【作者】 郭建维；

【导师】 王乐夫； 崔英德；

【作者基本信息】 华南理工大学 ， 工业催化， 2001， 博士

【摘要】 钛硅分子筛是由钛氧四面体和硅氧四面体构成的一类杂原子分子筛，它是将钛引入全硅分子筛骨架的一种新型催化材料。这种分子筛具有很高的热稳定性、抗酸性、疏水性、良好的催化活性和选择性，尤其是在温和条件下（常压低温）对以工业级双氧水为氧化剂的多种有机物的氧化反应（如烷烃的氧化、烯烃环氧化、醇氧化、苯及苯酚的羟基化、酮类氨氧化等）具有独特的择形催化功能，且不会深度氧化和污染环境，被誉为绿色化学技术领域的新型催化剂，受到国内外学术界高度重视。钛硅分子筛的独特性能为研究高选择性的烃类氧化反应和开发环境友好新工艺奠定了基础，它的发明被认为是近十多年来沸石催化领域的里程牌。本文采用XRD、FT-IR、SEM、TG、EDS、UV-Vis等技术手段，研究了不同合成方法及条件对微孔钛硅分子筛TS-1、TS-2及中孔钛硅分子筛Ti-MCM-41、Ti-HMS、Ti-MSU、Ti-AA的结构与催化性能的影响，并以烯烃氧化反应为例考察了不同改性方法对钛硅分子筛催化氧化性能的影响。 分别以硅酸四乙酯（TEOS）和无定形氧化硅为硅源合成了具有MFI拓扑结构的TS-1分子筛。考察了影响TS-1晶粒度及晶化动力学行为的主要因素、改性方法对TS-1催化性能的影响以及TS-1的再生性能。TS-1分子筛催化剂晶粒大小影响其表面利用率，这是TS-1晶粒度对其催化性能有显著影响的内在原因。不同硅源合成TS-1的晶化动力学不同，无定形氧化硅合成TS-1的成核活化能En和生长活化能Ec分别为47.4KJ／mol和76.6KJ／mol，大于有机硅源TEOS（En、Ec分别为34.9KJ／mol和38.2KJ／mol）。金属Pd的负载导致TS-1分子筛催化活性降低，同时对氧化剂H₂O₂具有显著分解作用。对TS-1分子筛表面实施硅烷化处理，可以增强其表面疏水性，提高其催化氧化活性。失活后的TS-1分子筛可采用高温焙烧或溶剂洗涤法进行再生。 采用无定形氧化硅为硅源，通过使钛源TBOT与H₂O₂在低温下形成过氧化钛物种的方法合成了MEL型钛硅分子筛TS-2。这种方法具有操作简单、骨架钛含量高、可避免非骨架钛形成的优点。晶化温度对TS-2结晶动力学和晶粒大小有较大影响，超过185℃易导致MFI晶相混杂，并使晶粒增大。采用本方法合成的TS-2最大骨架钛含量为Ti／Si＜0.04，超过此范围易生成非骨架钛或六配位的钛更多还原

【Abstract】 Titanium silicalite molecular sieves are a type of heteroelements-containing molecular sieves which are comprised of Ti-0 tetrahedrons and S:-0 tetrahedrons. Being a new type of catalytic materials with incorporation of Ti atoms into the pure silicalite molecular sieves framework, titanium silicalite molecular sieves have the higher thermal stability, anti-acidity, hydrophobicity and the outstanding ability to catalyze various oxidation reactions selectively, such as alcohol oxidation, alkane oxidation, alkene epoxidation, ammoximation of cyclohexanone, oxidation or hydroxylation of aromatic compounds, et al. Because the deep oxidation and contamination to environment can be avoided by using titanium silicalite molecular sieves, it attract much attention all over the world and have been reputed as the green catalysts. The unique catalytic performance of titanium silicalite mdecular sieve has laid the foundation for research of high selectively cataly(?)e oxidation of hydrocarbons and development of new environmentally friendly oxidation technology. The invention of titanium silicalite molecular sieves has been considered as the milestone of the zeolite catalysis area during the last decade. The influences of different synthetic methods and conditions on the structures and features of TS-1,TS-2, Ti-MCM-41, Ti-HMS, Ti-MSU, Ti-AA have been investigated by characterization of XRD, FT-IR, UV-Vis, SEM, EDS, TG et al. in this paper. The influences of modifying methods on the catalytic performances of (?)anium silicalite molecular sieves have been valued through oxidation of alkenes.TS-1 with MFI topology has been synthesized using tetraethyl orthosilicate (TEOS) and amorphous silica as Si sources. The influencing factors of the particles size and crystallization kinetic, the influence of modifying method on the catalytic property and the regeneration of TS-1 have been investigated. The influence of the particle size of TS-1 on its catalytic activity has been attributed to (?)orrelation of the catalyst surface efficiency with the particle size of TS-1. The crystallization kinetics are different for synthesis of TS-1 using different Si sources. When amorphous silica更多还原