Synthesis of Vanadium Antimony Oxide Catalysts Via Slurry, Sol-Gel and Solid-State Methods

The influence of synthesis method on the formation of VSbO catalysts was examined. The syntheses applied in the present work were slurry, sol-gel and solid-state reaction method. The precursors obtained were further heated at various calcinations temperature; 673, 773 and 873 K and the dependence of...

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Main Author:	Razali, Mohd Asri
Format:	Thesis
Language:	English English
Published:	2004
Subjects:	Vanadium oxide
Online Access:	http://psasir.upm.edu.my/id/eprint/574/1/549666_FS_2004_1.pdf
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id	my-upm-ir.574
record_format	uketd_dc
spelling	my-upm-ir.5742013-05-27T06:49:24Z Synthesis of Vanadium Antimony Oxide Catalysts Via Slurry, Sol-Gel and Solid-State Methods 2004-12 Razali, Mohd Asri The influence of synthesis method on the formation of VSbO catalysts was examined. The syntheses applied in the present work were slurry, sol-gel and solid-state reaction method. The precursors obtained were further heated at various calcinations temperature; 673, 773 and 873 K and the dependence of the physicochemical characteristics of all the samples on the heat treatment imposed were also investigated. The synthesis conditions for the preparation of crystalline vanadium antimony oxide as mixed phases were found. Nitrogen physisorption at 77 K revealed samples prepared by slurry method gave higher Brunauer-Emmet-Teller (BET) surface area, SBET values compared to samples prepared by sol-gel and solid-state reaction methods. This was due to the chemical procedures done on the sample which promotes the formation of non-uniform particles with slit shaped particles compared to uniform particles formation displayed by other two methods. This phenomenon can be observed in Scanning Electron Microscopic, SEM micrograph. Upon heat treatment, SBET value decreased for all samples prepared by different method due to sintering effect. Nevertheless, the molar fractions of VSbO4 and -Sb2O4 phases depended on the heating temperature. As has been evidenced in X-ray Diffraction (XRD) analysis and Fourier Transform Infrared (FTIR) spectroscopy, higher calcination temperatures promote the formation of these two phases. The existence of the two phases which became dominant as the heating temperatures were gradually increased, are in accordance with reduced activities. Combination of transient kinetic studies; O2-Temperature Programmed Desorption, H2-Temperature Programmed Reduction and Temperature Programmed Reaction of propane, revealed the dependence of reducibility and catalyst activity with the relative intensity of VSbO4 rutile and -Sb2O4 phases. The VSbO samples were found to be increased in reduced activity as calcination temperature is increased. Temperature programmed reaction analysis suggested that the transformation of propane to acrylic acid are through the formation of intermediates propene and acrolein. Vanadium oxide 2004-12 Thesis http://psasir.upm.edu.my/id/eprint/574/ http://psasir.upm.edu.my/id/eprint/574/1/549666_FS_2004_1.pdf application/pdf en public masters Universiti Putra Malaysia Vanadium oxide Faculty of Science English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
topic	Vanadium oxide
spellingShingle	Vanadium oxide Razali, Mohd Asri Synthesis of Vanadium Antimony Oxide Catalysts Via Slurry, Sol-Gel and Solid-State Methods
description	The influence of synthesis method on the formation of VSbO catalysts was examined. The syntheses applied in the present work were slurry, sol-gel and solid-state reaction method. The precursors obtained were further heated at various calcinations temperature; 673, 773 and 873 K and the dependence of the physicochemical characteristics of all the samples on the heat treatment imposed were also investigated. The synthesis conditions for the preparation of crystalline vanadium antimony oxide as mixed phases were found. Nitrogen physisorption at 77 K revealed samples prepared by slurry method gave higher Brunauer-Emmet-Teller (BET) surface area, SBET values compared to samples prepared by sol-gel and solid-state reaction methods. This was due to the chemical procedures done on the sample which promotes the formation of non-uniform particles with slit shaped particles compared to uniform particles formation displayed by other two methods. This phenomenon can be observed in Scanning Electron Microscopic, SEM micrograph. Upon heat treatment, SBET value decreased for all samples prepared by different method due to sintering effect. Nevertheless, the molar fractions of VSbO4 and -Sb2O4 phases depended on the heating temperature. As has been evidenced in X-ray Diffraction (XRD) analysis and Fourier Transform Infrared (FTIR) spectroscopy, higher calcination temperatures promote the formation of these two phases. The existence of the two phases which became dominant as the heating temperatures were gradually increased, are in accordance with reduced activities. Combination of transient kinetic studies; O2-Temperature Programmed Desorption, H2-Temperature Programmed Reduction and Temperature Programmed Reaction of propane, revealed the dependence of reducibility and catalyst activity with the relative intensity of VSbO4 rutile and -Sb2O4 phases. The VSbO samples were found to be increased in reduced activity as calcination temperature is increased. Temperature programmed reaction analysis suggested that the transformation of propane to acrylic acid are through the formation of intermediates propene and acrolein.
format	Thesis
qualification_level	Master's degree
author	Razali, Mohd Asri
author_facet	Razali, Mohd Asri
author_sort	Razali, Mohd Asri
title	Synthesis of Vanadium Antimony Oxide Catalysts Via Slurry, Sol-Gel and Solid-State Methods
title_short	Synthesis of Vanadium Antimony Oxide Catalysts Via Slurry, Sol-Gel and Solid-State Methods
title_full	Synthesis of Vanadium Antimony Oxide Catalysts Via Slurry, Sol-Gel and Solid-State Methods
title_fullStr	Synthesis of Vanadium Antimony Oxide Catalysts Via Slurry, Sol-Gel and Solid-State Methods
title_full_unstemmed	Synthesis of Vanadium Antimony Oxide Catalysts Via Slurry, Sol-Gel and Solid-State Methods
title_sort	synthesis of vanadium antimony oxide catalysts via slurry, sol-gel and solid-state methods
granting_institution	Universiti Putra Malaysia
granting_department	Faculty of Science
publishDate	2004
url	http://psasir.upm.edu.my/id/eprint/574/1/549666_FS_2004_1.pdf
_version_	1747810252349243392

Synthesis of Vanadium Antimony Oxide Catalysts Via Slurry, Sol-Gel and Solid-State Methods

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