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xmclyn

铁杆木虫 (知名作家)

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专业: 高分子合成化学

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rabbit7708(金币+1,VIP+0):多谢热心应助！：）

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Originally posted by wang_jiyuan at 2007-11-29 08:41:
能不能把文献也发到我的邮箱啊，多谢了。
wang_jiyuan@163.com

Journal of Catalysis 204, 110–117 (2001)

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21楼2007-11-30 12:51:32

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雁过无痕

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Originally posted by chenwei19828888 at 2007-11-29 13:26:
钛硅介孔材料,对环氧化物的选择性很高

给个参考文献多谢

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2025年招收硕士2名（可调剂），博士1名。招收药物固态化学教学科研人员（博士后或特聘副教授）各一名。

22楼2007-11-30 15:32:20

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chenwei19828888

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buffaloli(金币+1,VIP+0):多谢应助了！
buffaloli(金币+0,VIP+0):帮你把abstract加上了。

钛硅介孔材料在双氧水,或有机过氧化物做为氧化剂的条件下,对环氧化物的选择性很高
  例如,J Porous Mater  2006  13  81-89

M. Ramakrishna Prasad1 , G. Madhavi1, A. Ramachander Rao1, S. J. Kulkarni1  and K. V. Raghavan1

(1)  Indian Institute of Chemical Technology, Hyderabad, 500 007, India

Received: 24 December 2003  Revised: 8 August 2005

Abstract  A series of titanium rich isomorphous substituted Ti MCM-41 and HMS materials have been synthesized with different Si/Ti ratios. The highest amount of Ti incorporated in synthesis gel is in TiMCM-41 (Si/Ti = 10). Whereas for TiHMS catalysts, Ti is incorporated up to Si/Ti = 50 successfully without forming any extra framework TiO2. Cyclohexene epoxidation reaction with dry tert-butyl hydroperoxide (TBHP) as an oxidant has been studied to evaluate the catalytic properties of Ti substituted mesoporous catalysts. The effect of molar ratio of substrate

xidant in this reaction has been studied and high conversion, high selectivity were achieved at 2: 1 molar ratio with TiMCM-41 (Si/Ti =25). Dry TBHP (in dichloromethane) and chloroform were found as good oxidant and solvent system for this reaction. Pure siliceous mesoporous silica and low `Ti' substituted mesoporous silicas were found to be efficient catalysts for oxidation of cyclohexene. An interesting variation of the selectivity from allylic oxidation to epoxidation during oxidation of cyclohexene was observed with an increase in the Ti amount in the mesoporous framework. The allylic oxidation of cyclohexene has been carried out using molecular oxygen as an oxidant and in the presence of a small amount of TBHP as initiator. Siliceous HMS materials gave better conversion compared to MCM-41 type of materials and other conventional silicas like silica gel, fumed silica etc. in allylic oxidation of cyclohexene. Epoxidation of higher cyclic olefins like cyclooctene, cyclododecene, cis-cyclododecene and linear olefins 1-Heptene, cis-2-hexene, 1-undecene was carried out over TiMCM-41 (Si/Ti = 25). Ti substituted mesoporous catalysts were characterized by elemental analysis, XRD, FTIR, UVDRS, 29SiMASNMR, BET surface area and pore size distribution techniques.
Keywords TiMCM-41 - TiHMS - Epoxidation - Allylic oxidation - TBHP and molecular oxygen

[ Last edited by buffaloli on 2007-12-3 at 12:56 ]

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23楼2007-11-30 15:39:30

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