Modification and Characterisation of Vanadium Phosphorus Oxide Catalysts for Selective Oxidation of Propane to Acrylic Acid

Vanadium phosphate catalysts synthesized via VOPO4∙2H2O were further reduced in isobutanol to produce VOHPO4∙0.5H2O precursor. Calcination of this precursor in propane/air environment (1% propane in air) transformed into activated (VO)2P2O7 catalysts. The morphology, structure, oxidant’s nature and...

Full description

Saved in:

Bibliographic Details
Main Author:	Saw, Chaing Shen
Format:	Thesis
Language:	English English
Published:	2006
Subjects:	Vanadium catalysts Propane - Oxidation Acrylic acid
Online Access:	http://psasir.upm.edu.my/id/eprint/564/1/FS_2006_30.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-upm-ir.564
record_format	uketd_dc
spelling	my-upm-ir.5642013-05-27T06:49:19Z Modification and Characterisation of Vanadium Phosphorus Oxide Catalysts for Selective Oxidation of Propane to Acrylic Acid 2006-02 Saw, Chaing Shen Vanadium phosphate catalysts synthesized via VOPO4∙2H2O were further reduced in isobutanol to produce VOHPO4∙0.5H2O precursor. Calcination of this precursor in propane/air environment (1% propane in air) transformed into activated (VO)2P2O7 catalysts. The morphology, structure, oxidant’s nature and catalytic performance for propane oxidation to acrylic acid over this catalyst strongly depended on the duration of calcination. The catalyst calcined for 36 h (VPD36P) exhibits low surface area. However, prolonged calcination promoted a higher surface area with better crystallization. VIII and VV phases are detected in all catalysts. The SEM micrographs showed that all propane/air catalysts gave rosebud type agglomerates with various sizes but in a uniform shape. A comparison of effect of calcinations environments on the vanadium phosphate catalyst in flow of both propane/air and butane/air, the latter calcinations environment produced catalyst with more platelet and higher surface area. Chemical analysis also shows that VPDB catalyst consist of higher amount of VV (26%) and 74% of VIV phase whereas VPDP only contains 76 and 9.8% of VIV and VV phases, respectively. Interestingly, VPDP also showed 14.2% of VIII phase. For n-butane oxidation at 673 K, VPDB gave 83% of conversion and 63% of MA selectivity whereas VPDP gave 75% of conversion and 64% of MA selectivity. The n-butane/air calcined catalyst, VPDB showed better activity (14.1%) in propane oxidation than the propne/air calcined catalyst, VPDP (7.9%). The addition of 1, 2 and 5 mol % of Zr into (VO)2P2O7 catalysts produced a single vanadyl pyrophosphate phase in VOPO4∙2H2O method with different degree of crystallinity. The presence of lower percentage of Zr (1 and 2%) improved the surface area of the catalysts; however, the surface area of the catalyst with 5% of Zr added is decreased. The SEM micrograph for all Zr modified catalysts gave roughed rosebud agglomerates as compared to the unpromoted catalyst. VPDZr1 catalyst was found to be the most selective catalyst among all the Zr doped catalysts in propane oxidation. Vanadium catalysts Propane - Oxidation Acrylic acid 2006-02 Thesis http://psasir.upm.edu.my/id/eprint/564/ http://psasir.upm.edu.my/id/eprint/564/1/FS_2006_30.pdf application/pdf en public masters Universiti Putra Malaysia Vanadium catalysts Propane - Oxidation Acrylic acid Faculty of Science English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
topic	Vanadium catalysts Propane - Oxidation Acrylic acid
spellingShingle	Vanadium catalysts Propane - Oxidation Acrylic acid Saw, Chaing Shen Modification and Characterisation of Vanadium Phosphorus Oxide Catalysts for Selective Oxidation of Propane to Acrylic Acid
description	Vanadium phosphate catalysts synthesized via VOPO4∙2H2O were further reduced in isobutanol to produce VOHPO4∙0.5H2O precursor. Calcination of this precursor in propane/air environment (1% propane in air) transformed into activated (VO)2P2O7 catalysts. The morphology, structure, oxidant’s nature and catalytic performance for propane oxidation to acrylic acid over this catalyst strongly depended on the duration of calcination. The catalyst calcined for 36 h (VPD36P) exhibits low surface area. However, prolonged calcination promoted a higher surface area with better crystallization. VIII and VV phases are detected in all catalysts. The SEM micrographs showed that all propane/air catalysts gave rosebud type agglomerates with various sizes but in a uniform shape. A comparison of effect of calcinations environments on the vanadium phosphate catalyst in flow of both propane/air and butane/air, the latter calcinations environment produced catalyst with more platelet and higher surface area. Chemical analysis also shows that VPDB catalyst consist of higher amount of VV (26%) and 74% of VIV phase whereas VPDP only contains 76 and 9.8% of VIV and VV phases, respectively. Interestingly, VPDP also showed 14.2% of VIII phase. For n-butane oxidation at 673 K, VPDB gave 83% of conversion and 63% of MA selectivity whereas VPDP gave 75% of conversion and 64% of MA selectivity. The n-butane/air calcined catalyst, VPDB showed better activity (14.1%) in propane oxidation than the propne/air calcined catalyst, VPDP (7.9%). The addition of 1, 2 and 5 mol % of Zr into (VO)2P2O7 catalysts produced a single vanadyl pyrophosphate phase in VOPO4∙2H2O method with different degree of crystallinity. The presence of lower percentage of Zr (1 and 2%) improved the surface area of the catalysts; however, the surface area of the catalyst with 5% of Zr added is decreased. The SEM micrograph for all Zr modified catalysts gave roughed rosebud agglomerates as compared to the unpromoted catalyst. VPDZr1 catalyst was found to be the most selective catalyst among all the Zr doped catalysts in propane oxidation.
format	Thesis
qualification_level	Master's degree
author	Saw, Chaing Shen
author_facet	Saw, Chaing Shen
author_sort	Saw, Chaing Shen
title	Modification and Characterisation of Vanadium Phosphorus Oxide Catalysts for Selective Oxidation of Propane to Acrylic Acid
title_short	Modification and Characterisation of Vanadium Phosphorus Oxide Catalysts for Selective Oxidation of Propane to Acrylic Acid
title_full	Modification and Characterisation of Vanadium Phosphorus Oxide Catalysts for Selective Oxidation of Propane to Acrylic Acid
title_fullStr	Modification and Characterisation of Vanadium Phosphorus Oxide Catalysts for Selective Oxidation of Propane to Acrylic Acid
title_full_unstemmed	Modification and Characterisation of Vanadium Phosphorus Oxide Catalysts for Selective Oxidation of Propane to Acrylic Acid
title_sort	modification and characterisation of vanadium phosphorus oxide catalysts for selective oxidation of propane to acrylic acid
granting_institution	Universiti Putra Malaysia
granting_department	Faculty of Science
publishDate	2006
url	http://psasir.upm.edu.my/id/eprint/564/1/FS_2006_30.pdf
_version_	1747810249920741376

Modification and Characterisation of Vanadium Phosphorus Oxide Catalysts for Selective Oxidation of Propane to Acrylic Acid

Similar Items