【作者】 王晓东；

【导师】 张宝泉；

【作者基本信息】 天津大学 ， 工业催化， 2008， 博士

【摘要】 钛硅分子筛(TS-1)膜具有沸石膜材料的独特性能,可用于膜反应器,实现反应与分离过程的有效集成,以提高反应转化率,达到强化反应过程的目的;除此之外,TS-1膜可制成透明材料,在光学器件上有潜在应用;还可作为纳米材料的基体进行原子簇和超分子化合物的组装,以获得新的光学、电化学、光电子材料,应用于光电子、电化学领域。该膜具有优异的催化氧化性能,对于有H2O2参与的有机物择形氧化反应性能良好,反应后H2O2转化成H2O,对环境无污染。基于此,TS-1膜的合成与应用,引起世界范围的广泛关注。本论文的研究内容包括以壳聚糖为引导剂,在多孔Al2O3载体上b轴取向TS-1膜的制备及其形成机理;以无机物TiCl3为钛源,及使用微波辐射加热法,在多孔Al2O3载体上TS-1分子筛膜的合成;TS-1膜在正己烷部分氧化反应中的应用。利用载体表面性质对成膜的影响,分别在α-氧化铝,壳聚糖修饰的α-氧化铝、氧化锆修饰的α-氧化铝以及多孔不锈钢等载体上合成了TS-1膜。研究了不同的合成液组成及反应条件对膜结构的影响,包括模板剂TPAOH浓度及反应温度的影响。以壳聚糖修饰的α-氧化铝为载体,TPAOH浓度较低,180°C晶化温度下可得到连续的b轴取向TS-1膜。原子力显微镜、接触角测量、酸碱滴定、电子探针显微分析及X射线能谱分析证明TPAOH与TS-1前驱体同时吸附在壳聚糖膜的表面,形成凝胶层。结合不同结晶时间的扫描电镜照片推导出在以壳聚糖修饰的α-氧化铝载体上b轴取向TS-1膜的形成机理。即,在壳聚糖膜的表面形成TPAOH与TS-1前驱体的凝胶层,在凝胶层的底部结晶,晶核长成小晶体,晶体以b轴取向,晶体长得更大了,第一层晶体更紧密了,第五阶段,新的晶核在第一层晶体上形成,然后在第一层晶体的诱导下生长出第二层。采用无机物(TiCl3)为钛源制得TS-1分子筛膜。对所得膜材料进行扫描电镜、X射线衍射、红外及紫外-可见光谱、X射线能谱等检测。结果表明,用无机物(TiCl3)做钛源所得膜材料不含锐钛矿等杂质,钛含量低于胶液中钛含量,流失的钛存在于溶液中,不形成锐钛矿沉淀。采用微波法、二次生长-微波法及原位老化-微波法制备TS-1分子筛膜,对所得膜材料进行扫描电镜、X射线衍射、红外及紫外-可见光谱、X射线能谱等一系列表征。直接微波法得不到TS-1膜;二次生长-微波法得到的膜不够连续,并且有二次成核现象,晶体大小不均一;原位老化-微波法制得连续膜,并且晶粒细小,均一。将所得的TS-1膜用于正己烷的部分氧化反应。以TiCl3为钛源与以原位老化-微波加热法制得的TS-1膜为催化剂时,钛含量低时,催化性能不理想。b轴取向的TS-1膜为催化剂时,催化活性与选择性均令人满意。更多还原

【Abstract】 Titanium silicalite-1 (TS-1) film possesses unique performance of zeolite films, By using zeolite film in the membrane reactors, the reaction and separation processes are efficiently integrated, the reaction rate is improved and the reaction is greatly intensified. It can also be used in the optical devices if made to be transparent material. On the other hand, atom cluster compounds and supramolecular compounds are assembled using the zeolite film as matrix, which are promising candidates in the fields of photoelectron and galvano-chemistry as new optical, electrochemical, and photoelectronic materials. It plays a positive role in the regioselective oxidation reaction of organic compounds, with H2O2 as oxidant. The reaction is environmentally friendly as H2O2 is transformed into H2O. therefore, the synthesis and applications of TS-1 films have attracted worldwide attention.In this dissertation, the b-oriented TS-1 film was synthesized on the porous Al2O3 substrate by the induction of a chitosan layer, and the formation mechanism was further studied. The continuous TS-1 film was also fabricated by using the inorganic compound TiCl3 as titanium source, and by using the microwave method. Utilizing the surface property of substrates, TS-1 films were synthesized on theα-Al2O3, chitosan-modifiedα-Al2O3, ZrO2-modifiedα-Al2O3 and porous stainless steel substrates. The influence of the concentration of TPAOH and the synthesis temperature on the structure of the synthesized film was studied When the chitosan-modifiedα-Al2O3 was used as the substrate, the continuous b-oriented TS-1 film was obtained under lower TPAOH concentration and the crystallization temperature of 180°C.A layer of gel was formed on the surface of the chitosan film by adsorbing TPA and TS-1 precursors simultaneously, which was proved by AFM and contact angle measurements, acid-base titration, EPMA analysis and EDX analysis. In light of this result and the SEM images of the TS-1 films, we proposed a new film formation mechanism. That is, firstly, a gel layer of TPA and TS-1 precursors is formed on the surface of chitosan film. Then, nucleation occurs in the interior absorbent layer near the chitosan film, the nuclei grow to be small crystals, and the small crystals are b-oriented. In the fourth stage, the crystals grow larger, and the first layer becomes continuous. In the fifth stage, new nucleation occurs on the crystals in the first layer, and then, by the induction of the crystals in the first layer, the second layer is formedThe TS-1 film was fabricated with inorganic compound TiCl3 as titanium source. The film was investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), FI-IR and UV-Vis spectra, and EDX, which demonstrated that the anatase was avoided, the content of titanium element in the TS-1 film was lower than that in the synthesis solution, the lost titanium element existed in the solution, and no anatase was formed.By using the microwave heating method, the second growth-microwave heating method and the in situ aging-microwave heating method, the TS-1 zeolite films were fabricated. The films were characterized by SEM, XRD, FI-IR and UV-Vis spectra, and EDX. The results indicated that the TS-1 film can not be obtained by the microwave heating method, the film was not continuous by the second growth-microwave heating method, new nuclei appeared, in the process of nucleation, and the crystals in the film were not uniform. By using the in situ aging-microwave heating method, the film was continuous with small and uniform crystals.The synthesized TS-1 films were applied in the oxyfunctionalization of n-hexane. TS-1 film synthesied with TiCl3 as titanium or by using the in situ aging-microwave heating method displays weak catalytic performance due to the low titanium content in the film. When the b-oriented TS-1 film was used, the reactivity and selectivity were both satisfactory.更多还原