02025nas 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-002083nas a2200253   4500008004100000022001400041245011500055210006900170260005700239300001200296490000800308520123300316653001401549653001601563653001801579653001801597653001401615100001801629700001501647700001601662700001401678700001301692856012401705       2009                        eng d  a1011-372X00aCatalytic aerobic oxidation of cyclohexane and ethyl benzene over chromium-containing mesoporous organosilicas0 aCatalytic aerobic oxidation of cyclohexane and ethyl benzene ove  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcOCT  a492-4990 v1323 a<p>Chromium-containing ethane-bridged hybrid periodic mesoporous organosilicas (Cr-PMO) were synthesized using 1,2-bis(triethoxysilyl) ethane (BTEE) and tetraethyl orthosilicate (TEOS) as silica sources and alkyltrimethyl ammonium salts as surfactants by two different synthesis routes. PXRD and N(2) adsorption-desorption analysis shows that the original structure of the materials is maintained after chromium substitution while spectroscopic study proves the incorporation of chromium in the frame wall positions and show the existence of Cr(2)O(3) species in the mixed silica source (BTEE-TEOS) synthesized chromium samples. The catalytic activity of the newly developed chromium samples was evaluated in the liquid phase oxidation of cyclohexane and ethylbenzene using air as an oxidant. Further, the Cr-PMO samples exhibited better cyclohexane conversion and cyclohexanone selectivity than the conventional Cr-MCM-41 and other metal-containing MCM-41 samples. The exceptional activity of the new chromium-containing molecular sieves is attributed to the hydrophobicity of the materials and to the complementary structural features that facilitates the accessibility of substrate to the active framework chromium sites.</p>10aCr-MCM-4110aCyclohexane10aEthyl benzene10aOrganosilicas10aOxidation1 aSingh, A., P.1 aTorita, N.1 aShylesh, S.1 aIwasa, N.1 aArai, M.  uhttps://library.ncl.res.in/content/catalytic-aerobic-oxidation-cyclohexane-and-ethyl-benzene-over-chromium-containing-0