钛源浓度对合成Ti-MCM-41及其催化性能的影响  

Effects of Titanium Source Concentration on Synthesis and Catalytic Performance of Ti-MCM-41

作　　者：唐晓红[1] 吴崇珍[1] 李成未[1] 李保军[2] 郭益群[2] 

机构地区：[1]河南教育学院化学系,河南郑州450046 [2]郑州大学化学系,河南郑州450001

出　　处：《化工时刊》2011年第10期7-11,共5页Chemical Industry Times

摘　　要：在敞开体系中,以工业用水玻璃为硅源,以TiCl3为钛源,以三甲基十六烷基溴化铵(CTMAB)为模板剂,用H2SO4调节浆料的pH值,在浆料混和物物质的量比组成为n(SiO2)∶n(Na2O)∶n(CTMAB)∶n(TiCl3)∶n(H2O)7∶2.08∶1.4∶(0.070、.140、.28)∶530的范围内3,73 K搅拌晶化12 h,合成出了Ti-MCM-41,并用其催化氧化环己烯合成环氧环己烷。利用X射线衍射(XRD)、红外光谱(FT-IR)、紫外-可见光谱(UV-Vis)和孔结构测定对合成样品进行了表征。讨论了钛源浓度对分子筛晶化和催化氧化性能的影响。结果表明:在所考察的硅钛物质的量比范围内(100～25),利用敞开体系都能合成出良好长程有序性和结晶度的中孔分子筛Ti-MCM-41;将样品用于催化环己烯合成环氧环己烷,在硅钛物质的量比为100～25的范围内,随着钛源浓度的增加,进入分子筛骨架的Ti含量也随之增加,导致介孔硅骨架趋向混乱,使分子筛骨架对称性降低,样品的孔径、比表面积和比孔容减小,但并不影响样品催化氧化活性的增加。The mesoporous molecular sieve was synthesized by using silica from water glass of industry,titanium from TiCl3,H2SO4 for adjusting the pH of the slurry and CTMAB as template in an open-vessel.The mole ratio of the slurry mixture was： n（SiO2）∶n（Na2O）∶n（CTMAB）∶n（TiCl3）∶n（H2O）=7∶2.08∶1.4∶（0.07,0.14,0.28）∶530.The product was producted by making the mixed slurry crystallize at 373 K for 12 h and used as catalyst in catalytic oxidation of cyclohexene to epoxy cyclohexane.The characterization of its crystal order and framework titanium was carried out by means of X ray diffraction（XRD）,Fourier transform infrared spectrometer（FT-IR）,Visiblespectroscopy（UV-Vis） and mensuration of pore structure.The effects of titanium source concentration on the crystal parameter and catalytic oxidation activity of the mesoporous molecular sieve was discussed.The results showed that within the limits of discussed silicon titanium molar ratio（100~25）,mesoporous molecular series Ti-MCM-41 with good Long-range order and crystallinity can be prepared in an open system.The framework symmetry,specific surface area,pore volume and pore diameter of Ti-MCM-41 reduces gradually along with increasing titanium source concentration and Ti content into the molecular sieve framework which leads to mesoporous silica skeleton tending to chaos,but its increasing activity isn＇t affected in catalytic oxidation of cyclohexene to epoxy cyclohexane.

关 键 词：中孔分子筛 催化氧化 钛源浓度 

分 类 号：O643.36[理学—物理化学]