shown mesoporosity, as proven by nitrogen adsorption analysis. The field emission scanning electron microscopy (FESEM) micrographs of the mesoporous sodalite obtained showed spherical morphology in the size range ~ 10-16 nm. 29Si magic-angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy showed the sodalite framework has a Si/Al ratio equal to 1, while 27Al MAS NMR spectrum exhibited the unsymmetrical tetrahedral Al. The synthesized sodalite samples which were modified with metal ions (K+, Cs+) enhanced the sodalite basicity. Results from Hammet indicators and temperature programmed desorption of CO2 studies revealed that potassium mesoporous sodalite prepared using dual template has the highest strength and amount of basic sites. The reactivity for all of the prepared sodalite samples was evaluated in the Knoevenagel condensation of 2-nitrobenzaldehyde and ethyl acetoacetate, producing 4-(2-nitrophenyl)-but-3-en-2-one as the main product, and trans-2-nitrocinnamic acid as the side product. All synthesized mesoporous sodalites were more reactive than the microporous sodalites counterpart, producing > 70% selectivity for the main product. Based on the conversion of reactant, the potassium mesoporous sodalite using dual template has shown the most active catalyst which gave 95% conversion at 150oC and 6 hours reaction using 0.2 g catalyst. Result from the experimental study was in accordance with the response surface methodology (RSM) findings for the optimum reaction parameters which were at 150oC, 6 hours reaction time, 0.2 g catalyst for 97.1% conversion. This study has proven that besides basicity, hierarchical mesoporosity of sodalite is important for the enhancement of the reactivity of the sodalite catalyst for reactions involving larger molecules such as in the Knoevenagel reaction.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Lapari, Shima Shirani
author_facet	Lapari, Shima Shirani
author_sort	Lapari, Shima Shirani
title	Synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate
title_short	Synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate
title_full	Synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate
title_fullStr	Synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate
title_full_unstemmed	Synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate
title_sort	synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate
granting_institution	Universiti Teknologi Malaysia
granting_department	Chemistry
publishDate	2016
url	http://eprints.utm.my/id/eprint/81668/1/ShimaShiraniLapariPFS2016.pdf
_version_	1747818384801660928

Synthesis of mesoporous sodalite using various organic templates as catalyst in knoevenagel condensation reaction of 2-nitrobenzaldehyde and ethyl acetoacetate

Similar Items