NISCAIR Online Periodicals Repository

Research Journals >
Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.14 [2007] >
IJCT Vol.14(4) [July 2007] >

Title: Ammoxidation of methylaromatics over VPO/SiO₂ catalysts
Authors: Guang-yong, Xie
Chi, Huang
Keywords: Ammoxidation
VPO/SiO₂ catalyst
Aromatic nitriles
Issue Date: Jul-2007
Publisher: CSIR
IPC CodeB01J21/06, C07C255/00
Abstract: Ammoxidation of methyl aromatics to their corresponding nitriles over silica-supported vanadium phosphorus oxide (VPO/SiO₂) catalysts has been studied. The effects of carrier silica, the addition of phosphorus, the substituents and the loadings on catalytic performances have been discussed. Compared with unsupported VPO, the VPO/SiO₂ catalysts have higher catalytic activity for ammoxidation of substituted toluenes at much lower reaction temperature. XPS shows that vanadium and phosphorus exist mainly in the pentavalent state in the VPO/SiO₂catalysts. XRD shows that vanadium phosphorus oxides exist as amorphous phase in 10 wt.% catalyst. When the loadings are over 10 wt.%, the crystalline ⍺-VOPO₄ would emerge, which would decrease the yield and selectivity. Additional phosphorus can inhibit the formation of crystalline V₂O₅ and form amorphous composite oxides with vanadia, which play concerted catalytic function and increase the selectivity of nitriles remarkably. The methyl aromatics with different substituents or same substituents on diffetent positions have different catalytic activities because of the variant electronic stability of intermediates, the hindered accessibility of methyl group or the chemisorption state of the substrate molecule on the electrophilic catalyst surface.
Page(s): 371-375
ISSN: 0971–457X
Source:IJCT Vol.14(4) [July 2007]

Files in This Item:

File Description SizeFormat
IJCT 14(4) (2007) 371-375.pdf177.58 kBAdobe PDFView/Open
 Current Page Visits: 118 
Recommend this item


Online Submission of Articles |  NISCAIR Website |  National Knowledge Resources Consortium |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2015 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 163837 since 01-Sep-2015  Last updated on 21-Jun-2016Webmaster: