02017nas a2200229 4500008004100000022001400041245009200055210006900147260007300216300001200289490000800301520122000309653001501529653002701544653001501571653001201586653000801598653001301606100001901619700002801638856012101666 2005 eng d a1381-116900aAlkylation of benzene with alpha-olefins over zirconia supported 12-silicotungstic acid0 aAlkylation of benzene with alphaolefins over zirconia supported  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG a137-1450 v2373 a

Liquid phase alkylation of benzene to linear alkyl benzene (LAB) with alpha-olefins has been investigated with 12-silicotungstic acid supported on zirconia (STA/ZrO2) as the catalyst. Among the catalysts, 15 wt.% STA/ZrO2 calcined at 750 degrees C was found to be most active than others in the alkylation reaction. The total amount of acid sites of different STA loaded catalysts were estimated by TPD of NH3 and 15 wt.% STA/ZrO2 calcined at 750 degrees C was found to have the highest acidity and more active in the reaction. The optimization of reaction conditions of alkylation of benzene with 1-dodecene was performed with 15 wt.% STA/ZrO2 calcined at 750 degrees C by varying catalyst concentration (1-5 wt.% of reaction mixture); temperature, 373-423 K and benzene: 1-dodecene (1-dd) molar ratio, 5-15 in a Parr autoclave under N-2 pressure. Under the optimized reaction conditions, conversion of 1-dodecene (50.8%) gave high selectivity to 2-phenyl dodecane (47.1%) and the remaining 3-, 4-, 5- and 6-phenyldodecanes in 4 h. The reaction was found to be heterogeneously catalyzed and no contribution from homogeneous (leached) STA into the reaction medium. (c) 2005 Elsevier B.V. All rights reserved.

10a1-dodecene10a12-silicotungstic acid10aAlkylation10aBenzene10aLAB10aZirconia1 aSawant, D., P.1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/alkylation-benzene-alpha-olefins-over-zirconia-supported-12-silicotungstic-acid-002262nas a2200241 4500008004100000022001400041245010100055210006900156260007300225300001200298490000700310520141400317653001501731653001301746653001601759653001101775100001301786700001901799700002101818700002101839700002801860856013201888 2005 eng d a1387-181100aBenzylation of benzene and other aromatics by benzyl chloride over mesoporous AlSBA-15 catalysts0 aBenzylation of benzene and other aromatics by benzyl chloride ov aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a195-2030 v803 a

Aluminum-containing mesoporous molecular sieves AISBA-15 with different n(Si)/n(Al), ratios and AIMCM-41 have been synthesized hydrothermally and characterized in detail by physicochemical methods, viz. XRD, N(2) adsorption and (27)Al NMR spectroscopy. The low angle XRD and N2 adsorption measurements reveal that the structural order of SBA-15 was retained after the incorporation of Al. The increase of the unit cell parameter with increasing aluminum content and (27)Al MAS NMR spectroscopy confirm the incorporation of aluminum in the framework. Benzylation of benzene and substituted benzenes reaction employing benzyl chloride as the alkylating agent over AISBA-15 and AIMCM-41 have been investigated. The influence of various reaction parameters such as reaction temperature, reactant feed ratio and catalyst amount affecting the activity and selectivity of AISBA-15, have been studied. Among the mesoporous catalysts studied, AISBA-15(45), where the number in parentheses indicates the molar nsilnA, ratio, shows both high conversion and high selectivity for the benzylation of benzene. The activity of this catalyst for the benzylation of different aromatic compounds is in the following order: benzene > toluene > p-xylene > mesitylene > anisole. Kinetics of the benzene benzylation over different catalysts have also been investigated. (c) 2005 Elsevier Inc. All rights reserved.

10aAlkylation10aAlSBA-1510aBenzylation10aSBA-151 aVinu, A.1 aSawant, D., P.1 aAriga, Katsuhiko1 aHartmann, Martin1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/benzylation-benzene-and-other-aromatics-benzyl-chloride-over-mesoporous-alsba-15-catalysts-002326nas a2200241 4500008004100000022001400041245018300055210006900238260007300307300001200380490000800392520131100400653001801711653002901729653005701758653003301815653002301848100002301871700001701894700001901911700002801930856012601958 2005 eng d a1381-116900aBis(2-[alpha-hydroxyethyl]benzimidazolato)copper(II) anchored onto chloromethylated polystyrene for the biomimetic oxidative coupling of 2-aminophenol to 2-aminophenoxazine-3-one0 aBis2alphahydroxyethylbenzimidazolatocopperII anchored onto chlor aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a132-1380 v2363 a

2-(alpha-Hydroxyethyl)benzimidazole (Hhebmz) has been covalently anchored to chloromethylated polystyrene cross-linked with 5% divinylbenzene. This polymer-anchored chelating resin reacts with cupric acetate in presence of Hhebmz to give polymer-anchored copper(II) complex PS-[Cu(hebmz)(2)]. Elemental analyses, FT-IR, electronic, scanning electron micrographs (SEM) and TGA-DTA pattern have been used to characterize the complex. Oxidative coupling of 2-aminophenol (OAP) to 2-aminophenoxazine-3-one (APX) catalyzed by PS-[Cu(hebmz)(2)] in presence of air at 70 degrees C in DMF gave 62% substrate conversion over a period of 8 h. Kinetics of the above reaction indicated that the rate of oxidative coupling of OAP has a first order dependence with respect to substrate, catalyst and air pressure (dissolved O-2) concentrations in the range of conditions evaluated. Based on these observations, a plausible mechanism for the above reaction has been proposed. From, the study on the effect of temperature on the rates of oxidative coupling, an activation energy 34.2 kcal/degree mole was evaluated from Arrhenius plot of -ln rate versus 1/T. Enthalpy, entropy and free energy were calculated using standard thermodynamic equations for the above reaction. (c) 2005 Elsevier B.V. All rights reserved.

10a2-aminophenol10a2-aminophenoxazine-3-one10abis(2-[alpha-hydroxyethyl]benzimidazolato)copper(II)10achloromethylated polystyrene10aoxidative coupling1 aMaurya, Mannar, R.1 aSikarwar, S.1 aJoseph, Trissa1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/bis2-alpha-hydroxyethylbenzimidazolatocopperii-anchored-chloromethylated-polystyrene-101799nas a2200217 4500008004100000022001400041245013000055210006900185260007300254300001200327490000800339520095800347653001001305653003201315653002701347653001701374100001901391700001401410700002801424856012901452 2005 eng d a1381-116900aBronsted acidic ionic liquids: a green, efficient and reusable catalyst system and reaction medium for fischer esterification0 aBronsted acidic ionic liquids a green efficient and reusable cat aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUN a107-1100 v2343 a

Bronsted acidic ionic liquid containing nitrogen-based organic cations 1-methylimidazole and 1-butyl-3-methylimidazolium and inorganic anions of the type BF4-, PF6- and PTSA(-) has been synthesized in good yields and used as a catalysts and reaction medium for Fischer esterification of alcohols with acids. These were characterized using FTIR and NMR spectroscopy. Ionic liquids as catalyst afforded good alcohol conversion and excellent ester selectivity. Fischer esterification of acetic acid with benzyl alcohol with different Bronsted acidic ionic liquids was carried out. Maximum substrate conversion 100 % and product selectivity 100 % was observed on using [BMIM](+)PTSAas catalyst over a period of 2 h. The ester was easily separated from the reaction mixture and the ionic liquid was reused four times after removing water. No significant loss in catalytic activity was observed on recycling. (c) 2005 Elsevier B.V. All rights reserved.

10aacids10aalcohol and reaction medium10aFischer esterification10aIonic liquid1 aJoseph, Trissa1 aSahoo, S.1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/bronsted-acidic-ionic-liquids-green-efficient-and-reusable-catalyst-system-and-reaction-101890nas a2200241 4500008004100000022001400041245011100055210006900166260007300235300001200308490000800320520101700328653001101345653001201356653001301368653001901381653003001400653002101430100001901451700002101470700002801491856012901519 2005 eng d a1381-116900aCopper(II) ion-exchanged montmorillonite as catalyst for the direct addition of N-H bond to CC triple bond0 aCopperII ionexchanged montmorillonite as catalyst for the direct aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL a139-1440 v2363 a

An efficient synthesis of phenyl-(1-phenylethylidene)amine using copper-exchanged montmorillonite clay (Cu K-10) is demonstrated. The catalyst was characterized using UV-vis, XRD, BET surface area measurements, pyridine adsorption etc. The XRD and surface area measurement show that the structural characteristics of the support montmorillonite K-10 (K-10) are preserved after Cu exchange. The hydroamination of phenyl acetylene with aniline was carried out in toluene under reflux condition in N-2 atmosphere at 393 K. The reaction is highly regio-selective for only Markovnikoff's addition of an-tine to CC multiple bond and proceeded smoothly to completion. The reaction conditions were optimized to obtain complete conversion with respect to phenyl acetylene. Reaction data showed that the activity of the catalyst in hydroamination reaction is greater at higher reaction temperatures and nonpolar solvents and NZ pressure promotes the reaction drastically. (c) 2005 Elsevier B.V. All rights reserved.

10aalkyne10aAniline10aCatalyst10ahydroamination10aK-10 montmorillonite clay10aphenyl acetylene1 aJoseph, Trissa1 aShanbhag, G., V.1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/copperii-ion-exchanged-montmorillonite-catalyst-direct-addition-n-h-bond-cc-triple-bond-002478nas a2200217 4500008004100000022001400041245009700055210006900152260007100221300001400292490000700306520167900313100001301992700001902005700002102024700002002045700002802065700002102093700001502114856013102129 2005 eng d a0897-475600aDirect synthesis of well-ordered and unusually reactive FeSBA-15 mesoporous molecular sieves0 aDirect synthesis of wellordered and unusually reactive FeSBA15 m a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a5339-53450 v173 a

Large-pore hexagonal SBA-15 molecular sieves partially substituted with iron(III) have been synthesized for the first time in highly acidic media. The degree of iron(III) incorporation into SBA-15 can easily be controlled by a simple adjustment of the molar ratio of water and hydrochloric acid. All the materials have been characterized by XRD, N-2 adsorption, UV-Vis DRS, ESR, and XANES spectroscopy. The characterization of the FeSBA-15 materials by UV-Vis DRS, ESR, and XANES spectroscopies suggests that the iron atoms are highly dispersed and mostly occupy isolated tetrahedral sites. XANES studies revealed that the proportion of tetrahedrally coordinated Fe atoms decreases with decreasing n(Si)/n(Fc) ratios. Benzylation of benzene (or substituted benzenes) using benzyl chloride as the alkylating agent over FeSBA-15 with different n(Si)/n(Fe) ratios was investigated as was the same reaction using AISBA-15 as catalyst. The influence of parameters such as reaction temperature, reactant feed ratio, and the presence of electron-donating substituents on the activity and selectivity of AISBA-15 was studied. Under optimized reaction conditions, the FeSBA-15 catalyst showed a superior catalytic performance in the benzylation of benzene and other aromatics using benzyl chloride, with a clean conversion of benzyl chloride to the monoalkylated product (100% selectivity) with a very high rate constant when compared to other mesoporous materials such as AISBA-15 and FeHMS. Interestingly, use of FeSBA-15(21) resulted in quantitative conversion of benzyl chloride with a high rate constant of 2420.5 x 10(-4) min(-1) under the optimized reaction conditions.

1 aVinu, A.1 aSawant, D., P.1 aAriga, Katsuhiko1 aHossain, K., Z.1 aHalligudi, Shivappa, B.1 aHartmann, Martin1 aNomura, M. uhttps://library.ncl.res.in/content/direct-synthesis-well-ordered-and-unusually-reactive-fesba-15-mesoporous-molecular-sieves-002439nas a2200241 4500008004100000022001400041245017000055210006900225260009500294300001200389490000800401520147800409653001401887653003201901653002101933653001301954100001901967700001301986700002201999700001702021700002802038856013102066 2005 eng d a0021-951700aFormation of nanosized zirconia-supported 12-tungstophosphoric acid in mesoporous silica SBA-15: a stable and versatile solid acid catalyst for benzylation of phenol0 aFormation of nanosized zirconiasupported 12tungstophosphoric aci a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcOCT a341-3520 v2353 a

A nanosized zirconia-supported 12-tungstophosphoric acid (TPA) in SBA-15 composite was prepared by wet impregnation of TPA/ZrO2 nanoparticles inside the mesoporous channels of SBA-15. The resulting composite material was calcined at 1123 K and characterized by elemental analysis, powder X-ray diffraction, nitrogen adsorption isotherms, transmission electron microscopy (TEM), scanning electron microscopy (SEM), solid-state P-31 CP-MAS NMR, Si-29 MAS NMR, UV-vis diffuse reflectance spectra, FTIR, TPD of ammonia, FTIR pyridine adsorption, and thermogravimetric analysis (TG-DTG). The synthesized TPA/ZrO2/SBA-15 showed a well-ordered hexagonal inesoporous structure and mesoporous support SBA-15 stabilized ZrO2-t (tetragonal) phase with crystal size in the range of 3-4 nm. SBA-15 was a better support than MCM-41 and MCM-48 because it retained its mesostructure even after high TPA loading and high calcination temperatures. Mesoporous silica support plays an important role in stabilizing the catalytically active tetragonal phase of zirconia, which gave the most active catalysts. The catalysts were examined for their catalytic activities in the liquid phase benzylation of phenol with benzyl alcohol and the catalyst 15 wt% TPA/ 22.4 wt% ZrO2/SBA-15 calcined at 1123 K was found to have high acidity and to be 10 times more active than neat TPA/ZrO2 Under the reaction conditions studied in benzylation of phenol. (c) 2005 Elsevier Inc. All rights reserved.

10ananosized10aphenol benzylation reaction10aterragonal phase10aTPA/ZrO21 aSawant, D., P.1 aVinu, A.1 aJacob, Nalini, E.1 aLefebvre, F.1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/formation-nanosized-zirconia-supported-12-tungstophosphoric-acid-mesoporous-silica-sba-15-001726nas a2200217 4500008004100000022001400041245009400055210006900149260007300218300001200291490000800303520090900311653004101220653002901261653001301290653002501303653000801328100001901336700002801355856012501383 2005 eng d a1381-116900aOxyfunctionalization of limonene using vanadium complex anchored on functionalized SBA-150 aOxyfunctionalization of limonene using vanadium complex anchored aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR a241-2470 v2293 a

VO(Salten) complexes, where Salten = 3-[N,N'-bis-3(salicylidenamino)ethyltriamine], have been covalently anchored on to functionalized SBA-15. The formation and integrity of the complex have been confirmed by elemental analysis, Fr-IR, X-ray diffraction (XRD) and BET measurements and the complex was used for the oxyfunctionalization of limonene in presence of urea hydroperoxide (UHP) as the oxidizing agent. The oxyfunctionalization of limonene resulted in limonene oxide, carvone, carvacrol and carveol. Anchored complex showed better catalytic activity than the neat complex, while the neat complexes has deactivated in the reaction due to formation of inactive alpha-oxo-bridged dimers, the covalently anchored complexes remained stable throughout the reaction. The anchored complex could be easily separated from the products and could be reused. (C) 2004 Elsevier B.V. All rights reserved.

10acovalently anchored vanadium complex10afunctionalized Si-SBA-1510alimonene10aoxofunctionalization10aUHP1 aJoseph, Trissa1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/oxyfunctionalization-limonene-using-vanadium-complex-anchored-functionalized-sba-15-101408nas a2200241 4500008004100000022001400041245017900055210006900234260007300303300001000376490000700386520037900393653004100772653004300813653004500856653003100901100002300932700001700955700001900972700002800991700002801019856011901047 2005 eng d a1381-514800aSynthesis, characterization and catalytic potentials of polymer anchored copper(II), oxovanadium(IV) and dioxomolybdenum(VI) complexes of 2-(alpha-hydroxymethyl)benzimidazole0 aSynthesis characterization and catalytic potentials of polymer a aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR a71-830 v633 a

{2-(alpha-Hydroxymethyl)benzimidazole (Hhmbmz) has been covalently anchored to chloromethylated polystyrene cross-linked with 5% divinylbenzene. This chelating resin reacts with cupric acetate, vanadyl sulphate and [MoO(2)-(acac)(2)] (Hacac = acetylacetone) in presence of Hhmbmz to give complexes PS-[Cu(hmbmz)(2)], PS-[VO(hmbmz)(2)] and PS-[MoO(2)(hmbmz)(2)] (where

10a2-(alpha-hydroxymethyl)benzimidazole10aoxidation of styrene and ethyl benzene10aoxidative bromination of salicylaldehyde10apolymer anchored-complexes1 aMaurya, Mannar, R.1 aSikarwar, S.1 aJoseph, Trissa1 aManikandan, Palanichamy1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/synthesis-characterization-and-catalytic-potentials-polymer-anchored-copperii-102744nas a2200265 4500008004100000022001400041245012400055210006900179260007300248300001200321490000800333520176200341653001002103653001102113653003802124653002902162653002002191653001902211653003002230100001902260700002102279700001902300700002802319856013102347 2006 eng d a1381-116900aChemoselective anti-Markovnikov hydroamination of alpha,beta-ethylenic compounds with amines using montmorillonite clay0 aChemoselective antiMarkovnikov hydroamination of alphabetaethyle aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a210-2170 v2503 a

The catalytic activity of montmorillonite clays as a catalyst for the hydroamination of alpha,beta-ethylenic compounds with amines was tested. Aniline and substituted amines reacted with alpha,beta-ethylenic compounds in the presence of catalytic amount of commercially available clay to afford exclusively anti-Markovnikov adduct in excellent yields. Aniline reacted with ethyl acrylate to yield only anti-Markovnikov adduct N-[2-(ethoxycarbonyl)ethyl] aniline (mono-addition product). No Markovnikov adduct (N-[1-(ethoxycarbonyl)ethyl]aniline and double addition product N,N-bis[2-(ethoxycarbonyl)ethyl]aniline were formed under selected reaction conditions. For a better exploitation of the catalytic activity in terms of increased activity and improved selectivity for the mono-addition product, the reaction parameters were optimized in terms of temperature, solvent, reactant mole ratio. Under optimized reaction conditions, montmorillonite clay K-10 showed a superior catalytic performance in the hydroamination of ethyl acrylate with aniline with a conversion of aniline to mono-addition product (almost 100% chemoselectivity) with a high rate constant 0.3414 min(-1) compared to the reported protocols. The dependence of conversion of aniline over different types of montmorillonite clays (K-10, K-20, K-30, Al-Pillared clay and untreated clay) has also been discussed. The activities of clay for the hydroamination of different aromatic and aliphatic amines have also been investigated. Under harsh reaction conditions (increased temperature and long reaction time) small amounts of di-addition products were observed. The kinetics data has been interpreted using the initial rate approach model. (c) 2006 Elsevier B.V. All rights reserved.

10aalpha10aamines10aanti-Markovnikov addition product10abeta-ethylenic compounds10achemo-selective10ahydroamination10aK-10 montmorillonite clay1 aJoseph, Trissa1 aShanbhag, G., V.1 aSawant, D., P.1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/chemoselective-anti-markovnikov-hydroamination-alphabeta-ethylenic-compounds-amines-using-102980nas a2200289 4500008004100000022001400041245013400055210006900189260007600258300001400334490000700348520191000355653001902265653002502284653001702309653001902326653002402345100002602369700001902395700003502414700002102449700002402470700002002494700002802514700001702542856013102559 2008 eng d a0947-653900aHeteropoly acid encapsulated SBA-15/TiO(2) nanocomposites and their unusual performance in acid-catalysed organic transformations0 aHeteropoly acid encapsulated SBA15TiO2 nanocomposites and their  aCOMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USAbWILEY-BLACKWELLcFEB a3200-32120 v143 a

The preparation of SBA-15/TiO(2) nanocomposites with different loadings of Keggin-type 12-tungsto-phosphoric acid (TPA) nanocrystals in their mesochannels through a simple and effective vacuum impregnation method is reported for the first time. The catalysts have been characterised by various sophisticated techniques, including XRD, HRSEM, and TEM. It has been found that the acidity and the textural parameters of the nanocomposites can be controlled by simply changing the loadings of TPA and TiO(2) or the calcination temperature. TPA and TiO(2) loadings of 15 and 22.4 wt %, respectively, and a calcination temperature of 1123 K have proved to be optimal for obtaining mesoporous nanocomposite materials with the highest acidity. Moreover, the activities of these catalysts in promoting hydroamination as well as Mannich and Claisen rearrangement reactions have been extensively investigated. The results show that the amount of TPA has a great influence on the activity of the nanocomposites in all of the reactions studied. The effects of other reaction parameters, such as temperature and reaction time, on the conversion and product selectivity have also been studied in detail. A kinetic analysis of the formation of the products under various reaction conditions is presented. It has been found that the activity of the nanocomposite composed of 15 wt % TPA deposited on 22.4 wt of TiO(2) on SBA-15 in promoting the studied reaction is remarkably higher than the catalytic activities shown by pure TPA, TiO(2)-loaded SBA-15, or TPA-loaded SBA-15. The results obtained have indicated that the acidity and the structural control of the nanocomposite materials are highly critical for obtaining excellent catalytic activity, and the presented highly acidic nanocomposites are considered to show great potential for use as catalysts in promoting many acid-catalysed organic transformations.

10aBronsted acids10amesoporous materials10ananoreactors10ananotechnology10asupported catalysts1 aSawant, Dhanashri, P.1 aJustus, Josena1 aBalasubramanian, Veerappan, V.1 aAriga, Katsuhiko1 aSrinivasu, Pavuluri1 aVelmathi, Sivan1 aHalligudi, Shivappa, B.1 aVinu, Ajayan uhttps://library.ncl.res.in/content/heteropoly-acid-encapsulated-sba-15tio2-nanocomposites-and-their-unusual-performance-acid-001316nas a2200181 4500008004100000022001400041245012500055210006900180260007100249300001600320490000800336520056000344100002800904700001700932700002800949700003000977856012701007 2008 eng d a1932-744700aHighly selective catalytic hydrogenation of arenes using rhodium nanoparticles supported on multiwalled carbon nanotubes0 aHighly selective catalytic hydrogenation of arenes using rhodium a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a13317-133190 v1123 a

Rhodium nanoparticles (RhNPs; 4.9 +/- 0.4 nm) supported on multiwalled carbon nanotubes (Rh/MWNT), prepared by simple microwave treatment, show a remarkable catalytic activity for arene hydrogenation with enhanced turnover numbers of similar to 10000; disubstituted arenes show selective conversion of thermodynamically less favorable cis products (>80%). A series of arenes have been tested using various Rh-based catalysts, and a comparison of the results with that of reported rhodium catalysts shows unique selectivity under mild conditions.

1 aKakade, Bhalchandra, A.1 aSahoo, Suman1 aHalligudi, Shivappa, B.1 aPillai, Vijayamohanan, K. uhttps://library.ncl.res.in/content/highly-selective-catalytic-hydrogenation-arenes-using-rhodium-nanoparticles-supported-002735nas a2200253 4500008004100000022001400041245013200055210006900187260007700256300001200333490000700345520176600352100002402118700001502142700003502157700002002192700002602212700002302238700002602261700002102287700002802308700001702336856012802353 2008 eng d a1616-301X00aNovel three dimensional cubic Fm3m mesoporous aluminosilicates with tailored cage type pore structure and high aluminum content0 aNovel three dimensional cubic Fm3m mesoporous aluminosilicates w aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB a640-6510 v183 a

Novel three dimensional cubic Fm3m mesoporous aluminosilicates (AIKIT-5) with very high structural order and unprecedented loadings of Al in the silica framework have been successfully prepared for the first time by using non ionic surfactant as a template in a highly acidic medium. The obtained materials have been unambiguously characterized in detail by several sophisticated techniques such as XRD, N, adsorption, HRTEM, HRSEM, EDS, elemental mapping, Al-27 MAS NMR, and NH3-TPD. We also demonstrate that the nature, and the amount of Al incorporation in the silica framework can easily be controlled by simply varying the n(H2O)/n(HCl) and the n(Si)/n(Al), ratios, and the Al sources in the synthesis gel. Among the Al sources examined, the Al isopropoxide (AiPr) is superior over other Al sources. Al-27 MAS NMR results reveal that the amount of tetrahedral Al in the framework can be controlled by simply adjusting the nSi/nAl ratio in the synthesis gel, which increases with increasing the Al incorporation. One of the interesting findings in the work is the increase of the specific surface area, specific pore volume and the pore diameter of AIKIT-5 with increasing the Al incorporation in the silica framework (up to n(Si)/n(Al), ratio of 10) while retaining the well-ordered three dimensional cage type porous structure, and the mechanism for the unusual behavior has been discussed in detail. Finally, the acidity and the catalytic activity in the acetylation of veratrole of the AIKIT-5 catalysts have been studied and the results have been compared with the several zeolites catalysts. Among the catalysts examined, AIKIT-5(10) is found to be superior over the zeolites catalysts such as mordenite, zeolite H-Y, zeolite H-beta, and ZSM-5.

1 aSrinivasu, Pavuluri1 aAlam, Sher1 aBalasubramanian, Veerappan, V.1 aVelmathi, Sivan1 aSawant, Dhanashri, P.1 aBoehlmann, Winfred1 aMirajkar, Subhash, P.1 aAriga, Katsuhiko1 aHalligudi, Shivappa, B.1 aVinu, Ajayan uhttps://library.ncl.res.in/content/novel-three-dimensional-cubic-fm3m-mesoporous-aluminosilicates-tailored-cage-type-pore-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

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.

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-002420nas a2200289 4500008004100000022001400041245011000055210006900165260007700234300001400311490000600325520138300331653002101714653001901735653002501754653001801779100002801797700003501825700002101860700001901881700001701900700001901917700002401936700002801960700001701988856012502005 2014 eng d a1867-388000aTitania nanoparticles stabilized HPA in SBA-15 for the intermolecular hydroamination of activated olefins0 aTitania nanoparticles stabilized HPA in SBA15 for the intermolec aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcDEC a3347-33540 v63 a

A liquid phase hydroamination (HA) of alpha,beta-ethylenic compounds with amines was investigated with TiO2 nanoparticles stabilized 12-tungstophosphoric acid (TPA) in SBA-15. The catalysts were prepared by wet impregnation of TPA/TiO2 nanoparticles into the SBA-15 and calcined at different temperatures. The characterization results reveal that the textural properties and the acidity of the prepared catalysts can be finely controlled with the simple adjustment of the calcination temperature and the structure of the support, decorated with the TiO2 and TPA nanoparticles, was intact even after the modification. The prepared catalysts were investigated for HA of ethyl acrylate with different aromatic and aliphatic amines over a wide range of reaction conditions to optimize the yield and the selectivity of product. It was found that this process is 100% atom efficient and the catalytic performance depended significantly on the loading of TPA over the catalyst and the calcination temperature. Under optimized reaction conditions, the best catalyst, 15 wt% TPA/22.4 wt% TiO2/SBA-15 calcined at 1123 K, offered the highest conversion of p-ethylaniline (70%) with 100% chemo-selectivity to the anti-Markovnikov product, i.e., the mono-addition product. The reaction was heterogeneously catalyzed and no contribution from leached TPA into the reaction was observed.

10aheteropoly acids10ahydroamination10amesoporous materials10ananocatalysts1 aSawant-Dhuri, Dhanashri1 aBalasubramanian, Veerappan, V.1 aAriga, Katsuhiko1 aPark, Dae-Hwan1 aChoy, Jin-Ho1 aCha, Wang, Soo1 aAl-deyab, Salem, S.1 aHalligudi, Shivappa, B.1 aVinu, Ajayan uhttps://library.ncl.res.in/content/titania-nanoparticles-stabilized-hpa-sba-15-intermolecular-hydroamination-activated-001813nas a2200217 4500008004100000022001400041245013500055210006900190260000900259300001400268490000800282520101600290100001901306700002601325700002301351700002301374700002801397700002801425700001701453856012501470 2021 eng d a1932-744700aDirect synthesis of mesoporous siliceous phosphotungstic acid and its superior catalytic activity on the cyclohexylation of phenol0 aDirect synthesis of mesoporous siliceous phosphotungstic acid an cAPR  a6723-67340 v1253 a

The synthesis of highly active and reusable mesoporous siliceous phosphotungstic acid materials (mPTA-Si) which are prepared through a simple self-assembly between phosphotungstic acid (PTA), the polymeric surfactant, and the silica precursor assisted by KCl for cyclohexylation of phenol is reported. The surface area and the acidity of these materials are tuned with a simple adjustment of PTA in the silica framework. The prepared samples exhibit mesoporous structure with a high surface area, but the structure is collapsed when the loading of PTA is high. It is established that the Keggin structure of PTA is retained on the final mPTA-Si. mPTA-Si with different loadings of PTA are employed as the catalysts for the cyclohexylation of phenol under liquid phase conditions. Among the catalysts studied, 10.0-mPTA-8.3Si calcined at 350 degrees C is found to be highly active, selective, and recyclable and offers 100% conversion of phenol with the highest selectivity for p-cyclohexylphenol (96.8%).

1 aIlbeygi, Hamid1 aSawant, Dhanashri, P.1 aRuban, Sujanya, M.1 aReshma, Kokane, S.1 aUmbarkar, Shubhangi, B.1 aHalligudi, Shivappa, B.1 aVinu, Ajayan uhttps://library.ncl.res.in/content/direct-synthesis-mesoporous-siliceous-phosphotungstic-acid-and-its-superior-catalytic