Synthesis, Characterization and Catalytic Performance of H3SiW12O40/SiO2 Prepared by Sol-Gel Technique

The purpose of this work is to study the synthesis, characterization, and catalytic performance of two types of solid heteropoly acid catalysts, namely, silicotungstic acid bulk (STAB) and STA-silica sol-gel (STA-SG) compared with sulfuric acid. From the XPS analyses, there was a significant formati...

Full description

Bibliographic Details
Main Authors: W. N. R. W. Isahak, M. Ismail, N. M. Nordin, J. M. Jahim, M. A. Yarmo
Format: Article
Language:English
Published: Hindawi Limited 2011-01-01
Series:Journal of Nanotechnology
Online Access:http://dx.doi.org/10.1155/2011/507692
id doaj-7defe591715a4ded8a53f37cb1dabd4b
record_format Article
spelling doaj-7defe591715a4ded8a53f37cb1dabd4b2020-11-24T23:19:35ZengHindawi LimitedJournal of Nanotechnology1687-95031687-95112011-01-01201110.1155/2011/507692507692Synthesis, Characterization and Catalytic Performance of H3SiW12O40/SiO2 Prepared by Sol-Gel TechniqueW. N. R. W. Isahak0M. Ismail1N. M. Nordin2J. M. Jahim3M. A. Yarmo4Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, MalaysiaSchool of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, MalaysiaDepartment of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, MalaysiaSchool of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, MalaysiaDepartment of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 Bangi, MalaysiaThe purpose of this work is to study the synthesis, characterization, and catalytic performance of two types of solid heteropoly acid catalysts, namely, silicotungstic acid bulk (STAB) and STA-silica sol-gel (STA-SG) compared with sulfuric acid. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W, and Si-O-Si bonding in STA-SG compared to that in STAB. The main spectra of O1s (90.74%, 531.5 eV) followed by other O1s peak (9.26%, 532.8 eV) were due to the presence of W-O-W and W-O-Si bonds, respectively. The STA-SG catalyst was found to be the more environmentally benign solid acid catalyst for the esterification reaction between oleic acid and glycerol due to its lower toxicity supported by silica via sol-gel technique. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4 and the STAB gave high conversion of 100% and 98% but at a lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94% but with a significantly higher GME selectivity of 95%, rendering it the more efficient solid acid catalyst.http://dx.doi.org/10.1155/2011/507692
collection DOAJ
language English
format Article
sources DOAJ
author W. N. R. W. Isahak
M. Ismail
N. M. Nordin
J. M. Jahim
M. A. Yarmo
spellingShingle W. N. R. W. Isahak
M. Ismail
N. M. Nordin
J. M. Jahim
M. A. Yarmo
Synthesis, Characterization and Catalytic Performance of H3SiW12O40/SiO2 Prepared by Sol-Gel Technique
Journal of Nanotechnology
author_facet W. N. R. W. Isahak
M. Ismail
N. M. Nordin
J. M. Jahim
M. A. Yarmo
author_sort W. N. R. W. Isahak
title Synthesis, Characterization and Catalytic Performance of H3SiW12O40/SiO2 Prepared by Sol-Gel Technique
title_short Synthesis, Characterization and Catalytic Performance of H3SiW12O40/SiO2 Prepared by Sol-Gel Technique
title_full Synthesis, Characterization and Catalytic Performance of H3SiW12O40/SiO2 Prepared by Sol-Gel Technique
title_fullStr Synthesis, Characterization and Catalytic Performance of H3SiW12O40/SiO2 Prepared by Sol-Gel Technique
title_full_unstemmed Synthesis, Characterization and Catalytic Performance of H3SiW12O40/SiO2 Prepared by Sol-Gel Technique
title_sort synthesis, characterization and catalytic performance of h3siw12o40/sio2 prepared by sol-gel technique
publisher Hindawi Limited
series Journal of Nanotechnology
issn 1687-9503
1687-9511
publishDate 2011-01-01
description The purpose of this work is to study the synthesis, characterization, and catalytic performance of two types of solid heteropoly acid catalysts, namely, silicotungstic acid bulk (STAB) and STA-silica sol-gel (STA-SG) compared with sulfuric acid. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W, and Si-O-Si bonding in STA-SG compared to that in STAB. The main spectra of O1s (90.74%, 531.5 eV) followed by other O1s peak (9.26%, 532.8 eV) were due to the presence of W-O-W and W-O-Si bonds, respectively. The STA-SG catalyst was found to be the more environmentally benign solid acid catalyst for the esterification reaction between oleic acid and glycerol due to its lower toxicity supported by silica via sol-gel technique. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4 and the STAB gave high conversion of 100% and 98% but at a lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94% but with a significantly higher GME selectivity of 95%, rendering it the more efficient solid acid catalyst.
url http://dx.doi.org/10.1155/2011/507692
work_keys_str_mv AT wnrwisahak synthesischaracterizationandcatalyticperformanceofh3siw12o40sio2preparedbysolgeltechnique
AT mismail synthesischaracterizationandcatalyticperformanceofh3siw12o40sio2preparedbysolgeltechnique
AT nmnordin synthesischaracterizationandcatalyticperformanceofh3siw12o40sio2preparedbysolgeltechnique
AT jmjahim synthesischaracterizationandcatalyticperformanceofh3siw12o40sio2preparedbysolgeltechnique
AT mayarmo synthesischaracterizationandcatalyticperformanceofh3siw12o40sio2preparedbysolgeltechnique
_version_ 1725578222291124224