02372nas a2200217 4500008004100000022001400041245011200055210006900167260009500236300000900331490000800340520152800348653003001876653002501906653001901931653001301950100002201963700001701985700002802002856012402030 2005 eng d a0021-951700aZirconia-supported 12-tungstophosphoric acid as a solid catalyst for the synthesis of linear alkyl benzenes0 aZirconiasupported 12tungstophosphoric acid as a solid catalyst f a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcAPR a1-100 v2313 a

The liquid-phase alkylation of benzene with 1-octene and 1-dodecene was investigated with zirconia-supported 12-tungstophosphoric acid (TPA) as catalysts. We prepared the catalysts, with different TPA loading (5-20 wt% calcined at 750 degrees C) and calcination temperatures (15 wt% calcined from 650 to 850 degrees C), by suspending hydrous zirconia in a methanol solution of TPA, followed by drying and calcination. These catalysts were characterized by X-ray diffraction, DTG-DTA, FTIR pyridine adsorption, NH3-TPD, and P-31, MAS NMR spectroscopy measurements. The catalyst with optimum TPA loading (15%) and calcination temperature (750 degrees C) was prepared in different solvents and characterized by P-31 MAS NMR spectroscopy. The XRD results indicate that TPA stabilizes the tetragonal phase of zirconia. The catalysts show both Bronsted and Lewis acidity, and 15% TPA on zirconia calcined at 750 degrees C shows the highest acidity. P-31 MAS NMR spectra show two types of phosphorous species: one is the Keggin unit and the other is the decomposition product of TPA. The relative amount of each depends on TPA loading, calcination temperature, and the solvent used for the catalyst preparation. Under reaction conditions of 84 degrees C and a benzene/1-olefin molar ratio of 10 (time 1 h), the most active catalyst, 15% TPA, calcined at 750 degrees C, gave more than 98% olefin conversion with selectivity for 2-phenyl octane (53.5%) and 2-phenyl dodecane (47%). (c) 2004 Elsevier Inc. All rights reserved.

10a12-tungstophosphoric acid10alinear alkyl benzene10asolvent effect10aZirconia1 aDevassy, Biju, M.1 aLefebvre, F.1 aHalligudi, Shivaraj, B. uhttps://library.ncl.res.in/content/zirconia-supported-12-tungstophosphoric-acid-solid-catalyst-synthesis-linear-alkyl-001457nas a2200205 4500008004100000022001400041245006500055210006500120260008600185300001800271490000700289520069400296653001100990653003401001653001901035653004301054653003201097100002301129856009901152 2009 eng d a0003-271900aStudies of anion transport through supported liquid membrane0 aStudies of anion transport through supported liquid membrane a325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USAbTAYLOR & FRANCIS INCcNOV aPII 9167699490 v423 a

Transport studies of anions were investigated through cellulose triacetate supported liquid membrane. The experimental variables explored were concentration of anions, sodium hydroxide, and stirring speed. The two-channel membrane system has been explored for the transport of carbonate ions from source to receiving phases. Carbonate ions are selectively transported through the cellulose triacetate supported liquid membrane in comparison with that of nitrate and sulfate. Sulfate and nitrate anions are strongly held in the cellulose triacetate membrane, and then stripped out later. Carbonate ions are loosely bound to the cellulose triacetate membrane and stripped out earlier.

10aAnions10acellulose triacetate membrane10asolvent effect10astability of supported liquid membrane10atwo-channel membrane system1 aGaikwad, Abaji, G. uhttps://library.ncl.res.in/content/studies-anion-transport-through-supported-liquid-membrane-001462nas a2200217 4500008004100000022001400041245010200055210006900157260006700226300001400293490000800307520068000315653001000995653000801005653002401013653002701037653001901064100001501083700001601098856013001114 2010 eng d a0020-760800aEffect of solvents having different dielectric constants on reactivity: a conceptual DFT approach0 aEffect of solvents having different dielectric constants on reac a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcAUG a1642-16470 v1103 a

Conceptual density functional theory is exploited to understand the reactivity in a medium of solvents with increasing dielectric constants. Aprotic as well as protic solvents are used for this study. It is found that the global parameters, such as chemical potential and hardness, decrease from gas phase to solvent phase with increasing dielectric constant. However, it is observed that the Fukui functions of the reactive atoms increase significantly with the dielectric constants of the aprotic solvents while for the protic solvents the variation of the reactivity indices is insignificant. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 110: 1642-1647, 2010

10aCOSMO10aDFT10adielectric constant10aReactivity descriptors10asolvent effect1 aKar, Rahul1 aPal, Sourav uhttps://library.ncl.res.in/content/effect-solvents-having-different-dielectric-constants-reactivity-conceptual-dft-approach-002902nas a2200289 4500008004100000022001400041245012300055210006900178260000800247300001100255490000800266520195400274653001802228653000802246653003102254653001302285653002902298653001902327100001902346700002202365700001902387700002302406700001602429700001902445700001802464856013002482 2025 eng d a1385-894700aFacet dependence for solvent-modulated proton-coupled electron transfer in furfural acetalization on Pd nanostructures0 aFacet dependence for solventmodulated protoncoupled electron tra cJUN a1631590 v5143 a

Furfural dialkyl acetals prepared via acetalization reaction of furfural and alcohols are promising biofuels. Using defined experiments and density functional theory (DFT) simulations, the structure-dependent activity and selectivity for furfural acetalization reaction in the presence of alcohols (methanol, ethanol, propanol and butanol) as solvents was studied over well-defined supported Pd nanostructures (octahedra (111), cubes (100) and spheres (both (111) and (100)). Pd cubes supported over TiO2 in the presence of ethanol as a solvent (at 303 K and balloon pressure H-2) exhibited 78 % conversion and 100 % selectivity for furfural diethyl acetal product in a short time (similar to 180 min). In contrast, Pd octahedra (111) and Pd spheres showed low conversions (18 % and 6 %) at the same reaction conditions. Interestingly, when used as a solvent, methanol showed the highest conversion (90 %) and selectivity (100 %) for furfural acetalization over Pd cubes. DFT simulations provided mechanistic insight into the reactivity of the two different Pd facets (111) and (100) in the presence of alcohol molecules towards furfural acetalization reaction. A three-step reaction mechanism was proposed for furfural acetalization with alcohols: (i) alcohol hydroxyl-dehydrogenation (ii) hydrogenation of furfural carbonyl oxygen, and (iii) formation of hemiacetal product. For all three steps, Pd (100) exhibited low activation barriers (51.6, 26.7 and 76.2 kJ/mol) compared to Pd (111) surface (78.6, 35.8 and 92.2 kJ/mol) in the presence of ethanol. The activation barriers for the above steps were further reduced to 47.8, 23.9 and 64.6 kJ/mol on Pd (100) in the presence of methanol, explaining the experimental high reactivity aided by methanol. DFT calculations elucidated the role of the hydrogen bonding network between the solvent molecules and adsorbate, enabling proton-coupled electron transfer for accelerated reactions.

10aAcetalization10aDFT10afacet-dependent reactivity10afurfural10aFurfural dialkyl acetals10asolvent effect1 aPorwal, Govind1 aDandekar, Pallavi1 aGorai, Twinkle1 aKhan, Tuhin, Suvra1 aHaider, Ali1 aGupta, Shelaka1 aVinod, C., P. uhttps://library.ncl.res.in/content/facet-dependence-solvent-modulated-proton-coupled-electron-transfer-furfural-acetalization