02048nas 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

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.

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-002440nas a2200253 4500008004100000022001400041245010300055210006900158260007300227300000900300490000800309520155700317653001401874653001501888653001201903653001801915653002501933653002401958653001401982653001301996100002202009700002802031856012702059 2006 eng d a1381-116900aEffect of calcination temperature on the catalytic activity of zirconia-supported heteropoly acids0 aEffect of calcination temperature on the catalytic activity of z aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a8-150 v2533 a

Zirconia-supported silicotungstic acid (15% STA) catalyst with different calcination temperatures (600-850 degrees C) was prepared by suspending zirconium oxyhydroxide in methanol solution of STA followed by drying and calcination. These catalysts were characterized by XRD, FTIR pyridine adsorption and DRUV-vis spectroscopy. The catalysts showed both Bronsted as well as Lewis acidity and 15% STA on zirconia calcined at 750 degrees C (15 SZ-750) had the highest Bronsted acidity. Characterization of 15 SZ-750 catalyst by Raman spectroscopy showed the presence of zirconia-anchored mono-oxotungstate as the major tungsten species present in this catalyst. These catalysts were used in benzoylation of veratrole with benzoic anhydride and 15 SZ-750 catalyst showed the highest activity. For catalyst with support calcined at different temperatures before HPA impregnation, catalytic activity decreases as the support calcination temperature increases due to the decrease in Bronsted acidity. Comparison of the catalytic activity of 15 SZ-750 with that of zirconia-supported phosphotungstic acid (15%, calcined at 750 degrees C, 15 PZ-750) in benzoylation of veratrole with benzoic anhydride, acylation of anisole with acetic anhydride and in alkylation of diphenylether with 1-dodecene showed that 15 SZ-750 catalyst has higher activity and deactivation resistance due to its higher Bronsted acidity. The deactivated catalyst could be regenerated by calcination without appreciable loss in activity. (c) 2006 Elsevier B.V. All rights reserved.

10aAcylation10aAlkylation10aAnisole10adiphenylether10aPhosphotungstic acid10aSilicotungstic acid10averatrole10aZirconia1 aDevassy, Biju, M.1 aHalligudi, Shivaraj, B. uhttps://library.ncl.res.in/content/effect-calcination-temperature-catalytic-activity-zirconia-supported-heteropoly-acids-001487nas a2200229 4500008004100000022001400041245013100055210006900186260007300255300001200328490000600340520058300346653002400929653003300953653002500986100002201011700002901033700002401062700002301086700002001109856012801129 2007 eng d a1566-736700aPhosphotungstic acid as an efficient solid catalyst for intramolecular rearrangement of benzyl phenyl ether to 2-benzyl phenol0 aPhosphotungstic acid as an efficient solid catalyst for intramol aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB a139-1440 v83 a

An heteropoly acid (phosphotungstic acid, PTA) was found to be a promising solid acid catalyst as an alternative to the conventional stoichiometric reagents for the rearrangement of benzyl phenyl ether giving 2-benzyl phenol as a major product and 4-benzyl phenol and dibenzylated phenols as side products. Catalyst was recovered from the reaction mixture and reused again without loss of activity. Based on the observed product distribution for various substrates a plausible catalytic reaction pathway has also been proposed. (c) 2006 Elsevier B.V. All rights reserved.

10abenzyl phenyl ether10aIntramolecular rearrangement10aPhosphotungstic acid1 aBhure, Mahesh, H.1 aRode, Chandrashekhar, V.1 aChikate, Rajeev, C.1 aPatwardhan, Neeraj1 aPatil, Shraddha uhttps://library.ncl.res.in/content/phosphotungstic-acid-efficient-solid-catalyst-intramolecular-rearrangement-benzyl-phenyl01635nas a2200265 4500008004100000022001400041245010100055210006900156260007300225300001000298490000800308520069500316653001401011653001301025653002501038653001501063653001401078653002201092100002901114700002701143700002401170700001901194700002401213856013201237 2014 eng d a0926-860X00aRegioselective acylation of 2-methoxy naphthalene catalyzed by supported 12-phosphotungstic acid0 aRegioselective acylation of 2methoxy naphthalene catalyzed by su aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a55-610 v4863 a

12-Phosphotungstic acid supported on silica gel, zirconium sulfate, and a combination of silica gel and zirconium sulfate (50% w/w) were employed as solid acid catalysts for regioselective acylation of 2-methoxynaphtalene with acetic anhydride. 1-(6-Methoxynaphthalen-2-yl)ethanone (2,6-AMN), a commercially important intermediate for production of Naproxen, was obtained with excellent selectivity (>98%) at 67-68% conversion using 12-phosphotungstic acid supported on silica gel 20% (w/w) in refluxing tetrachloroethane. The unreacted starting material can be easily separated from the product by a simple crystallization from nonane. (C) 2014 Elsevier B.V. All rights reserved.

10aAcylation10aNaproxen10aPhosphotungstic acid10aSilica gel10aSupported10aZirconium sulfate1 aKumaraguru, Thenkrishnan1 aDevi, Ayala, Vedamayee1 aSiddaiah, Vidavalur1 aRajdeo, Kishor1 aFadnavis, Nitin, W. uhttps://library.ncl.res.in/content/regioselective-acylation-2-methoxy-naphthalene-catalyzed-supported-12-phosphotungstic-acid-001935nas a2200205 4500008004100000022001100041245007300052210006900125260000800194300001000202490000800212520126100220653003001481653003101511653002501542653001101567100002301578700002901601856009901630 2018 eng d a16236100aSynthesis of diesel additives from fructose over PWA/SBA-15 catalyst0 aSynthesis of diesel additives from fructose over PWASBA15 cataly cJAN a38-440 v2173 aA series of composites of phosphotungstic acid (PWA) H3PW12O40 with SBA-15 were prepared by varying PWA amount from 5% to 30% by one-step sol-gel hydrothermal as well as by impregnation methods. Successful incorporation of PWA into the SBA-15 framework by sol-gel method was confirmed by 31P NMR in which a shifting of the peak due to tetrahedral ‘P’ atom of PWA from −14.32 and −14.49 ppm was observed. The composites exhibited both Brønsted and Lewis acidity, large and well distributed three dimensional interconnected pores with high surface areas exhibiting excellent activity for one pot synthesis of 5-(hydroxymethyl) furfural (5-HMF) and 5-(ethoxymethyl) furfural (EMF) from fructose. The minimum loading of 5% of PWA in SBA-15, gave 78% fructose conversion with the highest yield of 70% towards 5-HMF. Increase in PWA loading up to 20% resulted in the enhanced fructose conversion of 95% accompanied by further etherification of 5-HMF to 67 and 12% yield towards EMF and ethyl levulinate (EL), respectively. Increasing the % of PWA in SBA-15 matrix resulted in increase in the acidity of the composites giving the yield trend as 5-HMF < EMF < EL. Catalyst prepared by sol-gel method showed excellent recyclability up to 3 reuses10a5-(Ethoxymethyl) furfural10a5-(Hydroxymethyl) furfural10aPhosphotungstic acid10aSBA-151 aPatil, Chetana, R.1 aRode, Chandrashekhar, V. uhttps://library.ncl.res.in/content/synthesis-diesel-additives-fructose-over-pwasba-15-catalyst01968nas a2200217 4500008004100000022001400041245013000055210006900185260000800254300001100262490000800273520120800281653001601489653001901505653001901524653002501543653001901568100001801587700001801605856012701623 2022 eng d a2468-823100aImmobilization of HPW on UiO-66-NH2 MOF as efficient catalyst for synthesis of furfuryl ether and alkyl levulinate as biofuel0 aImmobilization of HPW on UiO66NH2 MOF as efficient catalyst for  cOCT a1126890 v5313 a

Phosphotungustic Acid (HPW) is an inorganic super acid, that is highly soluble in polar solvents limiting its applicability as acid catalysis. To overcome these limitations immobilization of HPW was carried out at room temperature by protonation of-NH2 group of UiO-66-NH2 MOF to UiO-66-NH2-HPW. ATR-FTIR spectroscopy and XPS results confirmed the protonation and chemical interaction between HPW and UiO-66-NH2. STEM-EDS mapping showed homogeneous distribution of HPW on UiO-66-NH2. BET and NH3-TPD confirmed the reduction in specific surface area, total pore volume, and increase in total acidity for UiO-66-NH2-HPW. Further, powder XRD, SEM, and HR-TEM prevailed that there is no change in phase and morphology after post-synthetic modification of UiO-66-NH2. The prepared catalyst is found to be effective for etherification and alcoholysis of furfuryl alcohol (FALc) to Furfuryl ether (FE) and Alkyl levulinate (AL). UiO-66-NH2-HPW has shown 97 mol % FALc conversions in ethanolic media and 31 mol% Ethyl furfuryl ether (EFE) yield and 29 mol% Ethyl lev-ulinate (EL) yield. UiO-66-NH2-HPW is also found to be efficient for the multistep conversion of Furfural (FFR) to FALc, FE, and AL.

10aAlcoholysis10aetherification10aImmobilization10aPhosphotungstic acid10aUiO-66-NH2-HPW1 aMulik, Nagesh1 aBokade, Vijay uhttps://library.ncl.res.in/content/immobilization-hpw-uio-66-nh2-mof-efficient-catalyst-synthesis-furfuryl-ether-and-alkyl