02531nas a2200277   4500008004100000022001400041245010800055210006900163260007300232300001200305490000800317520157300325653000601898653002601904653002901930653001501959653002001974653001301994653001702007653001202024100002302036700002102059700001702080700002802097856012802125       2006                        eng d  a1381-116900aHeteropoly acid supported on titania as solid acid catalyst in alkylation of p-cresol with tert-butanol0 aHeteropoly acid supported on titania as solid acid catalyst in a  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a324-3340 v2563 a<p>Butylation of p-cresol with tert-butanol was investigated on titania modified with 12-tungstophosphoric acid (TPA/TiO2) catalyst under vapor phase conditions. Catalysts with different TPA loadings (10-25 wt.%) and calcination temperatures (650-750 degrees C) were prepared by suspending titanium hydroxide in methanol solution of TPA followed by drying and calcination. These catalysts were characterized by surface area, XRD, P-31 MAS NMR, XPS, NH3-TPD, and FTIR pyridine adsorption. XRD results indicated that the presence of TPA retarded the crystallization of titania and stabilized TiO2 in anatase phase. P-31 MAS NMR indicated the presence of TPA in various forms (dispersed, highly fragmented and Keggin intact). These catalysts showed both Bronsted and Lewis acidity, and 20% TPA on TiO2 calcined at 700 degrees C (from here after words 20% TT 700) had the highest Bronsted as well as total acidity. Further, the catalytic activities were examined in tert-butylation of p-cresol with tent-butanol. The catalytic activity depended on TPA coverage, and the highest activity corresponded to the monolayer of TPA on titania. The most active catalyst 20% TT-700 gave 82% conversion of p-cresol and 89.5% selectivity towards 2-tert-butyl cresol (TBC), 2,6-di-tert-butyl cresol (DTBC) 7.5% and cresol-tert-butyl ether (CTBE) 3% under optimized conditions. The activity was always higher than that of WO3/ZrO2, sulfated zirconia (SZ), USY, H-beta zeolites and montmorillonite K-10 (K-10mont) under similar conditions. (c) 2006 Elsevier B.V. All rights reserved.</p>10a210a2-tert-butyl-p-cresol10a6-di-tert-butyl-p-cresol10aAlkylation10aheteropoly acid10ap-Cresol10atert-butanol10atitania1 aKumbar, Suresh, M.1 aShanbhag, G., V.1 aLefebvre, F.1 aHalligudi, Shivaraj, B.  uhttps://library.ncl.res.in/content/heteropoly-acid-supported-titania-solid-acid-catalyst-alkylation-p-cresol-tert-butanol-0