【摘要】 分别采用1,4-(双乙氧基硅烷)苯(1,4-BTEB)和1,2-三乙氧基硅基乙烷(1,2-BTESE)作为有机硅源,正硅酸乙酯(TEOS)为无机硅源,钛酸四丁酯(TBOT)为钛源,以Pluronic EO20PO70EO20(P123)为模板剂在酸性环境下水热合成制备了Ti掺杂的有机-无机有序介孔有机硅材料Ti-SBA-15-ben和Ti-SBA-15-et.同时,在合成过程中加入H2O2作为配合剂调节钛源水解速度,制备得到Ti-SBA-15-ben-H和Ti-SBA-15-et-H.采用FT-IR、DR UV-Vis、N2物理吸附、XRD、TG-DSC、TEM等方法对制备的样品进行了表征.结果表明:合成过程中加入H2O2制备的苯基桥连有机硅杂化材料具有较好的疏水性能,其骨架中活性4价位钛含量高,结构有序性最好.在以叔丁基过氧化氢(TBHP)为氧源的环己烯氧化反应中对制备的催化材料进行了对比评价,结果表明:Ti-SBA-15-ben-H表现出最高的催化活性,其催化的反应以环氧化产物为主,环己烯的转化率为26.9%,环氧选择性为32.8%,T i-SBA-15-et催化的反应以烯丙位氧化产物2-环己烯-1-酮为主,环己烯的转化率为8.5%,2-环己烯-1-酮选择性为41.2%.更多还原

【Abstract】 The Ti incorporated periodic mesoporous organosilicas with benzene or ethane bridging groups in the mesoporous wall were assembled by using mixed tetrabutyl titanate as the titanium sources and tetraethyl orthosilicate as the inorganic silica sources and 1,4-bis( triethoxysilyl) benzene or 1,2-bis( triethoxysilyl) ethane as the organic silicon source and triblock copolymer as the structure-directing agent in acidic media through the hydrothermal method. The benzene-bridged mesoporous organosilicas and the ethane-bridged mesoporous organosilicas were signed as Ti-SBA-15-ben and Ti-SBA-15-et,respectively. Meanwhile,the hydrogen peroxide was added to adjust the hydrolysis rate of tetrabutyl titanate and got the sample Ti-SBA-15-ben-H and Ti-SBA-15-et-H. Samples were characterized by N2 adsorption / desorption,FT-IR,ICP,TG-DSC,UV-Vis and TEM. Results showed that the benzene-bridged mesoporous organosilicas adding hydrogen peroxide during the synthesis process can maintain the best mesoporous structure and the highest activity of four levels of titanium in the mesoporous wall. The periodic mesoporous organosilicas were evaluated in the cyclohexene oxidation with TBHP( tert-butyl hydroperoxide) as oxidant agent. The reaction results were as follows: Ti-SBA-15-ben-H showed the highest catalytic activity and its c atalytic reaction is given priority to double bond oxidation products,the cyclohexene conversion and the epoxy c yclohexane selectivity were 26. 9% and 32. 8%,respectively. Oxidation of cyclohexene catalyzed by Ti-SBA-15-et gave priority to allyl oxidation products such as 2-cyclohexene-1-ketone,the cyclohexene conversion was 8. 5% and the 2-cyclohexene-1-ketone selectivity was 41. 2%.更多还原