02639nas a2200277   4500008004100000022001400041245007500055210006900130260007300199300001000272490000800282520174600290653001302036653001802049653001402067653002002081653001602101100001902117700001402136700002802150700001902178700002302197700001602220700001602236856010902252       2005                        eng d  a1381-116900aVapor phase oxidation of 4-fluorotoluene over vanadia-titania catalyst0 aVapor phase oxidation of 4fluorotoluene over vanadiatitania cata  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN  a51-570 v2343 a<p>The vapor phase oxidation of 4-fluorotoluene has been carried out over vanadia-titania catalysts with moderate conversion and selectivity for 4-fluorobenzaldehyde. Two series of V2O5/TiO2 catalysts with 1-10 mol% vanadia were prepared by sol-gel technique using vanadium and titanium peroxide as vanadia and titania precursors respectively and by impregnation technique using vanadium peroxide on anatase titania support. The samples were characterized by X-ray diffraction, NH3-TPD, FT-IR and BET surface area measurements. The XRD of the catalysts prepared by impregnation technique showed retention of the anatase titania whereas the catalysts prepared by sol-gel technique showed the formation of rutile titania with minor amount of anatase phase at lower vanadia content (1-3 %), which completely transformed into anatase phase at higher vanadia loading. The samples prepared by sol-gel method showed higher acidity and surface area compared to the samples prepared by impregnation. Pyridine adsorption study by FT-IR revealed the presence of Lewis acidity at lower vanadia loading (1-3 %) and presence of both Lewis as well as Bronsted acidity at higher vanadia loading. The catalytic activity for oxidation of 4-fluorotoluene increased with vanadia loading in the sol-gel catalysts. The catalysts prepared by impregnation technique were found to be less active. However the selectivity for 4-fluorobenzaldehyde decreased with increase in vanadia content. The influence of vanadia loading, reaction temperature and contact time on the catalytic activity for 4-fluorotoluene oxidation has been investigated. The structure of the catalyst and its catalytic activity has been correlated. (c) 2005 Elsevier B.V. All rights reserved.</p>10aCatalyst10afluorotoluene10aOxidation10avanadia-titania10avapor phase1 aMaurya, S., K.1 aPatil, P.1 aUmbarkar, Shubhangi, B.1 aGurjar, M., K.1 aDongare, Mohan, K.1 aRudiger, S.1 aKemnitz, E.  uhttps://library.ncl.res.in/content/vapor-phase-oxidation-4-fluorotoluene-over-vanadia-titania-catalyst-0