Monolayer V2O5/TiO2-ZrO2 catalysts for selective oxidation of o-xylene: preparation and characterization

Title
Monolayer V2O5/TiO2-ZrO2 catalysts for selective oxidation of o-xylene: preparation and characterization
Authors
Komateedi Narayana RaoPerala VenkataswamyPankaj Bharali하헌필Benjaram M. Reddy
Keywords
Selective oxidation; V2O5 dispersion; thermal stability; conversion; TiO2-ZrO2; Redox properties; o-Xylene; Phthalic anhydride
Issue Date
2012-03
Publisher
Research on chemical intermediates
Citation
VOL 38, NO 3-5, 733-744
Abstract
A series of TiO2–ZrO2 supported V2O5 catalysts with vanadia loadings ranging from 4 to 12 wt% were synthesized by a wet impregnation technique and subjected to various thermal treatments at temperatures ranging from 773 to 1,073 K to understand the dispersion and thermal stability of the catalysts. The prepared catalysts were characterized by X-ray powder diffraction (XRD), BET surface area, oxygen uptake, and X-ray photoelectron spectroscopy (XPS) techniques. XRD results of 773 K calcined samples conferred an amorphous nature of the mixed oxide support and a highly dispersed form of vanadium oxide. Oxygen uptake measurements supported the formation of a monolayer of vanadium oxide over the thermally stable TiO2–ZrO2 support. The O 1s, Ti 2p, Zr 3d, and V 2p core level photoelectron peaks of TiO2–ZrO2 and V2O5/TiO2–ZrO2 catalysts are sensitive to the calcination temperature. No significant changes in the oxidation states of Ti4? and Zr4? were noted with increasing thermal treatments. Vanadium oxide stabilized as V4? at lower temperatures, and the presence of V5? is observed at 1,073 K. The synthesized catalysts were evaluated for selective oxidation of o-xylene under normal atmospheric pressure in the temperature range of 600–708 K. The TiO2–ZrO2 support exhibits very less conversion of o-xylene, while 12 wt% V2O5 loaded sample exhibited a good conversion and a high product selectivity towards the desired product, phthalic anhydride.
URI
http://pubs.kist.re.kr/handle/201004/41011
ISSN
0922-6168
Appears in Collections:
KIST Publication > Article
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE