【作者】 楚华琴；

【导师】 万颖；

【作者基本信息】 上海师范大学 ， 物理化学， 2009， 硕士

【摘要】 钛硅分子筛是一类重要的氧化催化剂,如具有MFI和MFL结构的TS-1、TS-2分子筛,在以双氧水为氧化剂时,能催化氧化多种有机化合物。但是它们应用于催化氧化大分子化合物时常常会受到其孔径(7?)的制约。MCM-41、MCM-48、SBA-15等新型介孔分子筛的发现,为合成具有大孔孔道的催化剂提供了新的方向。由于SBA-15的孔径可以在很大的范围调控,具有很高的水热稳定性,含钛的SBA-15具有更加重要的应用前景,因而受到人们的普遍关注。本文在钛-氧化硅、含钛有机功能化的钛硅介孔分子筛的合成及其在烯烃环氧化反应中的应用方面进行了研究,主要包括以下几个方面:第一章为文献综述,主要介绍了钛硅介孔分子筛合成及应用的主要现状。第二章介绍了以“酸碱对”混合钛源和无机硅源通过水热法合成钛硅介孔分子筛材料,并应用于1-辛烯环氧化反应体系。混合钛源为四氯化钛和钛酸正丁酯,硅源为正硅酸乙酯,有机结构导向剂为三嵌段共聚物P23。XRD,TEM,FT-IR,Uv-vis和氮吸附表明,经500°C高温去除表面活性剂的钛硅介孔分子筛材料具有高度有序的介孔结构,大比表面积(986– 1349 m2/g)和孔容(0.81– 1.2 cm3/g),均一的孔径(4.5– 6.3 nm),以及Ti-O-Si共价键。通过将材料应用与1-辛烯环氧化反应体系中,催化剂显示了较高的催化活性。第三章主要利用无机钛源和混合硅源通过水热法合成有机功能化钛硅介孔分子筛材料的合成,并应用于1-辛烯环氧化反应体系。XRD,TEM,FT-IR,Uv-vis和氮吸附表明,经500°C高温去除表面活性剂的钛硅介孔分子筛材料具有高度有序的介孔结构,大比表面积(421– 980 m2/g)和孔容(0.51– 1.3 cm3/g),均一的孔径(6.3–8.0 nm),以及Ti-O-Si共价键。将材料应用与1-辛烯环氧化反应体系中,通过催化性能比较发现提高材料的疏水性可以提高材料的催化活性。第四章研究了利用酚醛树脂,钛酸异丙酯和正硅酸乙酯为前驱体,利用溶剂挥发自主装技术合成比表面积大、有序度高,且硅钛摩尔比例可调的介孔聚合物-氧化钛硅分子筛纳米复合材料,并应用于1-辛烯环氧化反应体系。。通过氮气气氛下350℃去除表面活性剂的聚合物-氧化钛硅分子筛纳米复合材料具有高度有序的介孔结构,有机组分与无机组分混合均匀,大比表面积(476– 711m2/g)和孔容(0.49– 0.76 cm3/g),均一的孔径(6.6–8.2 nm),以及Ti-O-Si共价键。通过调节有机聚合物的含量来改变材料的亲疏水性。将材料应用与1-辛烯环氧化反应体系中,通过催化性能比较发现提高材料的疏水性可以提高材料的催化活性。第五章介绍了用后嫁接法,以不同的钛源为前驱物,以未去除表面活性剂的SBA-15为载体制备不同钛含量的钛硅介孔分子筛,并应用于1-辛烯环氧化反应体系。更多还原

【Abstract】 The discovery of Ti-containing molecular sieves added a new dimension to the applications of molecular sieves in catalysis. Titanium silicate, TS-1, and TS-2 with MFI and MEL structures, respectively, were shown to the active for selective oxidation of a variety of organic compounds in the presence of hydrogen peroxide. However, these applications were restricted to molecules smaller than 7 ? owing to the pore size limitation. This barrier was overcome with the introduction of mesoporous molecular sieves such as MCM-41, MCM-48 and SBA-15. Because of the wide pore size distribution and highly hydrothermal stability, titanium-containing SBA-15 seems more attractive in the application of catalytic oxidation of large organic molecules.In this thesis, we have prepared novel Ti-containing mesoporous silicates and studied their catalytic performance in oxidation of octene.The thesis is composed of five chapters. The fist chapter is a detaild review on the syntheses of Ti-containing molecular sieves and their catalytic performances.Chapter 2 introduces a novel method of syntheses of Ti-containing molecular sieves. Using mixed inorganin“acid-base pairs”(TiCl4 and tertrabutyl titanate) as the titanium sources and tetraethoxysilane as silica source and triblock copolymer as the struture-directing agent through hydrothermal methode.Characterization using XRD,Uv-vis, FT-IR,TEM and nitrogen sorption isotherm techniques reveals that the Ti-containing molecular sieves posses ordered 2-D hexagonal mesostructures,highly surface areas(986– 1349 m2/g),uniform pore sizes (4.5– 6.3 nm), large pore volumes(0.81– 1.2 cm3/g),and tetrahedrally incorporated titanium species in silica network. The Ti-containing molecular sieves show catalytic performance in the epoxidation of 1-octene using tert-butylhedroperoxide as an oxidant, the Ti(M12.5)-SBA shows the highest catalytic performance, conversion of 1-octene is 47%.The synthersis of organic functional Ti-containing molecular sieves are discussed in chapter 3 and chapter 4. In chaper 3, the organic founctional Ti-containing molecular sieves can be assemed by using a single inorganic TiCl3 as titanium source and tetraethoxysilane and 1,2-bis(triethoxysilyl)ethane as the silica soures and triblock copolymer as the struture-directing agent through hydrothermal methode. The nanocomposites have the highly ordered 2-D hexagonal mesostructure, high surface areas, large pore volumesand large pore diameters. The Uv-vis and FT-IR technique, indicate that the pore walls are composed of polymer, silica and Ti species. The highest catalytic cinversion (62%) of 1-octene in epoxidation is realized on an organic founctional Ti-containing molecular sieve(Ti(S6.7)-SBA).In chaper 4, highly ordered mesoporous bifunctional nanocomposite Ti-SiO2-Polymer have been successfully synthesized by the evaporation-induced co-assembly method, wherein soluble resol polymer is used as an organic precursor, tetraethoxysilane as silica source, and triblock copolymer as the struture-directing agent. The nanocomposites have the highly ordered 2-D hexagonal mesostructure, high surface areas, large pore volumes and large pore diameters. The XPS and FT-IR technique, indicate that the pore walls are composed of polymer, silica and Ti species. These bifunctional nanocomposite: Ti-SiO2-Polymer show remarkably catalytic avtivity in the epoxidation of 1-octene using tert-butylhedroperoxide as an oxidant,the hightest conversition of 1-octene can achive 62%.In the last chapter,we prepared the Ti-containing molecular sieves through postsynthesis. Rapid introduce the titanium into as - made SBA-15 occluded with template. These Ti-containing molecular sieves show excellent catalytic avtivity in 1-octene eopoxidation reaction, the hightest conversition of 1-octene can achive 65%.更多还原