02150nas a2200337   4500008004100000022001400041245009600055210006900151260007700220300001400297490000600311520104700317653001101364653002801375653001501403653002001418653001301438100001901451700001501470700001801485700001801503700002101521700001601542700002001558700002301578700002801601700001601629700001401645700002401659856012901683       2012                        eng d  a1867-388000aOne-pot sol-gel preparation for efficient cobalt-molybdenum-titania hydrotreating catalysts0 aOnepot solgel preparation for efficient cobaltmolybdenumtitania   aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcDEC  a2112-21200 v43 a<p>Titania-based hydrodesulfurization catalysts were prepared by using a one-pot solgel method with the titanium peroxo complex as titanium precursor and molybdenum and cobalt precursors dissolved in the aqueous hydrogen peroxide solution used during synthesis. Catalysts with MoO3 loadings varying from 5 to 40 wt?% and a Co/Mo atomic ratio of 0.5 were prepared. Solids with molybdenum loadings below 20 wt?% MoO3 demonstrated poor hydrodesulfurization activity for the model compound thiophene. This was attributed to the presence of a large amount of embedded cobalt and molybdenum species in the titania matrix. A significant increase in the catalytic activity was observed for solids containing 20 and 25 wt?% of MoO3 on which active species appeared to be accessible on the titania surface. Furthermore, the highest conversion obtained on these solgel solids was superior to the highest conversion obtained on reference catalysts prepared through the impregnation of ammonium heptamolybdate and cobalt nitrate on commercial titania.</p>10acobalt10aheterogeneous catalysis10aMolybdenum10asol-gel process10atitanium1 aNguyen, D., L.1 aGillot, S.1 aSouza, D., O.1 aBlanchard, P.1 aLamonier, Carole1 aBerrier, E.1 aKotbagi, T., V.1 aDongare, Mohan, K.1 aUmbarkar, Shubhangi, B.1 aCristol, S.1 aPayen, E.1 aLancelot, Christine  uhttps://library.ncl.res.in/content/one-pot-sol-gel-preparation-efficient-cobalt-molybdenum-titania-hydrotreating-catalysts-002485nas a2200241   4500008004100000022001400041245014800055210006900203260007700272300001400349490000600363520154400369653002901913653002801942653001501970653001201985653002201997100002402019700002402043700002802067700002302095856012502118       2013                        eng d  a1867-388000aIsolation, characterization, and identification of catalytically active species in the MoO3/SiO2 catalyst during solid acid catalyzed reactions0 aIsolation characterization and identification of catalytically a  aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcJUN  a1531-15370 v53 a<p>We report the isolation, characterization, and identification of the catalytically active species formed during various acid-catalyzed reactions if silica-supported MoO3 was used as a catalyst. We have reported previously the synthesis and extensive characterization of the silica-supported MoO3 catalyst prepared by the sol-gel process with ammonium heptamolybdate and ethyl silicate-40 as molybdenum and silica precursors, respectively. The TEM images showed uniformly distributed MoO3 nanoparticles on the high-surface area mesoporous silica support and high acidity (0.9mmolg-1) by using temperature-programmed desorption of ammonia (NH3-TPD) analysis. This catalyst has already shown high activity for various acid-catalyzed reactions. To understand the nature of catalytically active species formed during the reaction, the liquid-phase esterification of acetic acid and ethanol was studied as a probe reaction with very high acid conversion (83%) in 8h. During esterification, the reaction mixture turned blue, which indicated a change in the nature of the catalyst under reaction conditions. These catalytically active species formed in the reaction mixture were isolated and extensively characterized by using FTIR, Raman, powder XRD, BET surface area, NH3-TPD, energy dispersive X-ray, and TEM analysis. The characterization results revealed the insitu formation of silicomolybdic acid on the silica surface in the presence of water, which acts as catalytically active species responsible for the acid-catalyzed reactions.</p>10aesterification reactions10aheterogeneous catalysis10aMolybdenum10asilicon10asol-gel processes1 aKotbagi, Trupti, V.1 aBiradar, Ankush, V.1 aUmbarkar, Shubhangi, B.1 aDongare, Mohan, K.  uhttps://library.ncl.res.in/content/isolation-characterization-and-identification-catalytically-active-species-moo3sio2-002075nas a2200301   4500008004100000022001400041245008700055210006900142260006900211300001200280490000800292520106000300653002001360653001601380653001501396653001401411653001301425100002401438700002301462700002601485700002301511700002001534700002301554700002801577700002301605700003401628856011101662       2014                        eng d  a0022-328X00aMolybdenum(VI) dioxo complexes for the epoxidation of allylic alcohols and olefins0 aMolybdenumVI dioxo complexes for the epoxidation of allylic alco  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcDEC  a271-2790 v7723 a<p>Several molybdenum(VI) dioxo complexes have been investigated as catalyst precursors for allylic alcohol epoxidation using mainly hydrogen peroxide as oxidant. All catalysts proved to be efficient and selective for the epoxidation of allylic alcohols provided the olefins were rather electron rich. Indeed, electron poor substrates could be converted selectively into the corresponding unsaturated aldehydes. A chiral dioxomolybdenum complex based on an optically pure tridentate Schiff base ligand was synthesized and characterized. Though that complex provided an efficient epoxidation catalyst for allylic alcohols and olefins, no chiral induction was observed. During the X-ray diffraction analysis, the cooling at 100 K led to the appearance of super-lattice reflections on diffraction patterns reflecting an ordering of the structure. Instead of one organometallic species observed at 298 K, three similar complexes of the same molecular structure could be observed in the asymmetric unit at 100 K. (C) 2014 Elsevier B.V. All rights reserved.</p>10aAllylic alcohol10aepoxidation10aMolybdenum10aOxidation10aPeroxide1 aPandhare, Swati, L.1 aJadhao, Rajesh, R.1 aPuranik, Vedavati, G.1 aJoshi, Pranaya, V.1 aCapet, Frederic1 aDongare, Mohan, K.1 aUmbarkar, Shubhangi, B.1 aMichon, Christophe1 aAgbossou-Niedercorn, Francine  uhttps://library.ncl.res.in/content/molybdenumvi-dioxo-complexes-epoxidation-allylic-alcohols-and-olefins-0