02318nas a2200253   4500008004100000022001400041245009700055210006900152260007300221300001200294490000800306520143100314653001501745653002301760653001101783653001901794653001301813100001501826700002201841700002201863700002601885700002801911856012501939       2005                        eng d  a1381-116900aLiquid-phase alkylation of phenol with long-chain olefins over WOx/ZrO2 solid acid catalysts0 aLiquidphase alkylation of phenol with longchain olefins over WOx  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT  a123-1310 v2403 a<p>The liquid-phase alkylation of phenol with 1-dodecene was carried out over WOx/ZrO2 solid acid catalysts. The catalysts were prepared by wet impregnation method using zirconium oxyhydroxide and ammonium metatungstate. Catalysts with different WO3 loading (5-30 wt.%) were prepared and calcined at 800 degrees C and catalyst with 15% WO3 was calcined from 700-850 degrees C. All the catalysts were characterized by surface area, XRD, and FTIR. The catalyst with 15% WO3 calcined at 800 degrees C (15 WZ-800) was found to be the most active in the reaction. The effect of temperature, molar ratio and catalyst weight on dodecene conversion and products selectivity was studied in detail. Under the optimized reaction conditions of 120 degrees C, phenol/1-dodecene molar ratio 2 and time 2 h, the catalyst 15 WZ-800 gave &gt; 99% dodecene conversion with 90% dodecylphenol selectivity. Comparison of the catalytic activity of 15 WZ-800 with sulfated zirconia calcined at 500 degrees C (SZ-500) and HP zeolite showed that activity of SZ-500 was lower than that of 15 WZ-800, while HP zeolite showed negligible activity. It is observed that the presence of water in the reaction mixture was detrimental to the catalytic activity of WOx/ZrO2. The catalyst 15 WZ-800 also found to be an efficient catalyst for alkylation of phenol with long-chain olefins like 1-octene and 1-decene. (c) 2005 Elsevier B.V. All rights reserved.</p>10aAlkylation10along-chain olefins10aphenol10atungsten oxide10aZirconia1 aSarish, S.1 aDevassy, Biju, M.1 aBohringer, Walter1 aFletcher, Jack, C. Q.1 aHalligudi, Shivaraj, B.  uhttps://library.ncl.res.in/content/liquid-phase-alkylation-phenol-long-chain-olefins-over-woxzro2-solid-acid-catalysts-002005nas a2200253   4500008004100000022001400041245009000055210006900145260007300214300001200287490000800299520111400307653001101421653002401432653002001456653001301476100002201489700002101511700002601532700002201558700002601580700002801606856011701634       2005                        eng d  a1381-116900aSilicotungstate-modified zirconia as an efficient catalyst for phenol tert-butylation0 aSilicotungstatemodified zirconia as an efficient catalyst for ph  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY  a141-1460 v2333 a<p>The alkylation of phenol with tert-butanol was investigated using zirconia modified with silicotungstic acid (STA) as catalysts. The catalysts with different STA loading (5-25 wt.% calcined at 750 degrees C) and calcination temperature (15 wt.% calcined from 350 to 850 degrees C) were prepared and characterized by X-ray diffraction and NH3-TPD measurements. The XRD results indicate that STA stabilizes the tetragonal phase of zirconia. The catalyst with 15% STA on ZrO2 calcined at 750 degrees C shows the highest acidity and hence highest activity. Under the reaction conditions of 140 degrees C, tert-butanol/phenol molar ratio of 2 and LHSV of 4 h(-1), phenol conversion was 95.4% with selectivity to 2-tert-butyl phenol 4.3%, 4-tert-butyl phenol 59.2% and 2,4-di-tert-butyl phenol 35.8%. The reaction was studied as a function of time for 50 It without appreciable change in phenol conversion and product selectivity. The deactivated catalyst could be regenerated by calcination with out appreciable lose in catalytic activity and product selectivity. (c) 2005 Elsevier B.V. All rights reserved.</p>10aphenol10aSilicotungstic acid10atert-butylation10aZirconia1 aDevassy, Biju, M.1 aShanbhag, G., V.1 aMirajkar, Subhash, P.1 aBohringer, Walter1 aFletcher, Jack, C. Q.1 aHalligudi, Shivaraj, B.  uhttps://library.ncl.res.in/content/silicotungstate-modified-zirconia-efficient-catalyst-phenol-tert-butylation-002208nas a2200241   4500008004100000022001400041245009900055210006900154260007300223300001200296490000800308520132100316653003001637653002301667653002501690653001301715100002201728700001701750700002201767700002601789700002801815856012301843       2005                        eng d  a1381-116900aSynthesis of linear alkyl benzenes over zirconia-supported 12-molybdophosphoric acid catalysts0 aSynthesis of linear alkyl benzenes over zirconiasupported 12moly  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL  a162-1670 v2363 a<p>The liquid-phase alkylation of benzene with 1-octene and 1-dodecene was investigated using zirconia-supported 12-molybdophosphoric acid (MPA) as catalyst. The catalysts with different MPA loading (5-25 wt.% calcined at 700 degrees C) and calcination temperature (15 wt.% calcined from 500 to 750 degrees C) were prepared by suspending zirconium oxyhydroxide in methanol solution of MPA followed by drying and calcination. These catalysts were characterized by X-ray diffraction, and P-31 MAS NMR spectroscopy measurements. The XRD results indicated that MPA stabilizes the tetragonal phase of zirconia. 3 1 P MAS NMR spectra show that the nature of phosphorous species depend on MPA loading and calcination temperature, and it show the existence of three types of phosphorous species, one is the Keggin unit and the other is the decomposition product of MPA and third one an unidentified species. FTIR pyridine adsorption on 15% MPA catalyst calcined at 700 degrees C showed the presence both Bronsted and Lewis acidity. Under the reaction conditions of 83 C, benzene/1-olefin molar ratio of 10 (time, 1 h), the most active catalyst, 15% MPA calcined at 700 C gave more than 90% olefin conversion with selectivity to 2-phenyl octane, 55% and 2-phenyl dodecane, 45%. (c) 2005 Elsevier B.V. All rights reserved.</p>10a12-molybdophosphoric acid10abenzene alkylation10alinear alkyl benzene10aZirconia1 aDevassy, Biju, M.1 aLefebvre, F.1 aBohringer, Walter1 aFletcher, Jack, C. Q.1 aHalligudi, Shivaraj, B.  uhttps://library.ncl.res.in/content/synthesis-linear-alkyl-benzenes-over-zirconia-supported-12-molybdophosphoric-acid-002048nas a2200253   4500008004100000022001400041245010100055210006900156260007300225300001200298490000800310520115200318653001601470653001101486653002501497653001301522100002201535700002101557700001701578700002201595700002601617700002801643856012301671       2005                        eng d  a1381-116900aZirconia-supported phosphotungstic acid as catalyst for alkylation of phenol with benzyl alcohol0 aZirconiasupported phosphotungstic acid as catalyst for alkylatio  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a113-1190 v2303 a<p>The liquid-phase alkylation of phenol with benzyl alcohol was carried out using zirconia-supported phosphotungstic acid (PTA) as catalyst. The catalysts with different PTA loadings (5-20 wt.% calcined at 750 degrees C) and calcination temperature (15 wt.% calcined from 650 to 850 degrees C) were prepared and characterized by (31)p MAS NMR and FT-IR pyridine adsorption spectroscopy. The catalyst with optimum PTA loading (15%) and calcination temperature (750 degrees C) was prepared in different solvents. 31p MAS NMR spectra of the catalysts showed two types of phosphorous species, one is the Keggin unit and the other is the decomposition product of PTA and the relative amount of each depends on PTA loading, calcination temperature and the solvent used for the catalyst preparation. The catalysts with 15% PTA on zirconia calcined at 750 degrees C showed the highest Bronsted acidity. At 130 degrees C and phenol/benzyl alcohol molar ratio of 2 (time, I h), the most active catalyst, 15% PTA calcined at 750 degrees C gave 98% benzyl alcohol conversion with 83% benzyl phenol selectivity. (c) 2004 Elsevier B.V. All rights reserved.</p>10aBenzylation10aphenol10aPhosphotungstic acid10aZirconia1 aDevassy, Biju, M.1 aShanbhag, G., V.1 aLefebvre, F.1 aBohringer, Walter1 aFletcher, Jack, C. Q.1 aHalligudi, Shivaraj, B.  uhttps://library.ncl.res.in/content/zirconia-supported-phosphotungstic-acid-catalyst-alkylation-phenol-benzyl-alcohol-001232nas a2200289   4500008004100000022001400041245012700055210006900182260007300251300001400324490000600338520019500344653001100539653001100550653002400561653001900585653002700604653001300631100001900644700001700663700002200680700003500702700002200737700002600759700002800785856012900813       2008                        eng d  a1566-736700aHighly efficient and chemo selective catalyst system for the synthesis of blossom orange fragrance and flavoring compounds0 aHighly efficient and chemo selective catalyst system for the syn  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a1671-16750 v93 a<p>{Acetal and acylal formation reactions of organic compounds are efficiently catalyzed by zirconia-supported mixed oxide systems under liquid-phase reaction conditions. 15WZ-750 (where</p>10aAcetal10aacylal10aSilicotungstic acid10atungsten oxide10atungstophosphoric acid10aZirconia1 aJustus, Josena1 aVinu, Ajayan1 aDevassy, Biju, M.1 aBalasubramanian, Veerappan, V.1 aBohringer, Walter1 aFletcher, Jack, C. Q.1 aHalligudi, Shivaraj, B.  uhttps://library.ncl.res.in/content/highly-efficient-and-chemo-selective-catalyst-system-synthesis-blossom-orange-fragrance-002266nas a2200277   4500008004100000022001400041245013300055210006900188260007300257300001000330490000800340520126100348653002401609653001501633653002301648653001301671100001901684700002001703700002101723700002301744700001701767700002201784700002601806700002801832856012801860       2009                        eng d  a0926-860X00aComparative study on liquid phase alkylation of 2-methylnaphthalene with long chain olefins using different solid acid catalysts0 aComparative study on liquid phase alkylation of 2methylnaphthale  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN  a74-800 v3523 a<p>A comparative study has been made over a variety of solid acid catalysts, which include isopoly and heteropoly ions supported on various supports such as zirconia, titania, a large variety of zeolites and a couple of mesoporous materials for liquid phasealkylation of 2-methylnaphthalene with 1-octene.All the catalyst systems were characterized by nitrogen sorption analysis, X-ray diffraction and NH(3)-TPD. Inspite of their high acid amounts zeolites gave poor catalytic performance due to their diffusional constraints; on the other hand mesoporous materials lacked diffusional constraints but due to their low acid amounts resulted in poor conversions. lsopoly and heteropoly ions supported on zirconia and titania were found to be catalytically active for the reaction due to total surface acidity. Among them, isopolytungstate supported on zirconia exhibited the best catalytic activity and was used for further optimization of reaction conditions. Excellent conversions of all olefins (&gt;92%) with high selectivity of monoalkylmethylnaphthalene (&gt;95%) was obtained under optimized reaction conditions. The catalyst could be recycled for several times without any obvious loss of its activity. (C) 2008 Elsevier B.V. All rights reserved.</p>10a2-Methylnaphthalene10aAlkylation10aLong chain olefins10aZirconia1 aLucas, Nishita1 aBordoloi, Ankur1 aAmrute, Amol, P.1 aKasinathan, Palraj1 aVinu, Ajayan1 aBohringer, Walter1 aFletcher, Jack, C. Q.1 aHalligudi, Shivaraj, B.  uhttps://library.ncl.res.in/content/comparative-study-liquid-phase-alkylation-2-methylnaphthalene-long-chain-olefins-using-0