【作者】 刘森；

【导师】 肖丰收；

【作者基本信息】 吉林大学 ， 无机化学， 2010， 博士

【摘要】 本论文致力于合成新型多孔氧化硅材料及其性能研究。作者采用新的合成技术,制备出具有新颖结构的多孔氧化硅材料,并通过一系列表征手段对所合成的材料进行表征,仔细研究材料的结构。同时,我们对合成的材料进行了催化反应、大分子蛋白酶的吸附等方面的性能研究。第一章为绪论部分,作者主要介绍了多孔材料的基本概念、性质以及多孔材料的应用。其中,作者详细的介绍了介孔材料的概念、合成方法、合成机理、结构性质以及应用等方面的基础知识。第二章中,作者采用以尿素作为pH自调节剂的方法,一步合成了杂原子参杂的介孔材料(Fe-SBA-15、Al-SBA-15)。作者采用多种表征手段,详细的研究了它们的结构性质。此外,并且测试了Fe-SBA-15在苯的苄基化反应中的催化性能。第三章中,作者以尿素高温分解产生的气体作为模板,合成了具有额外较大介孔的有序介孔材料。该材料既保持了有序的介孔结构,同时又含有大量的额外介孔,并且在肌红蛋白酶的吸附实验中,显示了很好的吸附效果。第四章中,作者采用离子液体作为模板剂,在强酸性体系中,合成出三维立方介孔材料,其孔径在超微孔的范围内。此外,作者采用离子液体为模板剂,在不同的碱体系中,合成出多种介孔氧化硅材料,并对其结构进行了表征。第五章中,作者采用在合成Beta分子筛的过程中,直接加入高温稳定的氟碳表面活性剂的方法,一锅法合成由纳米粒子组装的大块沸石。该材料不仅保持了纳米分子筛的特点,同时还具有很好的催化性能。更多还原

【Abstract】 Since the discovery of natural zeolites, inorganic porous materials have been paid much attention by researchers all over the world. Normally, compared with conventional non-porous materials, porous materials have some unique properties such as large BET surface area, abundant porous structure, and uniform pore size distribution. Therefore, inorganic porous materials have been widely applied in many fields due to their special properties. Notably, among numerous inorganic porous materials, microporous zeolites and mesoporous materials have been widely studied. Since the first natural zeolite was discovered in 1976, zeolites have been widely exploited instead of conventional materials. Furthermore, scientists began to prepare zeolites by applying the synthesis conditions similar to that of natural zeolites in 1940s, and they achieved a lot of good results. With the in-depth study of zeolites, there are some novel synthesis routes invented to prepare various zeolites. Up to now, the number of zeolites on structure basis is more than one hundred, and the compositions of zeolites are changed from original silica and aluminum to different other elements, even other non-silica microporous materials have been prepared. Thus, zeolites have been widely applied in catalysis, adsorption and separation, ion-exchange and so on. However, due to their relative smaller pore size, they are limited for application in bulky molecules. In 1992, the Mobil scientists reported the M41S materials, which offer a new guide for porous materials. Generally, mesoporous materials not only have large BET surface area, abundant porous structure, and uniform pores size distribution which are similar to zeolites, but also exhibit large pore size which can be changed from 2 nm to more than 30 nm. Additionally, they can be easily modified in order to introduce more activity sites. Since the discovery of M41S, mesoporous materials have been widely studied in catalysis, adsorption and separation, ion-exchange, drug release and so on. Although, there are many kinds of mesoporous materials and zeolites, the hot issues are in the centre of porous silica-base materials, which are important to exploit and apply porous materials.Here, we study the synthesis process of porous silica-based materials. In addition, we prepare the porous materials with unique properties in order to meet the requirements under various conditions by using novel synthesis routes.In recent years, metal heteroatom containing SBA-15s have been widely studied. However, their synthesis methods are relatively complex, which limited their further applications. Therefore, it is necessary to prepare these SBA-15s by a simple and effective route. In order to simplify the synthesis process, we have added urea during the process. The pH value of the mixture can be changed to neutral by ammonia, which comes from the decomposition of urea in the mixture. Furthermore, we can adjust the synthesis temperature to control the decomposition rate of urea, which can make the pH change slowly. By using this new route, we prepare heteroatom containing SBA-15 (Fe-SBA-15, Al-SBA-15). The multiple characterizations exhibit the samples have good mesostructure. Additionally, Fe-SBA-15s show good catalytic property in Friedel-Crafts benzylation of benzene.Particularly, SBA-15 plays an important role in application of bulky molecules because of its relative large pore size compared with MCM-41. However, the diffusion of large biomolecules and proteins in SBA-15 is limited due to its pore size and 2D channels. Thus, it is necessary to increase the diffusion rate of bulky molecules in SBA-15. In this article, we introduce urea during the synthesis process of SBA-15, and abundant gaseous decomposed from urea in the mixture. By carefully controlling the synthesis condition, the gaseous can be used as a good template to produce large mesopores. Notably, the samples have both the good mesoporous structure and additional large mesopores. Furthermore, we have done the adsorption of myoglobin on the samples, and the results show they exhibit good adsorption capacity. Generally, phases with a three-dimensional pore system are believed to be more advantageous for catalytic applications than phases having a one-dimensional array of pores. However, due to the limitation of synthesis condition, the pore size of three-dimensional pore system is more than 2 nm. In this part, we prepare a lot of mesoporous materials templated by ionic liquids in the presence of chlorhydric acid, sodium hydroxide, ammonia water, or tetramethyl ammonium hydroxide. Among these materials, the three-dimensional pore system material (space group Pm3n) can be prepared in the presence of chlorhydric acid, and its pore size is smaller than 2 nm. The samples have potential applications for shape-selective reaction and selective adsorption.Finally, compared with conventional zeolites, nano-zeolites have some unique properties such as large extra surface area which can make the guest moleculars easily contact with catalytic active sites. At the same time, nano-zeolites can increase the diffusion rate of catalytic molecular. However, they are limited for further application by the complex separation process and relative lower crystallinity. In this part, we prepare the bulky zeolites materials which are self-assemble by nano-Beta using direct introduction of the fluorocarbon surfactant during the synthesis process. The bulky materials not only contain high diffusion rate of guest moleculars in nano-zeolites, but also have good crystallinity. Notably, the bulky materials exhibit much higher catalytic activity then conventional Beta in the catalytic reactions such as cracking of isopropylbenzene and alkylation of phenol with tert-butyl alcohol.更多还原