01377nas a2200217   4500008004100000020002200041022001400063245007100077210006600148260009900214300001400313490000800327520064200335100002000977700001700997700001001014700001201024700001201036700001101048856010001059       2007                        eng d  a978-0-444-53068-4  a0167-299100aCe-Al-MCM-41: an efficient catalyst for Mukaiyama-Michael reaction0 aCeAlMCM41 an efficient catalyst for MukaiyamaMichael reaction  aSara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, NetherlandsbElsevier Science BVcAUG  a1161-11660 v1703 a<p>The activity of cerium containing Al-MCM-41 mesoporous materials has been studied for carbon-carbon bond formation reaction like Mukaiyama-Michael reaction under mild liquid phase conditions. The catalysts were synthesized by hydrothermal method at 383 K for 24-36 h in Teflon-lined autoclave and characterized thoroughly by XRD, UV-VIS, TEM, EPR, XPS, (27)Al NMR, NH(3)-TPD, pyridine-IR and AAS in order to obtain well-ordered M41S type materials. The Mukiayama-Michael reactions between silyl enol ether and alpha,beta-unsaturated ketones give Michael product in very good yields (100% selectivity). The catalysts were reusable.</p>1 aKalita, Pranjal1 aKumar, Rajiv1 aXu, R1 aGao, Z.1 aChen, J1 aYan, W  uhttps://library.ncl.res.in/content/ce-al-mcm-41-efficient-catalyst-mukaiyama-michael-reaction-001492nas a2200217   4500008004100000020002200041022001400063245011200077210006900189260009900258300001400357490000800371520069100379100001701070700001801087700001001105700001201115700001201127700001101139856012401150       2007                        eng d  a978-0-444-53068-4  a0167-299100aChemoselective alkane oxidations by reactive superoxovanadium(V) species in vanadosilicate molecular sieves0 aChemoselective alkane oxidations by reactive superoxovanadiumV s  aSara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, NetherlandsbElsevier Science BVcAUG  a1205-12120 v1703 a<p>Unlike their titanium analogs, vanadosilicate molecular sieves catalyze the oxidation of the terminal (primary) C-H bonds in paraffins. This dissimilarity is attributed to differences in the type of reactive superoxo species generated on contact with oxidant. The latter were identified and characterized by in situ EPR and DRUV-vis spectroscopic techniques. By a suitable choice of silicate structure (VS-1 or V-MCM-41), solvent and oxidant (H(2)O(2), tert.-butyl hydroperoxide or H(2)+O2()), the V-O bond covalency and mode of O-O bond cleavage in the oxo-species and thereby, the chemoselectivity in the oxidation of the terminal carbon atoms in paraffins could be controlled.</p>1 aSrinivas, D.1 aRatnasamy, P.1 aXu, R1 aGao, Z.1 aChen, J1 aYan, W  uhttps://library.ncl.res.in/content/chemoselective-alkane-oxidations-reactive-superoxovanadiumv-species-vanadosilicate-001809nas a2200241   4500008004100000020002200041022001400063245014400077210006900221260009900290300001400389490000800403520090400411100001601315700002401331700001901355700001801374700001001392700001201402700001201414700001101426856013001437       2007                        eng d  a978-0-444-53068-4  a0167-299100aEthane bridged hybrid mesoporous silsesquioxanes with sulfonic acid functionalities: synthesis, characterization and catalytic applications0 aEthane bridged hybrid mesoporous silsesquioxanes with sulfonic a  aSara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, NetherlandsbElsevier Science BVcAUG  a1899-19040 v1703 a<p>Periodic mesoporous organosilicas having -CH(2)-CH(2)- groups in the framewall positions and sulfonic acid groups in the pore channels were prepared using 1,2-bis(triethoxysilyl) ethane, 3-mercaptopropyltriethoxysilane and cetyltrimethylammonium surfactant, under basic conditions, by a one-pot synthesis method. XRD, N(2) sorption isotherm and TEM analysis revealed that the mesoporous structural ordering is retained after the functionalization of organic groups while solid-state NMR techniques like (13)C CP MAS NMR and (29)Si MAS NMR show the presence of sulfonic acid groups and the stability of the mesoporous framework with integrated ethane moieties as bridging groups. The hybrid material was more active, selective and stable than the conventional sulfonic acid containing mesoporous catalysts in the Claisen-Schmidt condensation of acetophenone with benzaldehyde to form chalcone.</p>1 aShylesh, S.1 aSamuel, Prinson, P.1 aParischa, Renu1 aSingh, A., P.1 aXu, R1 aGao, Z.1 aChen, J1 aYan, W  uhttps://library.ncl.res.in/content/ethane-bridged-hybrid-mesoporous-silsesquioxanes-sulfonic-acid-functionalities-synthesis-001734nas a2200241   4500008004100000020002200041022001400063245006700077210006600144260009900210300001400309490000800323520094300331100001801274700001601292700002101308700002001329700001001349700001201359700001201371700001101383856009801394       2007                        eng d  a978-0-444-53068-4  a0167-299100aImmobilization of Ntn hydrolases on APTES fuctionalized SBA-150 aImmobilization of Ntn hydrolases on APTES fuctionalized SBA15  aSara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, NetherlandsbElsevier Science BVcAUG  a1891-18980 v1703 a<p>APTES Functionalized mesoporous silica SBA-15 molecular sieves have been prepared and used for immobilization of Penicillin G acylase. Physico chemical characterization was done by nitrogen adsorption, powder XRD and TEM methods to understand the nature of immobilized PGA enzyme. XRD data indicate a good mesoscopic order. The characteristic hexagonal features of SBA-15 were maintained in PGA immobilized SBA-15 samples. Incorporation of PGA does not affect the original pore structure of the parent SBA-15. The adsorption of PGA on SBA-15 from buffered solutions with a pH value, 7.8 has been studied as a model protein adsorption system. The maximum activity of the immobilized enzyme was observed at pH 7.8, slightly below the isoelectric point of the enzyme. The loading capacity of immobilized PGA is 34 mg protein per 0.5 g of SBA-15. The stability of Penicillin G acylase was enhanced by the physical entrapment in SBA-15.</p>1 aShah, Pallavi1 aSridevi, N.1 aPrabhune, Asmita1 aRamaswamy, Veda1 aXu, R1 aGao, Z.1 aChen, J1 aYan, W  uhttps://library.ncl.res.in/content/immobilization-ntn-hydrolases-aptes-fuctionalized-sba-15-002183nas a2200241   4500008004100000020002200041022001400063245011400077210006900191260005500260300001200315490000800327520135800335100002001693700002201713700001801735700001401753700001001767700001201777700001201789700001101801856012901812       2007                        eng d  a978-0-444-53068-4  a0167-299100aSynthesis and characterization of value added catalysts zeolite beta using environmentally detrimental flyash0 aSynthesis and characterization of value added catalysts zeolite   aBeijing, Peoples R ChinabElsevier Science BVcAUG  a438-4430 v1703 a<p>Fly ash is a major byproduct of Thermal power plant, which makes a lot of pollution to the environment due to its fineness. When a large amount of fly ash is dumped in the places near to power plants, it mixes in all segment of environment like water, air as well as soil. Though it can be utilized for different useful purposes, due to the lack of technical knowledge about how and proper motivation, no progress has been made in its utilization. It has been demonstrated that the fly ash can be used for making a value added catalyst zeolite beta by using simple and low cost process. In the present paper it is demonstrated that the fly ash can be used as a source of silica and alumina in the synthesis of value added catalyst zeolite beta. Moreover, the influence of different silica sources such as tetraethylortho silicate, silica sol and fumed silica on the physiochemical characteristics of well crystallized zeolite beta was also studied. The detailed characterization was carried out by using powder XRD, (27)Al and (29)Si MAS NMR, chemical analysis and low temperature nitrogen adsorption. Based on the data obtained from various systems containing different silica source, fumed silica is found to be most efficient source materials and showed superiority in the uniformity of aluminum distribution and possesses higher surface area.</p>1 aKasture, M., W.1 aBokade, Vijay, V.1 aJoshi, P., N.1 aKumar, R.1 aXu, R1 aGao, Z.1 aChen, J1 aYan, W  uhttps://library.ncl.res.in/content/synthesis-and-characterization-value-added-catalysts-zeolite-beta-using-environmentally-001600nas a2200205   4500008004100000020002200041022001400063245010500077210006900182260009900251300001400350490000800364520082200372100002801194700001101222700001201233700001301245700001201258856012401270       2007                        eng d  a978-0-444-53068-4  a0167-299100aTungstophosphoric acid and zirconia supported on mesoporous silica catalyst in veratrole acetylation0 aTungstophosphoric acid and zirconia supported on mesoporous sili  aSara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, NetherlandsbElsevier Science BVcAUG  a1325-13300 v1703 a<p>Tungstophosphoric acid (TPA) over zirconia dispersed uniformly in mesoporous silica (MS) channels of MCM-41 and MCM-48 was synthesised and tested for its catalytic activity in veratrole acetylation. Catalysts with different TPA loadings (5 to 50 wt.%) on 22.4 wt.% ZrO(2)/MCM-41 and 15 wt.% TPA on different zirconia loadings (10-70 wt.%)/MCM-41 were prepared and calcined at 1123 K. Catalysts were characterised by known techniques. Mesoporous silica supports play an important role in stabilising catalytically active TPA along with tetragonal phase of zirconia. Among the catalysts, 15 wt.% TPA/22.4 wt.% ZrO(2)/MCM-41 calcined at 1123 K was found to have the highest acidity and be at least four times more active than neat 15 wt.% TPA/ZrO(2) in veratrole acetylation to acetoveratrone by acetic anhydride.</p>1 aHalligudi, Shivaraj, B.1 aXu, R.1 aGao, Z.1 aChen, J.1 aYan, W.  uhttps://library.ncl.res.in/content/tungstophosphoric-acid-and-zirconia-supported-mesoporous-silica-catalyst-veratrole-0