Study On Copper Incorporated Mesoporous Silica SBA-15 For N2O Catalytic Decomposition

Nitrous oxide (N2O) is an environmental pollutant because it is a relatively strong greenhouse effect gas and contributes towards the destruction of ozone in the stratosphere. Direct decomposition of N2O by catalysts represents one of the potential solutions to minimize N2O emissions. This research...

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Main Author:	Mohd Husin, Mohd Haizal
Format:	Thesis
Language:	English
Published:	2016
Subjects:	T Technology (General)
Online Access:	http://eprints.utem.edu.my/id/eprint/18864/1/Study%20On%20Copper%20Incorporated%20Mesoporous%20Silica%20SBA-15%20For%20N2O%20Catalytic%20Decomposition%2024%20Pages.pdf
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spelling	my-utem-ep.188642017-07-31T00:59:00Z Study On Copper Incorporated Mesoporous Silica SBA-15 For N2O Catalytic Decomposition 2016 Mohd Husin, Mohd Haizal T Technology (General) TK Electrical engineering. Electronics Nuclear engineering Nitrous oxide (N2O) is an environmental pollutant because it is a relatively strong greenhouse effect gas and contributes towards the destruction of ozone in the stratosphere. Direct decomposition of N2O by catalysts represents one of the potential solutions to minimize N2O emissions. This research focuses on Cu incorporation into SBA-15 mesoporous silica by pH modification method using hexamethylenetetramine (HMTA) as an internal pH-modifier and its potential use as a catalyst for N2O decomposition. The effect of acidity on SBA-15 preparation through different initial HCl concentration and the addition of HMTA as pH modifier were investigated. The SBA-15 formed well-ordered hexagonal mesoporous structure at high acidity (2.0 M) and poor ordered hexagonal pore structure at low acidity condition (0.005 M). It was found that under moderate acidic condition (0.1 M HCl) with addition of HMTA (HMTA:Si molar ratio 1:10), well-ordered hexagonal mesoporous SBA-15 could be produced. Meanwhile, copper was chosen for further studies on metal incorporation of SBA-15 (M/SBA-15) because Cu-containing SBA-15 has the highest catalytic activity for N2O decomposition compared to that of other first row transition metals impregnated on SBA-15. Copper incorporated mesoporous silica (Cu-SBA-15) has been successfully prepared by direct synthesis under medium acidic condition with addition of HMTA as a pH modifier. The Cu/SBA-15 produced were characterised using XRD, N2 adsorption-desorption, TEM, SEM, FTIR, UV-vis, XPS and TPR. The results indicate that Cu was mainly incorporated into the framework of SBA-15. The unit-cell, surface area, pore volume and wall thickness increased after the incorporation of the copper ions in SBA-15. HMTA plays a very important role to increase internal pH in order to introduce copper into the framework of SBA-15 silica. Cu loading on Cu/SBA-15 determined using AAS is almost the same to the initial Cu amount, when the pH value is above isoelectronic of silica (pH=2) due to addition of HMTA. Higher amount of HMTA, however, lead to the destruction of SBA-15 structure. Compared with Cu/SBA-15 impregnation method, Cu/SBA-15 prepared through pH modification method shows much higher activity for N2O catalytic decomposition due to 80% N2O conversion at 550C and reached 100% at 600°C. The activation energy for the reaction catalysed by Cu/SBA-15 prepared through pH modification method is 91.9 – 121.6 kJ/mol. This is much lower compared to that catalysed by Cu/SBA-15 prepared though impregnation, that is in the range between 148.5 – 173.9 kJ/mol. Cu/SBA-15 incorporated sample also has higher activity due catalytic activity started at 300 °C and reaches more 80% conversion at 500°C for catalytic reduction of N2O by CH4. UTeM 2016 Thesis http://eprints.utem.edu.my/id/eprint/18864/ http://eprints.utem.edu.my/id/eprint/18864/1/Study%20On%20Copper%20Incorporated%20Mesoporous%20Silica%20SBA-15%20For%20N2O%20Catalytic%20Decomposition%2024%20Pages.pdf text en public http://library.utem.edu.my:8000/elmu/index.jsp?module=webopac-d&action=fullDisplayRetriever.jsp&szMaterialNo=0000102290 phd doctoral Universiti Teknikal Malaysia Melaka Faculty Of Mechanical Engineering
institution	Universiti Teknikal Malaysia Melaka
collection	UTeM Repository
language	English
topic	T Technology (General) T Technology (General)
spellingShingle	T Technology (General) T Technology (General) Mohd Husin, Mohd Haizal Study On Copper Incorporated Mesoporous Silica SBA-15 For N2O Catalytic Decomposition
description	Nitrous oxide (N2O) is an environmental pollutant because it is a relatively strong greenhouse effect gas and contributes towards the destruction of ozone in the stratosphere. Direct decomposition of N2O by catalysts represents one of the potential solutions to minimize N2O emissions. This research focuses on Cu incorporation into SBA-15 mesoporous silica by pH modification method using hexamethylenetetramine (HMTA) as an internal pH-modifier and its potential use as a catalyst for N2O decomposition. The effect of acidity on SBA-15 preparation through different initial HCl concentration and the addition of HMTA as pH modifier were investigated. The SBA-15 formed well-ordered hexagonal mesoporous structure at high acidity (2.0 M) and poor ordered hexagonal pore structure at low acidity condition (0.005 M). It was found that under moderate acidic condition (0.1 M HCl) with addition of HMTA (HMTA:Si molar ratio 1:10), well-ordered hexagonal mesoporous SBA-15 could be produced. Meanwhile, copper was chosen for further studies on metal incorporation of SBA-15 (M/SBA-15) because Cu-containing SBA-15 has the highest catalytic activity for N2O decomposition compared to that of other first row transition metals impregnated on SBA-15. Copper incorporated mesoporous silica (Cu-SBA-15) has been successfully prepared by direct synthesis under medium acidic condition with addition of HMTA as a pH modifier. The Cu/SBA-15 produced were characterised using XRD, N2 adsorption-desorption, TEM, SEM, FTIR, UV-vis, XPS and TPR. The results indicate that Cu was mainly incorporated into the framework of SBA-15. The unit-cell, surface area, pore volume and wall thickness increased after the incorporation of the copper ions in SBA-15. HMTA plays a very important role to increase internal pH in order to introduce copper into the framework of SBA-15 silica. Cu loading on Cu/SBA-15 determined using AAS is almost the same to the initial Cu amount, when the pH value is above isoelectronic of silica (pH=2) due to addition of HMTA. Higher amount of HMTA, however, lead to the destruction of SBA-15 structure. Compared with Cu/SBA-15 impregnation method, Cu/SBA-15 prepared through pH modification method shows much higher activity for N2O catalytic decomposition due to 80% N2O conversion at 550C and reached 100% at 600°C. The activation energy for the reaction catalysed by Cu/SBA-15 prepared through pH modification method is 91.9 – 121.6 kJ/mol. This is much lower compared to that catalysed by Cu/SBA-15 prepared though impregnation, that is in the range between 148.5 – 173.9 kJ/mol. Cu/SBA-15 incorporated sample also has higher activity due catalytic activity started at 300 °C and reaches more 80% conversion at 500°C for catalytic reduction of N2O by CH4.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Mohd Husin, Mohd Haizal
author_facet	Mohd Husin, Mohd Haizal
author_sort	Mohd Husin, Mohd Haizal
title	Study On Copper Incorporated Mesoporous Silica SBA-15 For N2O Catalytic Decomposition
title_short	Study On Copper Incorporated Mesoporous Silica SBA-15 For N2O Catalytic Decomposition
title_full	Study On Copper Incorporated Mesoporous Silica SBA-15 For N2O Catalytic Decomposition
title_fullStr	Study On Copper Incorporated Mesoporous Silica SBA-15 For N2O Catalytic Decomposition
title_full_unstemmed	Study On Copper Incorporated Mesoporous Silica SBA-15 For N2O Catalytic Decomposition
title_sort	study on copper incorporated mesoporous silica sba-15 for n2o catalytic decomposition
granting_institution	Universiti Teknikal Malaysia Melaka
granting_department	Faculty Of Mechanical Engineering
publishDate	2016
url	http://eprints.utem.edu.my/id/eprint/18864/1/Study%20On%20Copper%20Incorporated%20Mesoporous%20Silica%20SBA-15%20For%20N2O%20Catalytic%20Decomposition%2024%20Pages.pdf
_version_	1747833957078007808

Study On Copper Incorporated Mesoporous Silica SBA-15 For N2O Catalytic Decomposition

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