【作者】 杨刚；

【导师】 韩秀文； 包信和；

【作者基本信息】 中国科学院研究生院（大连化学物理研究所） ， 有机化学， 2005， 博士

【摘要】 ZSM-5分子筛和TS-1分子筛都属于MFI型结构。它们之间的区别仅在于骨架硅是被铝还是被钛取代,但它们的催化与反应性能迥然不同。ZSM-5分子筛是一种良好的择型催化剂,广泛应用于石油炼制和化学工业,而TS-1分子筛是一种优良的选择氧化催化剂。本论文采用密度泛函理论结合核磁共振实验的方法,对这两种分子筛的结构、性质、吸附以及催化性能进行系统而深入研究,得到的主要结论有:1.运用核磁共振和理论计算方法,研究了La、P增强ZSM-5分子筛水热稳定性的机制,提出Al、O之间的静电势可作为衡量分子筛水热稳定性的参数;2.分别计算了H2O与ZSM-5分子筛（0 0 1）、（1 0 0）、（2 1 0）和（4 1 0）表面发生的氢交换反应。在不同的分子筛表面上反应性能会有所差异,且随反应分子体积的增大对表面结构敏感度也相应增加;3.利用核磁共振实验和理论计算研究了P（CH₃）₃分子在TS-1分子筛上的吸附行为。我们设计出一种新缺陷位,它可以提供Bronsted质子酸。同时证实了Silicalite-1中不能形成Bronsted酸中心;4.苯乙烯在TS-1分子筛上的氧化反应存在两条竞争途径:自由基和环氧化。在归属核磁共振峰的基础上,我们提出自由基反应机理。5.苯乙醛是由半缩醛而不是环氧苯乙烷转化生成的。极性溶剂的存在促使Bronsted酸中心的形成,大大降低了半缩醛转化生成苯乙醛的活化能,有力的解释了苯乙烯在TS-1分子筛上与H₂O₂反应生成苯乙醛的实验结果。更多还原

【Abstract】 Both zeolite ZSM-5 and zeolite TS-1 belong to MFI type, and the only difference between them is the substitution of framework Si by Al or by Ti. However, the catalytic and reactive properties of these two zeolites can be almost totally different. Zeolite ZSM-5 is a good shape selective catalyst in petroleum refining and chemical industry, whereas zeolite TS-1 is used as an excellent selective oxidation catalyst. Combining NMR experiments with theoretical calculations, the present work was carried out to study the properties, adsorptions and reactivities related to these two zeolites, with the main findings summarized below:1. By 27Al MAS NMR, 27Al 3Q MAS NMR experiments and density functional calculations, the mechanism is proposed why La and P can contribute to the enhancement on the hydrothermal stability of ZSM-5 zeolite. Moreover, the electrostatic potential is found as one effective parameter to measure the hydrothermal stability.2. Four representative surfaces were selected to explore the differences of different ZSM-5 zeolite surfaces. The larger the reactant molecule, the more dependent to the zeolite surface. Such a rule is believed applicable to other zeolites besides ZSM-5.3. There are four framework Ti species existing in TS-1 zeolite, including the new defect site designed by us. This defect site can provide Bronsted acidic proton to the adsorbed molecule, which is consistent with our NMR experiments. Meanwhile, silicalite-1 was confirmed to have no Bronsted acidic protons.4. There are two competing reaction pathways for styrene oxidation over TS-1 zeolite: radical and epoxidation. Combing with theoretical calculations, the peaks更多还原