02031nas a2200241   4500008004100000022001400041245016300055210006900218260007300287300001200360490000800372520113200380653001101512653001701523653000801540653001701548653001401565100002601579700001601605700001901621700001801640856013101658       2006                        eng d  a1381-116900aCobalt-containing hexagonal mesoporous molecular sieves (Co-HMS): Synthesis, characterization and catalytic activity in the oxidation reaction of ethylbenzene0 aCobaltcontaining hexagonal mesoporous molecular sieves CoHMS Syn  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a123-1300 v2553 a<p>Cobalt-containing hexagonal mesoporous materials (Co-HMS and Co/HMS) with different cobalt content were synthesized for the first time by direct hydrothermal and post-synthesis (grafting) method. The materials were characterized in detail by X-ray diffraction, BET surface area, N-2 sorption isotherms, SEM, TEM, UV-vis and XPS techniques. Powder X-ray diffraction pattern, N2 adsorption-desorption analysis and TEM analysis show the presence of hexagonal mesoporous structure, having Type W isotherms and reveals the typical wormhole-like morphology. Spectroscopic techniques like UV-vis and XPS reveal cobalt in +2 oxidation state and tetrahedrally coordinated. Liquid phase oxidation of ethylbenzene using TBHP (70 wt%) as an oxidant shows that the catalysts are highly active, under solvent free conditions as well as under lower cobalt concentrations. Leaching studies performed by hot filtration experiments show that the cobalt catalysts prepared by hydrothermal methods are stable, while the grafted catalysts show the leaching of cobalt under the reaction conditions. (c) 2006 Elsevier B.V. All rights reserved.</p>10aCo-HMS10aethylbenzene10aHMS10ahydrothermal10aOxidation1 aBhoware, Shrikant, S.1 aShylesh, S.1 aKamble, K., R.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/cobalt-containing-hexagonal-mesoporous-molecular-sieves-co-hms-synthesis-characterization-002025nas a2200229   4500008004100000022001400041245016600055210006900221260007300290300001200363490000700375520113600382653002101518653001801539653001101557653001401568100002401582700001601606700002601622700001801648856012901666       2006                        eng d  a1387-181100aOxidation of ethyl benzene and diphenyl methane over ordered mesoporous M-MCM-41 (M = Ti, V, Cr): synthesis, characterization and structure-activity correlations0 aOxidation of ethyl benzene and diphenyl methane over ordered mes  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT  a154-1630 v953 a<p>Transition metals (M = Ti, V, Cr) were incorporated into the MCM-41 framework by surfactant-assisted direct hydrothermal (DHT) methods and were characterized in detail by XRD, N-2 adsorption-desorption, TG-DTG/DTA, SEM/TEM, DR UV-Vis, XPS and EPR. The structural regularity as well as the textural properties of the M-MCM-41 materials was confirmed by XRD, TEM and adsorption-desorption techniques. Nature of metal species and the percentage of framework as well as extra framework metal sites in the MCM-41 matrix are discussed in detail by various spectroscopic techniques. The catalytic activity as well as the selectivity of the M-MCM-41 catalysts were explored in the one-step liquid-phase oxidation reaction of ethyl benzene and diphenyl methane. Reaction data showed that the oxidation activity is more when H2O2 was used an oxidant, acetonitrile as solvent and V-MCM-41 as catalyst. However, the selectivity towards the desired keto derivatives (ethyl benzene to acetophenone and diphenyl methane to benzophenone) follows the order, Ti-MCM-41 &gt; V-MCM-41 &gt; Cr-MCM-41. (c) 2006 Elsevier Inc. All rights reserved.</p>10adiphenyl methane10aEthyl benzene10aMCM-4110aOxidation1 aJha, Ratnesh, Kumar1 aShylesh, S.1 aBhoware, Shrikant, S.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/oxidation-ethyl-benzene-and-diphenyl-methane-over-ordered-mesoporous-m-mcm-41-m-ti-v-cr-002547nas a2200205   4500008004100000022001400041245014100055210006900196260007300265300001200338490000800350520173500358653001402093653001802107653003202125653001802157100002602175700001802201856012202219       2007                        eng d  a1381-116900aCharacterization and catalytic activity of cobalt containing MCM-41 prepared by direct hydrothermal, grafting and immobilization methods0 aCharacterization and catalytic activity of cobalt containing MCM  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a118-1300 v2663 a<p>{Cobalt containing hexagonal mesoporous molecular sieves (MCM-41) were prepared by different methods viz., direct hydrothermal synthesis, grafting and immobilization. The calcined material was characterized by various spectroscopic tools such as powder X-ray diffraction (XRD), N-2 adsorption-desorption isotherms, Fourier transformed infra-red (Fr-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), diffuse reflectance UV-vis and X-ray photoelectron spectroscopy (XPS). The XRD patterns show the highly intense (100) reflection peak in the range 2-3 degrees (2 theta angle), characteristic of mesoporous material. Higher order reflection peaks suggest highly ordered mesoporous structure. N2 adsorption-desorption isotherms are of type IV according to IUPAC classification and the steep rise in the isotherms in the narrow range 3.5-4.5 of relative pressure (P/P-0) is due to the condensation of N-2 gas molecules in the pores (characteristic of mesoporous structure). In FT-IR increase in the intensity of band at 960 cm(-1) with the increase of the cobalt content in Co-MCM-41 samples indicate the incorporation of cobalt ions in the framework of MCM-41. SEM and TEM reveal spherical morphology for the cobalt substituted MCM-41. UV-vis spectra demonstrate the characteristic features of framework and extraframework cobalt in MCM-41. Cobalt is in +2 oxidation state as evidenced from UV-vis and XPS. The catalysts were tested for the side chain oxidation of ethylbenzene using 70 wt.% tert-butyl hydrogen peroxide as an oxidant with and without the use of solvent. Solvents have effect in the catalytic activity and selectivity. In the absence of solvent, substituted cobalt [</p>10a2-butanol10acyclohexanone10aMesoporous molecular sieves10aMPV reduction1 aBhoware, Shrikant, S.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/characterization-and-catalytic-activity-cobalt-containing-mcm-41-prepared-direct-001670nas a2200229   4500008004100000022001400041245010400055210006900159260005700228300001200285490000800297520087400305653002001179653000801199653001901207653001101226653000801237100002601245700001901271700001801290856013201308       2009                        eng d  a1011-372X00aCatalytic activity of cobalt containing MCM-41 and HMS in liquid phase oxidation of diphenylmethane0 aCatalytic activity of cobalt containing MCM41 and HMS in liquid   a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcNOV  a106-1110 v1333 a<p>Cobalt containing MCM-41 and HMS were synthesized by direct hydrothermal (DHT) and post synthesis methods (grafting and immobilization). The catalytic activity of these materials was investigated in the liquid phase oxidation of diphenylmethane at 80 A degrees C with TBHP (70 wt%) as oxidant. Comparative study of cobalt containing MCM-41 and HMS was carried out to reveal the catalytic performance of framework, extraframework and immobilized cobalt species. The role of the solvent in the performance of catalyst was examined with different polar and non polar solvents. Oxidation of diphenylmethane in solvent free media (under similar reaction conditions) shows formation of hydroxy derivatives of benzophenone in addition to main product (benzophenone). Hundred percent selectivity to benzophenone was obtained when the reaction was carried out in solvent.</p>10adiphenylmethane10aHMS10aImmobilization10aMCM-4110aXRD1 aBhoware, Shrikant, S.1 aKamble, K., R.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/catalytic-activity-cobalt-containing-mcm-41-and-hms-liquid-phase-oxidation-diphenylmethane-0