01232nas 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-002588nas a2200277   4500008004100000022001400041245009400055210006900149260007300218300001200291490000600303520161000309653001401919653002601933653002401959653002401983653001902007653001302026100001502039700002202054700001702076700002602093700003502119700002802154856012802182       2008                        eng d  a1566-736700aSynthesis of biodiesel over zirconia-supported isopoly and heteropoly tungstate catalysts0 aSynthesis of biodiesel over zirconiasupported isopoly and hetero  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR  a696-7020 v93 a<p>The liquid-phase synthesis of biodiesel by transesterification of sunflower oil with methanol is carried out by using zirconia-supported isopoly and heteropoly tungstates (HPAs) as catalysts. The isopoly and heteropoly tungstate catalysts were prepared by suspending zirconium oxyhydroxide in water/methanol solution of ammonium metatungstate/silicotungstic acid, phosphotungstic acid (WO3/HPA loading, 15%,,) followed by drying and calcination at 750 degrees C. The catalysts were characterized by XRD, Raman spectroscopy, IR spectroscopy, NH3-TPD and FTIR pyridine adsorption spectroscopy. XRD results indicate that the presence of isopoly and heteropoly tungstates stabilizes ZrO2 in tetragonal phase. Raman and IR spectra of the catalysts show that tungstate species exist as zirconia-anchored octahedral mono-oxotungstate. The acidity measurements by NH3-TPD and FTIR pyridine adsorption spectroscopy show that zirconia-supported phosphotungstate has the highest total acidity and zirconia-supported isopoly tungstate has the highest Bronsted acidity. The zirconia-supported isopoly tungstate shows superior catalytic performance compared to zirconia-supported heteropoly tungstate catalysts. Under the reaction conditions of 200 degrees C and methanol/oil molar ratio 15, 15% WO3/ZrO2 calcined at 750 degrees C gave 97% conversion of oil. This catalyst also efficiently catalyzes methanolysis of other vegetable oils like mustard oil and sesame oil. The deactivated catalyst could be regenerated by calcination without appreciable loss in activity. (c) 2007 Elsevier B.V. All rights reserved.</p>10aBiodiesel10aphosphotungstic acids10aSilicotungstic acid10atransesterification10atungsten oxide10aZirconia1 aSunita, G.1 aDevassy, Biju, M.1 aVinu, Ajayan1 aSawant, Dhanashri, P.1 aBalasubramanian, Veerappan, V.1 aHalligudi, Shivappa, B.  uhttps://library.ncl.res.in/content/synthesis-biodiesel-over-zirconia-supported-isopoly-and-heteropoly-tungstate-catalysts-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