02083nas 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-002068nas a2200241   4500008004100000022001400041245010400055210006900159260009200228300001200320490000600332520118900338653001401527653002501541653002701566653001801593100001601611700002501627700002101652700002001673700001801693856011501711       2011                        eng d  a1941-490000aSynthesis and characterization of bifunctional ethenylene bridged mesoporous organoaluminosilicates0 aSynthesis and characterization of bifunctional ethenylene bridge  a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScAUG  a497-5020 v33 a<p>Bifunctional mesoporous organosilicas having -CH=CH- bridges and aluminium in tetrahedral coordination with tailorable pore sizes have been synthesized using a one-step templating method using cationic surfactants of different chain lengths. Unlike the conventional EtOH-HCl template extraction process, EtOH-NH(4)NO(3) was used as the surfactant-extracting medium and chemical analysis results suggest that through this procedure the mesoporous structure can be retained and dealumination can be minimized. The surfactant-extracted mesoporous solids display high surface area, pore volume and the pore size of the material varies in the range 2.6-3.6 nm, with respect to the alkyl chain length of the cationic surfactant. XRD and nitrogen physisorption studies further proved that the organosilicas are hydro thermally stable than the conventional Al-MCM-41 materials and their better stability is attributed to the thick pore walls as well as due to the presence of hydrophobic bridging ethenylene groups in the wall positions. The coupling of Al(4) with -CH=CH- bridges offer new prospects for the application of periodic mesoporous organosilicas in heterogeneous catalysis.</p>10aAluminium10aCationic Surfactants10aHydrothermal stability10aOrganosilicas1 aShylesh, S.1 aKapoor, Mahendra, P.1 aJuneja, Lekh, R.1 aSrilakshmi, Ch.1 aSingh, A., P.  uhttps://library.ncl.res.in/content/synthesis-and-characterization-bifunctional-ethenylene-bridged-mesoporous-0