论文总字数：28896字

摘 要

金属有机多面体材料（MOPs）是由无机金属和有机配体在一定的条件下通过配位作用形成的一种具有离散结构的分子。MOPs具有密闭的空腔结构和丰富的物理化学性质，在吸附和催化等方面有着广泛的应用前景。然而，MOPs存在两方面的缺陷。首先，MOPs的稳定性差；其次，活化后MOPs易发生聚集，导致活性位堵塞从而丧失吸附和催化活性。针对上述问题，本文拟在介孔分子筛的限阈空间内构筑MOPs，同时提高MOPs的稳定性和分散性，改善MOPs的性能。

本文选用具有瓶颈结构的介孔分子筛SBA-16作为载体。其结构由孔穴和孔道组成，每个孔穴和八个孔道相连，孔穴的直径约为9 nm，而连接孔穴的孔道直径约为2 nm。我们使用双溶剂的方法将MOPs引入到SBA-16的孔道中，由于MOPs的分子尺寸（约为3 nm）小于SBA-16的孔穴直径，大于SBA-16的孔道直径，因此，MOPs和SBA-16的复合材料中MOPs只能限制在SBA-16的孔穴中而不能游离到其孔道内。

本文使用双溶剂的方法合成MOP-SO₃H和SBA-16复合材料。通过考察复合材料和MOP-SO₃H对二氧化碳和丙烯的吸附容量，表明复合材料中MOP-SO₃H在SBA-16中呈现高度分散状态。对复合材料进行了性能探究，在催化氧化苯乙烯开环反应中，复合材料的转化率（99.0%）明显高于MOP-SO₃H的催化转化率（47.7%），这归因于复合材料中MOPs分散性好，催化活性位暴露完全。同时，我们发现复合材料的稳定性明显优于MOP-SO₃H，更重要的是，复合材料经过4次循环实验后，仍然能保持最初的催化活性。

关键词：金属有机多面体 双溶剂法 SBA-16 催化开环反应

ABSTRACT

Metal-organic polyhedral (MOPs), constructed through the coordination of metal ions and organic linkers, are molecules with discrete structures. MOPs have been firmly established as ideal candidates for potential use in pertinent applications such as catalysis and adsorption, due to their intriguing cavity structures, rich chemical and physical properties and the mild synthetic conditions. However, several drawbacks of MOPs can not be ignored when applying them in practical use. Firstly, MOPs molecules are unstable. MOPs can be present stably in the mother liquor but their structure tends to collapse when MOPs are exposed to air for some time, limiting the application of MOPs. Secondly, MOP molecules are easy to aggregate after activation, which results in the reduction of catalytic performance because most of the active sites will be blocked and inaccessible. This weakens the performance of MOPs materials do not exhibit any visible adsorption or catalytic activity at all. In order to solve the above problems, we developed a strategy to adjust the properties of MOPs by incorporating SBA-16, improved the stability and dispersibility of MOPs.

A typical cage-like ordered mesoporous silica, SBA-16, has tunable cage size (9 nm) and its cages are interconnected three-dimensionally by eight tunable pore entrance (about 2 nm). MOPs were introduced into the cages of SBA-16 by using double solvents method. Under the effect of a non-polar solvent n-hexane, copper nitrate and organic ligands which dissolved into a polar solvent methanol, enter into the cage of SBA-16 completely to generate MOPs. The large cages of SBA-16 can accommodate MOP molecules of large molecular size (about 3 nm), whereas the smaller pore entrance may prevent leaching of the MOP molecules confined in the mesoporous cage. As a result, the MOP molecules can be incorporated into the cage of SBA-16 to fabricate a new type of composite.

Composite MOP-SO₃H/SBA-16 was synthesized by double solvents method. A series of composites characterization proved that MOP-SO₃H successfully introduced into the cavities of SBA-16. At the same time by examining the carbon dioxide and propylene adsorption capacity of composite and MOP-SO₃H, we concluded that MOP-SO₃H presented in a highly dispersed state in the cavities of SBA-16. We also conducted the ring-opening reaction catalyzed by MOP-SO₃H and the composites. The results shows that the reaction catalyzed by the composite MOP-SO₃H/SBA-16 can reach a conversion rate of 99.0% after reaction for only 30 min at 0 °C, which is obviously higher than that of MOP-SO₃H (47.7%). This is owing to the dispersing of MOP-SO₃H. Moreover, the catalytic activity can be well recovered without any loss even after four cycles.

Key Words：Metal-organic polyhedra；Double solvents method；SBA-16；Catalyzed ring-opening reaction

目 录

摘 要 I

ABSTRACT II

目 录 i

第一章 绪论 1

1.1 金属有机材料 1

1.2 Paddle-Wheel次级结构单元 2

1.3 金属有机多面体的应用 4

1.3.1 对生物分子的识别 4

1.3.2 催化性能 5

1.3.3 吸附性能 6

1.4 介孔氧化硅SBA-16 9

1.5 本论文的研究意义和内容 9

第二章 实验设备和分析方法 11

2.1 实验原料 11

2.2 样品制备 12

2.2.1 金属有机多面体MOP-SO₃H的制备 12

2.2.2 介孔氧化硅SBA-15和SBA-16 12

2.2.3 金属有机多面体/介孔氧化硅复合材料 12

2.3 样品表征 14

2.3.1 X射线粉末衍射 14

2.3.2 傅里叶变换红外光谱 14

2.3.3 比表面积和孔结构 14

2.3.4 热重 14

2.3.5 紫外可见漫反射光谱 14

2.4 催化和吸附性能测试 15

2.4.1 催化性能测试 15

2.4.2 吸附性能测试 15

第三章 结果与讨论 16

3.1 复合材料合成过程分析 16

3.2 复合材料的表征 17

3.2.1 X射线粉末衍射 17

3.2.2 傅里叶变换红外光谱 18

3.2.3 比表面积和孔结构 19

3.2.4 紫外可见漫反射光谱 20

3.2.5 热重 21

3.3 稳定性测试 21

3.4 复合材料分散度测试 22

3.5 复合材料的催化性能测试 24

第四章 结论与展望 27

4.1 结论 27

4.2 展望 27

参考文献 28

致 谢 32

第一章 绪论

1.1 金属有机材料

金属有机材料也称为有机无机杂化材料，是由无机金属部分与有机配体在一定的条件下通过自组装的方式形成的一种结构丰富多样、高度归整并且具有一定周期性的晶态材料^[1]。根据金属有机材料结构的不同可以将其分为两类：一类是具有分立结构的晶态材料，主要包括纳米球、多边形分子以及金属有机多面体材料（Metal-Organic Polyhedra, MOPs）等一些零维的寡聚物；另一类是具有聚合结构的晶态材料，主要包括一维的配位聚合物、二维的层状聚合物以及三维的金属有机骨架聚合物（Metal-Organic Frameworks, MOFs）等（图1-1）^[2]。

金属有机骨架材料（MOFs）是近十年来发展迅速的一种配位聚合物，具有三维的孔结构，一般以金属离子为连接点，有机配体位支撑构成空间3D延伸，系沸石和碳纳米管之外的又一类重要的新型多孔材料，在催化，储能和分离中都有广泛应用，目前，大多数研究人员致力于氢气储存的实验和理论研究。同时，由于具有纯度高、结晶度高、成本低、能够大批量生产、结构可控等优点，正受到全球范围的极大关注，近年来已成为国际储氢界的研究热点。

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