论文总字数：30304字

摘 要

醋酸与异丁烯加成酯化合成叔丁酯工艺是典型的原子经济反应过程，具有经济和环境的双重优势。为了提高醋酸叔丁酯的选择性，通常需要使用过量的醋酸或在反应体系中加入叔丁醇等极性溶剂，来促进异丁烯生成醋酸叔丁酯或抑制异丁烯发生聚合反应，这导致防腐蚀设备投资提高、后续产物分离能耗增大。因此，研制绿色高选择性的催化剂成为解决上述问题的重要途径。在我的导师汤吉海教授的课题组对丙磺酸改性介孔分子筛催化加成酯化反应研究已取得良好成果的基础上，以SBA-15为载体，采用一步水热法合成介孔材料M-PrSO₃H-SBA-15，通过金属掺杂引入新的酸位，来提高醋酸叔丁酯的选择性，并在此基础上探讨了不同酸位与催化活性的关系。

论文采用一步水热共缩合法制备了金属掺杂和丙磺酸嫁接的M-PrSO₃H-SBA-15。结构表征表明，M-PrSO₃H-SBA-15具有典型的六方相介孔结构和较好的规整度。金属的掺杂增加了弱酸的酸量，Fe和Ti的掺杂增加了中强酸的酸量，引入了Brönsted酸位，Al、Sn和Ce的掺杂引入了Lewis酸位。对比6组M-PrSO₃H-SBA-15在不同温度下催化醋酸与异丁烯加成酯化反应的催化性能发现，Brönsted酸量决定了加成酯化反应的反应速率，Brönsted酸与Lewis酸的酸量比例决定了醋酸叔丁酯的选择性。Brönsted酸吸附异丁烯，形成σ-络合物叔碳正离子，进而与醋酸和异丁烯反应生成醋酸叔丁酯和二异丁烯。Lewis酸位与异丁烯的相互作用，形成π-络合物，降低了微环境中与活性位Brönsted酸位接触的异丁烯的局部浓度，从而降低了异丁烯聚合的反应速率。利用金属掺杂和磺酸嫁接改性材料上形成的Lewis酸位和Brönsted酸位在酸烯酯化反应中存在的协同效应，提高了醋酸与异丁烯的反应中的醋酸叔丁酯的选择性。

关键词：M-SO₃H-SBA-15 酸位协同 加成酯化 醋酸叔丁酯

ABSTRACT

The direct addition of isobutene and acetic acid is a typical atomic economy reaction process to produce tert-butyl acetate with inexistence of the organic waste water, the process is has dual economic and environmentally friendly advantages. In order to improve the selectivity of tert-butyl acetate, an excess of acetic acid or polymerization inhibitor such as tert-butyl alcohol was added to the reaction system, which leads to promote the generation of tert-butyl acetate or suppress the occurrence of the polymerization of isobutene, resulting in a high cost of the corrosion-resistant equipment investment and subsequent product separation. Developing green catalysts to improve the selectivity of the target reaction is an efficient way to solve the above technical problems. Considering that, mental ions doped and sulfonic acid-modified materials were proposed in the present work. New acid sites could be incorperated into the nanospace of SBA-15 by metal ions doping, the relationship between the different acid sites and the catalytic activity was discussed and a could be plausible explanation was proposed for additive reaction of isobutene with acetic acid.

M-PrSO₃H-SBA-15 was prepared by co-condensation method with metal-doped and propylsulfonic grafted and the characterization data implied that the samples have typically mesoporous structure and different amount of Brönsted and Lewis acidity. Compared with the catalytic performance of M-PrSO₃H-SBA-15 at different temperatures one can find is that the rate of the additive reaction strongly depended on the Brönsted acidity, while the selectivity of tert-butyl acetate was linear correlated with the ratio of Brönsted and Lewis acid sites into the catalysts. It means that Brönsted acidity is the catalytic center of reaction. In addition, due to the strong interaction between the unsaturated bond in the olefin and Lewis acid sites, forming a π-complexation, causing lower local concentration of isobutene, thereby declining competitiveness of isobutene dimerization. In this way, the selectivity of tert-butyl acetate can be improved.

Our work showed that the catalytic performance of M-PrSO₃H-SBA-15 (M=Fe and Sn) is closely related to its surface acidity. In this section, a series of M-ArSO₃H-SBA-15 with adjustable acid intensity were synthesized by using CSPTMS as silane coupling agent. Comparing the structural and acidity of M-PrSO₃H-SBA-15, the results showed that Sn₅-Ar₁₀-Si and Fe₅-Ar₁₀-Si had similar parameters with Sn₅-Pr₁₀-Si and Fe₅-Pr₁₀-Si, except Ar₁₀-Si had ordering demaged in a certain degree and pore properties decreased.

KEYWORDS：M-SO₃H-SBA-15；Additive reaction；Acid intensity adjustment Tert-Butyl acetate；Synergic effect

目 录

摘 要 I

ABSTRACT II

第一章 文献综述 1

1.1 背景介绍 1

1.2 酸烯酯化催化剂 1

1.3 磺酸改性的介孔分子筛研究进展 3

1.3.1 磺酸改性介孔分子筛的合成与应用 3

1.3.2 多种官能团共同改性介孔材料的合成与应用 7

1.4 论文选题及研究思路 8

第二章 实验部分 10

2.1 实验原料及试剂 10

2.2 主要实验仪器及设备 10

2.3 催化剂的表征方法 11

2.3.1 小角度X射线衍射(SAXRD) 11

2.3.2 氮气吸附脱附(N₂-Adsorption Desorption) 11

2.3.3 氨气程序升温脱附(NH₃-TPD) 11

2.3.4 吡啶吸附红外光谱(Py-IR) 12

2.3.5 硫元素分析(Elemental Analysis) 12

2.3.6 酸碱滴定 12

2.4 催化性能评价及分析方法 13

2.4.1 实验方法 13

2.4.2 分析方法 13

第三章M-PrSO₃H-SBA-15中酸位在酸烯酯化中的协同作用 15

3.1 M-PrSO₃H-SBA-15的制备 15

3.2 M-PrSO₃H-SBA-15表征结果 16

3.2.1 小角度X射线衍射(SAXRD) 16

3.2.2 氮气吸附脱附(N₂-Adsorption-Desorption) 17

3.2.3 氨气程序升温脱附(NH₃-TPD) 18

3.2.4 吡啶红外(Py-IR) 20

3.3 M-PrSO₃H-SBA-15的催化性能 21

第四章 结论 25

参考文献 27

致谢 31

第一章 文献综述

1.1 背景介绍

醋酸叔丁酯能显著降低目标产物的大气光化学反应活性以及常温下的挥发性，从而有效避免部分有害物质进入大气中污染环境^[1]。例如，在有机溶剂工业中，用醋酸叔丁酯替代芳香烃和酮类，可以大大减少由有于毒溶剂排放造成的地面臭氧污染物的形成。因此，醋酸叔丁酯作为一种新兴的环境友好型溶剂，被广泛应用于涂料、表面活性剂等领域。

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