02623nas a2200301   4500008004100000022001400041245014300055210006900198260009500267300001200362490000800374520152800382653002701910653001201937653001701949653001801966653003001984653001802014653001202032653001202044100001802056700002102074700002602095700003002121700001602151700002602167856012802193       2005                        eng d  a0021-951700aOxidative dehydrogenation of ethylbenzene over vanadia-alumina catalysts in the presence of nitrous oxide: structure-activity relationship0 aOxidative dehydrogenation of ethylbenzene over vanadiaalumina ca  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcMAR  a484-4920 v2303 a<p>A series of vanadia-alumina catalysts with different vanadia contents were prepared by a wet impregnation method. The influence of the local structure of vanadia in these catalysts on the oxidative dehydrogenation of ethylbenzene with nitrous oxide was investigated. The use of N2O as a co-feed remarkably enhanced the styrene yield compared with the use of N-2. Characterization of these vanadia catalysts by XRD, FTIR, UV-vis, TPR, XPS, and V-51 NMR techniques suggests that the nature of the VOx species depends on the vanadia loading: the predominant species are monomeric vanadia at lower loadings, two-dimensional polyvanadates at intermediate loadings, and bulk-like V2O5 and AlVO4 at higher loadings. The rate of oxidative dehydrogenation (ODH) of ethylbenzene per vanadium atom increases with vanadia loading and reaches a maximum at 10 wt%, the loading at which the surface predominantly contains polyvanadate species. The observed variation in the selectivity of products with vanadium loading indicates that the monomeric V5+ species favors dehydrogenation, whereas bulk-like V2O5 preferentially participates in the dealkylation of ethylbenzene. The vanadium species remains at a higher oxidation state in the presence of N2O, leading to a higher styrene yield. than in a N-2 atmosphere. The ODH turnover rates increased with decreasing energy of the absorption edge in the UV-vis spectrum, at low VOx coverages of less than one monolayer on the Al2O3 surface. (c) 2005 Elsevier Inc. All rights reserved.</p>10aabsorption edge energy10aAlumina10aethylbenzene10aNitrous oxide10aoxidative dehydrogenation10apolyvanadates10astyrene10avanadia1 aShiju, N., R.1 aAnilkumar, Mettu1 aMirajkar, Subhash, P.1 aGopinath, Chinnakonda, S.1 aRao, B., S.1 aSatyanarayana, C., V.  uhttps://library.ncl.res.in/content/oxidative-dehydrogenation-ethylbenzene-over-vanadia-alumina-catalysts-presence-nitrous-002179nas a2200217   4500008004100000022001400041245014600055210006900201260007300270300001200343490000700355520136100362653001601723653002701739653001201766653001001778653001301788100001601801700001801817856012601835       2006                        eng d  a1387-181100aVanadium-containing ethane-silica hybrid periodic mesoporous organosilicas: synthesis, structural characterization and catalytic applications0 aVanadiumcontaining ethanesilica hybrid periodic mesoporous organ  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP  a127-1380 v943 a<p>Vanadium-containing ethane-silica hybrid mesoporous silsesquioxane materials (V-HMM) with uniform hexagonal arrangement were prepared using C-18-, C-16- and C-14-alkyl trimethyl ammonium (ATMA) surfactants under basic conditions. The materials were characterized by PXRD, N-2 adsorption-desorption, UV-Visible spectroscopy, Raman, Si-29, C-13 and V-51 solid-state MAS NMR, TEM and SEM techniques. The characterization techniques revealed that the structural ordering, morphology as well as the percentage of metal incorporation depends strongly on the hydrophobic chain length of the surfactant. PXRD, electron microscopy and N-2 adsorptiondesorption analysis confirmed that the original hexagonal structure of the material is maintained after vanadium substitution. UV-Visible, V-51 NMR and Raman analysis certified that vanadium exists in a highly dispersed state and had tetrahedral coordination with the support surface. Liquid-phase epoxidation reaction of styrene using aqueous H2O2 and TBHP as oxidants, showed that the hybrid materials were highly active and more stable than conventional vanadosilicates. The high catalytic activity and improved epoxide selectivity of the V-HMM samples is related to the more hydrophobic environment inside the pore channels than the silica channels in V-MCM-41. (c) 2006 Elsevier Inc. All rights reserved.</p>10aepoxidation10aorgano vanadosilicates10astyrene10aV-HMM10aV-MCM-411 aShylesh, S.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/vanadium-containing-ethane-silica-hybrid-periodic-mesoporous-organosilicas-synthesis-001816nas a2200289   4500008004100000022001400041245012100055210006900176260007300245300001400318490000600332520082400338653001401162653001401176653001401190653001801204653001301222653001601235653001201251653001801263653003301281100002601314700001401340700002501354700001801379856012901397       2007                        eng d  a1566-736700aSupported copper oxide as a highly active/selective catalyst for the epoxidation of styrene by TBHP to styrene oxide0 aSupported copper oxide as a highly activeselective catalyst for   aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT  a1556-15600 v83 a<p>Liquid phase epoxidation of styrene by anhydrous and aqueous TBHP to styrene oxide has been studied under reflux, using different supported CuO (viz. Cuo/Si-MCM-41, CuO/Al2O3, CuO/Ga2O3 and CuO/In2O3) as easily separable and reusable heterogeneous catalysts. The CuO/Ga2O3 catalyst showed the best performance in the epoxidation by aqueous TBHP. The CuO supported on In2O3 or Si-MCM-41 also showed very good performance in the epoxidation but only by anhydrous TBHP. However, the CUO/SiO2 catalyst, however, showed very good performance in the epoxidation by both the anhydrous and aqueous TBHP. Influence of the reaction conditions (temperature, time and TBHP/styrene ratio) on the epoxidation by aqueous TBHP over the best catalyst (CuO/Ga2O3) has been investigated. (C) 2007 Elsevier B.V. All rights reserved.</p>10aCuO/Al2O310aCuO/Ga2O310aCuO/In2O310aCuo/Si-MCM-4110aCuO/SiO210aepoxidation10astyrene10aStyrene oxide10atertiary butyl hydroperoxide1 aChoudhary, Vasant, R.1 aJha, Rani1 aChaudhari, Nitin, K.1 aJana, Prabhas  uhttps://library.ncl.res.in/content/supported-copper-oxide-highly-activeselective-catalyst-epoxidation-styrene-tbhp-styrene-001293nas a2200253   4500008004100000022001400041245016900055210006900224260007300293300001200366490000700378520038500385653000800770653001600778653000900794653000800803653001200811653001800823653000900841100002600850700001400876700001800890856013100908       2008                        eng d  a1566-736700aSelective epoxidation of styrene to styrene oxide by TBHP using simple transition metal oxides (NiO, CoO or MoO3) as highly active environmentally-friendly catalyst0 aSelective epoxidation of styrene to styrene oxide by TBHP using   aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV  a205-2070 v103 a<p>Simple transition metal oxides, such as NiO, CoO or MoO3, etc. show high catalytic activity for the selective epoxidation of styrene to styrene oxide by TBHP. The order of choice for different transition metal oxides for epoxidation is NiO &gt; CoO &gt; MoO3 &gt; Cr2O3 &gt; Fe2O3 &gt; ZnO &gt;= U3O8 &gt;&gt; TiO2 &gt;&gt; MnO2. (C) 2008 Elsevier B.V. All rights reserved.</p>10aCoO10aepoxidation10aMoO310aNiO10astyrene10aStyrene oxide10aTBHP1 aChoudhary, Vasant, R.1 aJha, Rani1 aJana, Prabhas  uhttps://library.ncl.res.in/content/selective-epoxidation-styrene-styrene-oxide-tbhp-using-simple-transition-metal-oxides-nio-003557nas a2200253   4500008004100000022001400041245010900055210006900164260007500233300001400308490000700322520266100329653001702990653001903007653001603026653002503042653002403067653001403091653001203105653001803117100002603135700002203161856012003183       2009                        eng d  a1022-552800aSupported nano-gold catalysts for epoxidation of styrene and oxidation of benzyl alcohol to benzaldehyde0 aSupported nanogold catalysts for epoxidation of styrene and oxid  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGER/PLENUM PUBLISHERScNOV  a1677-16870 v523 a<p>Nano-gold particles supported on different alkaline earth oxides (viz. MgO, CaO, BaO and SrO), Gr. IIIa metal oxides (viz. Al(2)O(3), Ga(2)O(3), In(2)O(3) and Tl(2)O(3)), transition metal oxides (viz. TiO(2), Cr(2)O(3), MnO(2), Fe(2)O(3), CoO(x), NiO, CuO, ZnO, Y(2)O(3) and ZrO(2)), rare earth metal oxides (viz. La(2)O(3), Ce(2)O(3), Nd(2)O(3), Sm(2)O(3), Eu(2)O(3), Tb(2)O(3), Er(2)O(3) and Yb(2)O(3)) and U(3)O(8) [all prepared by depositing gold on corresponding metal oxide support by deposition precipitation (DP) and/or homogeneous deposition precipitation (HDP) method] were evaluated for their catalytic performance in the liquid phase epoxidation of styrene by tert-butyl hydroperoxide (TBHP) to styrene oxide and also in the solvent-free benzyl alcohol-to-benzaldehyde oxidation (by molecular oxygen or TBHP) reactions. For the epoxidation, the catalytic performance (styrene oxide yield) of the most promising nano-gold catalysts prepared by the HDP method was in the following order: Au/MgO &gt; Au/Tl(2)O(3) &gt; Au/Yb(2)O(3) &gt; Au/Tb(2)O(3) &gt; Au/CaO (or TiO(2)). However, for the oxidation of benzyl alcohol to benzaldehyde by molecular oxygen, the order of choice for the most promising catalysts (based on benzaldehyde yield) was Au/U(3)O(8) &gt; Au/Al(2)O(3) &gt; Au/ZrO(2) &gt; Au/MgO. Whereas, when TBHP was used as an oxidizing agent for the benzyl alcohol oxidation, the order of choice for the most promising catalysts was Au/U(3)O(8) &gt; Au/MgO &gt; Au/TiO(2) &gt; Au/ZrO(2) &gt; Au/Al(2)O(3). The catalytic performance of a particular supported nano-gold catalyst was thus found to depend on the reaction catalysed by them. Moreover, it is strongly influenced by a number of catalyst parameters, such as the metal oxide support, the method of gold depositon on the support, the gold loading and also on the catalyst calcination temperature. Nano-gold particles-support interactions seem to play an important role in controlling the deposition of gold ( amount of gold deposited and size and morphology of gold particles), formation of different surface gold species (Au(0), Au(1+) and Au(3+)) and electronic properties of gold particles and, consequently, control the catalytic performance (both the activity and selectivity) of the supported nano-gold catalysts in the reactions. The nano-gold catalysts prepared by the HDP method showed much better catalytic performance than those prepared by the DP, coprecipitation or impregnation method; in general, the HDP method provided supported gold catalysts with much higher gold loading and/or smaller size gold particles than that achieved by the DP and other methods.</p>10aBenzaldehyde10aBenzyl alcohol10aepoxidation10aMetal oxide supports10aNano-gold catalysts10aOxidation10astyrene10aStyrene oxide1 aChoudhary, Vasant, R.1 aDumbre, Deepa, K.  uhttps://library.ncl.res.in/content/supported-nano-gold-catalysts-epoxidation-styrene-and-oxidation-benzyl-alcohol-001350nas a2200253   4500008004100000022001400041245010500055210006900160260005600229300001000285490000700295520048400302653001200786653001600798653001300814653001200827653001800839100002000857700001900877700002200896700002500918700002100943856013200964       2010                        eng d  a1509-811700aKinetics studies and mechanism evolution of the epoxidation of styrene over nanoporous Au doped TS-10 aKinetics studies and mechanism evolution of the epoxidation of s  aSOLIPSKA 14A-1, 02-482 WARSAW, POLANDbVERSITAcJAN  a72-780 v123 a<p>{A kinetic investigation of the slurry phase epoxidation of styrene with hydrogen peroxide has been carried out, for the first time, over nanoporous Au doped TS-1 catalyst, in a batch reactor, in the temperature range of 313-333 K. It was found that product selectivity and the rate of reaction are greatly influenced by concentrations of styrene and hydrogen peroxide. Kinetics studies reveal that the mechanism of the reaction is of the ``Redox'' type. The rate equation</p>10aAu/TS-110aepoxidation10akinetics10astyrene10aStyrene oxide1 aSaxena, Samidha1 aDwivedi, Reena1 aBhadauria, Sheenu1 aChumbhale, Vilas, R.1 aPrasad, Rajendra  uhttps://library.ncl.res.in/content/kinetics-studies-and-mechanism-evolution-epoxidation-styrene-over-nanoporous-au-doped-ts-1-0