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Catalytic esterification of benzyl alcohol with acetic acid by zirconia-loaded on mesoporous material

Jazi, Mehdi Erfani (2010) Catalytic esterification of benzyl alcohol with acetic acid by zirconia-loaded on mesoporous material. Masters thesis, Universiti Teknologi Malaysia, Faculty of Science.



This research focuses on the synthesis and characterization of metalcontaining mesoporous silica for catalytic esterification of benzyl alcohol with acetic acid. In this study Zr-containing MCM-41 (Zr-MCM-41) with different molar ratios were synthesized successfully, and the influence of the Si/Zr molar ratio on the crystalline structure, textural properties, morphological features and surface acidity of Zr-MCM-41 mesoporous molecular sieves was investigated by X-ray diffraction (XRD), N2 adsorption-desorption measurement, SEM and FTIR (Fourier transform infrared) Spectroscopy, UV-Vis diffuse reflectance (UV-Vis DR), spectroscopy and single point BET. It is observed that the structural ordering of Zr-MCM-41 varies with the Si/Zr ratio, and highly ordered mesoporous molecular sieves could be earned for a Si/Zr molar ratio larger than 5. Calcination may significantly improve the structural regularity. After impregnation with 15 wt % of H3PW12O40 (denoted as HWP hereafter),in esterification reaction of benzyl alcohol with acetic acid, the benzyl alcohol conversion over all the HPW/Zr-MCM-41catalysts linearly increases with increasing the reaction temperature, and selectivity to benzyl acetate was 100 %. The molar ratios of reactants also were investigated for final product yield; the molar ratio of acetic acid to benzyl alcohol can be 2:1 for high yield. The presence of zirconium in tetrahedral coordination was indicated by UV-Vis DR spectra, which shows an absorption band around 220 nm in Zr-MCM41. The catalyst had more active sites than pure Si-MCM-41 due to enhanced hydrophobicity properties and the presence of framework zirconium species as Lewis active sites. Kinetics studies have shown that the esterification reaction follows the Eley-Ridel mechanism. The energy of activation for the reaction follows the order: HPW/Zr-MCM-41(Si/Zr=5) > Zr- MCM-41(Si/Zr=10) > Zr-MCM-41(Si/Zr=20).

Item Type:Thesis (Masters)
Additional Information:Thesis (Sarjana Sains (Kimia)) - Universiti Teknologi Malaysia, 2010; Supervisor : Prof. Dr. Salasiah Endud
Uncontrolled Keywords:catalytic, zirconia, mesoporous material
Subjects:Q Science > QD Chemistry
ID Code:11353
Deposited By: Zalinda Shuratman
Deposited On:13 Dec 2010 01:58
Last Modified:29 Oct 2017 03:49

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