作　　者： ; ; ; ; ; ; ;

机构地区： 广东工业大学轻工化工学院

出　　处： 《无机材料学报》 2005年第2期386-392,共7页

摘　　要： 以沉淀二氧化硅为硅源,钛酸四丁酯为钛源,四丁基氢氧化铵为模板剂,采用水热晶 化法合成了TS-2分子筛.在优化合成步骤的基础上,采用XRD、FT-IR、UV-Vis、SEM 等测试方法系统研究了晶化温度、凝胶Si／Ti对晶化动力学行为及TS-2分子筛晶相结构的影 响.结果表明:高纯TS-2分子筛的最佳晶化温度为175℃,过高的晶化温度易导致MEL结构 向MFI晶相结构的转变及晶粒的逐渐长大.高纯TS-2样品的极限Ti／Si值为0.04,高于此值 则生成非骨架钛氧化物,并造成相对结晶度和催化氧化性能显著降低. Titanium silicalite molecular sieve TS-2 was synthesized by hydrothermal crystallization using precipitate silica as Si source, tetrabutylorthotitanate(TBOT) as Ti source, tetrabutyl ammonium hydroxide (TBAOH) as template. The influences of crystallization temperature and Si/Ti of the pre-gel on the crystallization kinetics and the crystal structure of TS-2 were investigated systematically by using XRD, FT-IR, SEM, UV-Vis on the base of the optimized synthetic procedure. It could be concluded from the experimental results that the optimal crystallization temperature should be 175 degrees C. The higher crystallization temperature readily results in the increase of crystal particle size and the conversion of crystal structure from MEL to MFI. The highest value of Ti/Si(mol/mol) of TS-2 product should be 0.04. The higher value of Ti/Si(> 0.04) of TS-2 could result in the formation of extra-framework titanium, as well as the decrease of relative crystallinity and catalytic performance.

关 键 词： 钛硅分子筛 合成 沉淀二氧化硅

领　　域： [理学] [理学]