02262nas a2200241 4500008004100000022001400041245010100055210006900156260007300225300001200298490000700310520141400317653001501731653001301746653001601759653001101775100001301786700001901799700002101818700002101839700002801860856013201888 2005 eng d a1387-181100aBenzylation of benzene and other aromatics by benzyl chloride over mesoporous AlSBA-15 catalysts0 aBenzylation of benzene and other aromatics by benzyl chloride ov aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a195-2030 v803 a

Aluminum-containing mesoporous molecular sieves AISBA-15 with different n(Si)/n(Al), ratios and AIMCM-41 have been synthesized hydrothermally and characterized in detail by physicochemical methods, viz. XRD, N(2) adsorption and (27)Al NMR spectroscopy. The low angle XRD and N2 adsorption measurements reveal that the structural order of SBA-15 was retained after the incorporation of Al. The increase of the unit cell parameter with increasing aluminum content and (27)Al MAS NMR spectroscopy confirm the incorporation of aluminum in the framework. Benzylation of benzene and substituted benzenes reaction employing benzyl chloride as the alkylating agent over AISBA-15 and AIMCM-41 have been investigated. The influence of various reaction parameters such as reaction temperature, reactant feed ratio and catalyst amount affecting the activity and selectivity of AISBA-15, have been studied. Among the mesoporous catalysts studied, AISBA-15(45), where the number in parentheses indicates the molar nsilnA, ratio, shows both high conversion and high selectivity for the benzylation of benzene. The activity of this catalyst for the benzylation of different aromatic compounds is in the following order: benzene > toluene > p-xylene > mesitylene > anisole. Kinetics of the benzene benzylation over different catalysts have also been investigated. (c) 2005 Elsevier Inc. All rights reserved.

10aAlkylation10aAlSBA-1510aBenzylation10aSBA-151 aVinu, A.1 aSawant, D., P.1 aAriga, Katsuhiko1 aHartmann, Martin1 aHalligudi, Shivappa, B. uhttps://library.ncl.res.in/content/benzylation-benzene-and-other-aromatics-benzyl-chloride-over-mesoporous-alsba-15-catalysts-002033nas a2200253 4500008004100000022001400041245009700055210006900152260007300221300001200294490000800306520115300314653001201467653001301479653002701492653002501519653001101544100001301555700002201568700002801590700001701618700002101635856012301656 2005 eng d a0926-860X00aHighly active and selective AlSBA-15 catalysts for the vapor phase tert-butylation of phenol0 aHighly active and selective AlSBA15 catalysts for the vapor phas aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAR a207-2130 v2813 a

Hexagonally ordered mesoporous AISBA-15 catalysts having n(Si)/(nA]) ratios from 7 to 215 have been synthesized hydrothermally using a cheap non-ionic block copolymer as the structure-directing agent. The obtained materials were analyzed by XRD and nitrogen adsorption to determine the structural order and the textural properties. It has been observed by Al-27 MAS NMR spectroscopy that aluminum atoms are exclusively in tetrahedral coordination for all samples except AISBA-15(7), where octahedral aluminum has been detected to some extent. Temperature-programmed desorption of pyridine showed that AISBA-15(45) has a higher number of strong acid sites as compared to other mesoporous materials such as FeMCM-41, AIMCM-41 and FcAlMCM-41. The catalyst AlSBA-15(45)showed superior performance in the acid-catalyzed tertiary butylation of phenol employing tert-butanol as the alkylation agent. A high phenol conversion of 86.3% is observed for this catalyst at a reaction temperature of 150 degrees C. Over AISBA-15(45), the 4-TBP yield amounts to 40.5% and the 2,4-DTBP yield corresponds to 37.9%. (c) 2004 Elsevier B.V. All rights reserved.

10aAcidity10aAlSBA-1510aaluminum incorporation10abutylation of phenol10aSBA-151 aVinu, A.1 aDevassy, Biju, M.1 aHalligudi, Shivaraj, B.1 aBohlmann, W.1 aHartmann, Martin uhttps://library.ncl.res.in/content/highly-active-and-selective-alsba-15-catalysts-vapor-phase-tert-butylation-phenol-001722nas a2200229 4500008004100000022001400041245014100055210006900196260007300265300001200338490000800350520085900358653001601217653001101233653001301244653001401257653002101271100002601292700002101318700002801339856012501367 2007 eng d a1387-181100aEffect of pretreatment conditions on the catalytic activity of nano-sized TPA/ZrO2 dispersed in SBA-15 channels in acetylation reactions0 aEffect of pretreatment conditions on the catalytic activity of n aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY a223-2330 v1023 a

Acetylation of an aromatic compounds such as veratrole (1,2-dimethoxybenzene), anisole, thioanisole, isobutyl benzene and 2-methoxynaphthalene with acetic anhydride has been investigated over a nano-sized 12-tungstophosphoric acid (TPA)/22.4 wt.%ZrO2/SBA- 15 catalysts in the liquid phase conditions. Catalysts with different (%) TPA and zirconia loadings calcined at different temperatures were prepared by wet-impregnation and characterized by XRD, N-2 adsorption-desorption, FT-Rarnan, X-ray photoelectron spectroscopy (XPS). The acidic behavior of the catalyst was studied by TPD of ammonia and FT-IR pyridine adsorption. Among the catalysts, 15 wt.%TPA/22.4 wt.%ZrO2/SBA- 15 calcined at 1123 K had the highest acidity and was the most active catalyst in veratrole acetylation with acetic anhydride. (C) 2007 Elsevier Inc. All rights reserved.

10aacetylation10aSBA-1510aTPA/ZrO210averatrole10awet-impregnation1 aSawant, Dhanashri, P.1 aHartmann, Martin1 aHalligudi, Shivaraj, B. uhttps://library.ncl.res.in/content/effect-pretreatment-conditions-catalytic-activity-nano-sized-tpazro2-dispersed-sba-15