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The Synthesis of Functionalized-Silica/Carbon Catalysts from Rice Husk for The Conversion of Hexose Sugar into Methyl Levulinate and 5-hydroxymethylfurfural

Recently, silica/carbon composite material has received much attention in heterogeneous catalysis due to its unique hybrid properties. However, the difficulties in designing green synthetic methods remain challenging. In this study, varied proportion of silica/carbon heterogeneous catalyst was prepa...

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Main Author: Al-Amsyar, Syed Muhammad
Format: UMK Etheses
Language:English
Published: 2018
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QD Chemistry
Online Access:http://discol.umk.edu.my/id/eprint/8628/1/Final%20Thesis%202.pdf
http://discol.umk.edu.my/id/eprint/8628/
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spelling my.umk.eprints.86282022-08-17T09:04:32Z http://discol.umk.edu.my/id/eprint/8628/ The Synthesis of Functionalized-Silica/Carbon Catalysts from Rice Husk for The Conversion of Hexose Sugar into Methyl Levulinate and 5-hydroxymethylfurfural Al-Amsyar, Syed Muhammad QD Chemistry Recently, silica/carbon composite material has received much attention in heterogeneous catalysis due to its unique hybrid properties. However, the difficulties in designing green synthetic methods remain challenging. In this study, varied proportion of silica/carbon heterogeneous catalyst was prepared directly from rice husk by varying the carbonization temperatures (250, 300, 350, 400, and 450 °C). The prepared composites were functionalized separately with sulfonic acid and aluminium oxide giving the following catalysts: sulfonated-silica/carbon (SO3H-SiO2/C-250, SO3H-SiO2/C-300, SO3H-SiO2/C-350, SO3H-SiO2/C-400, SO3H-SiO2/C-450) and silica/carbon-supported aluminium oxide (Al-SiO2/C-350, Al-SiO2/C-400, and Al-SiO2/C-450). For the SO3H-SiO2/C catalysts, the XRD data confirms these composites were amorphous. Higher carbonization temperature showed an increase in porosity (pore size increased from 40 to 53 Å), total pore volume (increased from 0.031 to 0.288 cm3/g), and surface area (increased from 39 to 260 m2/g) of the composites. EDX analysis showed the silicon-to-carbon weight ratios of the composite increased from 0.114to 1.12 with increase in carbonization temperature. However, the sulfur-to-carbon weight ratio showed a decrease from 0.040 to 0.0055. In the case of Al-SiO2/C catalyst, XPS data showed the presence of aluminium in the form of Al2O3 (1.03 wt%). The XRD data confirms this catalyst was amorphous. N2 adsorption-desorption analysis shows no major impact on textural properties after Al2O3 grafting, as the surface area just decreased from 179 to 141 m2/g. The total pore volume decreased from 0.155 to 0.124 cm3/g, and the pore width increased from 44 to 48 Å. The SO3H-SiO2/C catalysts were used as heterogeneous Brønsted acid catalyst in the conversion of fructose into methyl levulinate (ML) and 5-hydroxymethylfurfural (HMF). A product yield of 90% of ML was obtained at 165 °C in 7 hours in methanol solvent. The yield decreased in the recycling experiments due to continued carbonaceous deposition resulting in deactivation. These composites were also able to convert fructose to HMF in 56 – 74% yield in dimethyl sulfoxide (DMSO) solvent at 130 °C in 5 hours. For the Al-SiO2/C composite, it was used as a bifunctional heterogeneous Lewis-Brønsted acid catalyst to convert glucose into HMF. The use of the catalyst resulted in 52% yield of HMF at 170 °C in 5 hours in N-methylpyrrolidone (NMP) solvent. This catalyst was stable without significant loss of yield after several recycling experiments. 2018 UMK Etheses NonPeerReviewed text en http://discol.umk.edu.my/id/eprint/8628/1/Final%20Thesis%202.pdf Al-Amsyar, Syed Muhammad (2018) The Synthesis of Functionalized-Silica/Carbon Catalysts from Rice Husk for The Conversion of Hexose Sugar into Methyl Levulinate and 5-hydroxymethylfurfural. Doctoral thesis, Universiti Sains Malaysia.
institution Universiti Malaysia Kelantan
building Perpustakaan Universiti Malaysia Kelantan
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaysia Kelantan
content_source UMK Institutional Repository
url_provider http://umkeprints.umk.edu.my/
language English
topic QD Chemistry
spellingShingle QD Chemistry
Al-Amsyar, Syed Muhammad
The Synthesis of Functionalized-Silica/Carbon Catalysts from Rice Husk for The Conversion of Hexose Sugar into Methyl Levulinate and 5-hydroxymethylfurfural
description Recently, silica/carbon composite material has received much attention in heterogeneous catalysis due to its unique hybrid properties. However, the difficulties in designing green synthetic methods remain challenging. In this study, varied proportion of silica/carbon heterogeneous catalyst was prepared directly from rice husk by varying the carbonization temperatures (250, 300, 350, 400, and 450 °C). The prepared composites were functionalized separately with sulfonic acid and aluminium oxide giving the following catalysts: sulfonated-silica/carbon (SO3H-SiO2/C-250, SO3H-SiO2/C-300, SO3H-SiO2/C-350, SO3H-SiO2/C-400, SO3H-SiO2/C-450) and silica/carbon-supported aluminium oxide (Al-SiO2/C-350, Al-SiO2/C-400, and Al-SiO2/C-450). For the SO3H-SiO2/C catalysts, the XRD data confirms these composites were amorphous. Higher carbonization temperature showed an increase in porosity (pore size increased from 40 to 53 Å), total pore volume (increased from 0.031 to 0.288 cm3/g), and surface area (increased from 39 to 260 m2/g) of the composites. EDX analysis showed the silicon-to-carbon weight ratios of the composite increased from 0.114to 1.12 with increase in carbonization temperature. However, the sulfur-to-carbon weight ratio showed a decrease from 0.040 to 0.0055. In the case of Al-SiO2/C catalyst, XPS data showed the presence of aluminium in the form of Al2O3 (1.03 wt%). The XRD data confirms this catalyst was amorphous. N2 adsorption-desorption analysis shows no major impact on textural properties after Al2O3 grafting, as the surface area just decreased from 179 to 141 m2/g. The total pore volume decreased from 0.155 to 0.124 cm3/g, and the pore width increased from 44 to 48 Å. The SO3H-SiO2/C catalysts were used as heterogeneous Brønsted acid catalyst in the conversion of fructose into methyl levulinate (ML) and 5-hydroxymethylfurfural (HMF). A product yield of 90% of ML was obtained at 165 °C in 7 hours in methanol solvent. The yield decreased in the recycling experiments due to continued carbonaceous deposition resulting in deactivation. These composites were also able to convert fructose to HMF in 56 – 74% yield in dimethyl sulfoxide (DMSO) solvent at 130 °C in 5 hours. For the Al-SiO2/C composite, it was used as a bifunctional heterogeneous Lewis-Brønsted acid catalyst to convert glucose into HMF. The use of the catalyst resulted in 52% yield of HMF at 170 °C in 5 hours in N-methylpyrrolidone (NMP) solvent. This catalyst was stable without significant loss of yield after several recycling experiments.
format UMK Etheses
author Al-Amsyar, Syed Muhammad
author_facet Al-Amsyar, Syed Muhammad
author_sort Al-Amsyar, Syed Muhammad
title The Synthesis of Functionalized-Silica/Carbon Catalysts from Rice Husk for The Conversion of Hexose Sugar into Methyl Levulinate and 5-hydroxymethylfurfural
title_short The Synthesis of Functionalized-Silica/Carbon Catalysts from Rice Husk for The Conversion of Hexose Sugar into Methyl Levulinate and 5-hydroxymethylfurfural
title_full The Synthesis of Functionalized-Silica/Carbon Catalysts from Rice Husk for The Conversion of Hexose Sugar into Methyl Levulinate and 5-hydroxymethylfurfural
title_fullStr The Synthesis of Functionalized-Silica/Carbon Catalysts from Rice Husk for The Conversion of Hexose Sugar into Methyl Levulinate and 5-hydroxymethylfurfural
title_full_unstemmed The Synthesis of Functionalized-Silica/Carbon Catalysts from Rice Husk for The Conversion of Hexose Sugar into Methyl Levulinate and 5-hydroxymethylfurfural
title_sort synthesis of functionalized-silica/carbon catalysts from rice husk for the conversion of hexose sugar into methyl levulinate and 5-hydroxymethylfurfural
publishDate 2018
url http://discol.umk.edu.my/id/eprint/8628/1/Final%20Thesis%202.pdf
http://discol.umk.edu.my/id/eprint/8628/
_version_ 1763304011494064128
score 13.211869

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