【作者】 陈国华；

【导师】 贾明君； 张文祥；

【作者基本信息】 吉林大学 ， 物理化学， 2009， 硕士

【摘要】 磷酸铝分子筛的出现,开创了微孔材料新的历史纪元。由于其具有中性骨架,可以加入其它组分来形成材料的酸碱或者氧化中心,因而合成这类材料备受瞩目。在分子筛的合成过程中,模板剂起着重要作用。具有AFI结构的APO-5是磷酸铝材料中最具代表性的,合成该分子筛的模板剂比较多,没有这些模板剂存在就不能形成特定的结构。因此尝试其他不同结构的模板剂来合成新结构的材料也是科研工作者的课题之一。本文主要介绍合成了几类双季铵碱类化合物,并以此为模板剂合成磷酸铝分子筛,考察了各类合成条件的影响。实验结果表明双季铵碱模板剂(C2H5)3N+(CH2)nN+(C2H5) 3能导向形成典型的AFI结构的分子筛,而且在多种杂原子取代的磷酸铝分子筛中也同样具有良好的导向性。另外,我们还初步考察了氮甲基咪唑类和氮甲基吡咯类双季铵盐模板剂下微孔磷酸铝分子筛的合成,也取得了一些有意义的结果。随着磷酸铝分子筛合成研究的深入,其在催化反应中的应用价值越来越大。在本文中,我们继续探索了含杂原子磷酸铝分子筛的合成,并将其用于邻苯二酚和甲醇单醚化反应。结果表明,溶剂热合成的磷酸铝分子筛具有较水热合成的材料更好的催化活性。同时发现,通过催化性能评价,由于杂原子种类的差异,不同杂原子取代的磷酸铝分子筛在该反应中的酸碱性能明显可调。此外,为了进一步提高纯磷铝二组分分子筛的催化性能,我们还制备了负载型磷酸铝分子筛催化剂。结果表明,以磷酸修饰的二氧化硅为载体时,可以使得负载型磷酸铝分子筛在该反应中的催化活性有所提高。本文阐述了双铵类化合物在不同条件下磷酸铝微孔材料的合成,加深了模板剂的引导作用的认识,为进一步合成新模板剂在磷酸铝分子筛合成中的应用奠定了基础。更多还原

【Abstract】 Microporous materials with high specific surface area, uniformity pore size distributions and high hydrothermal stability, therefore were used widely in many fields, such as adsorption and separation, ion exchange and host-guest chemistry. In the catalytic industry, they can also be used as catalysts and catalyst carriers. Since people the first time found the natural zeolite structure of porous materials, the synthesis and applications of microporous materials obtained a series of great achievements. Early studies on natural zeolite were mainly on the structure and nature of knowledge . Researchers found a lot of different structure materials. During 1940s chemist of zeolite the first time imitated the vegatl environment of natural zeolites and synthesized low Si-Al ratio of zeolites under the hydrothermal conditions. In the early 1980s the researchers successfully synthesized a new family of molecular sieve - aluminophosphate molecular sieve, which is not a class of porous silicon compounds. It was an important milestone in the history of the microporous material development .The frameworks of AlPO4-n family are the same amount of aluminum from tetrahedral oxygen tetrahedron composed of oxygen and phosphorus, so its crystal skeleton is neutral which have non-acid centers in the surface and only weak catalytic properties. In the aluminophosphate molecular sieve,the oxygen from the aluminum phosphate composition interconnected skeleton, which in addition to aluminum ion tetrahedral coordination with oxygen. The oxygens are five-coordinate structure of hexa-coordinate, so the structure with a large range of adjustable quality. The appearance of aluminophosphate molecular sieves has greatly enriched the microporous materials at the chemical composition and skeletal structure. Scientific personnel who research in the synthesis of such materials started a lot of work,they found that it needs the participation of the template in the synthesis process before the formation of pore structure. APO-5 molecular sieve which has a AFI skeleton structure is one of the most representative material, as many as 85 kinds of organic compounds can be synthesized as a template to get the material. Because of its neutral framework, the material of the skeleton structure could be changed by adding different metal, which has been widely concern.In this paper we hydrothermaly synthesize that possess AFI framework molecular sieves by useing diquaternary ammonium as SDA and characterized their structures by spectroscopy methods.The catalytic property is evaluated in the selective O-methylation of catechol. From above research,the detailed results is as follows:1 APO-5 materials are synthesized by diquaternary ammonium and we check the impact of different aluminium sources .The framework of molecular sieves are very steady when isopropylate aluminum as the aluminium source without adding HF.The framework collapse after be calcined when aluminum hydroxide as aluminium source. The structure is dense after phosphite as phosphorus source. The phases of material are weakening after increase water content.When the P / Al≠1, there are a few other phases in the molecular sieves. We try to enhance the synthesis of diquaternary ammonium phosphate of aluminum materials through different synthesis methods.2 We add Mg or Si to the initial gel in order to form acid-base centers. In this part of experiment, we use isopropanol aluminuml as the aluminum source of aluminum without adding HF.As the Mg / Al is lower than 0.1, the crystal exist AFI phase steadily, when Mg / Al higher than 0.1, the crystal generate other phase. It needs to add HF in order to maintain the structure of crystalline phase alumina aluminum source when alumina as aluminum source. Later we dop the Ti or Sn to the gel. The results show that two atoms can access to the skeleton very well. 3 We simply synthesize different transition metal zeolites by changing the temperature and amount of template. The material which have Co or Mn can easily form AFI structure and Fe or Cr is more difficult to enter the framework. We can note that there are some flaws when diquaternary ammonium in guiding the transition metal to form microporous material.4 We evaluate catalytic property of the materials that are synthesized by Et3N in the O-methylation of catechol.These material display a certain degree of reactivity and this can explain the existence of acid-base center in the molecularsieves and also evaluate catalytic property of the materials that are synthesized by diquaternary ammonium in the Oxidation of Cyclohexane.5 We change the two-branched-chain structure of diquaternary ammonium, and used these organic compounds as templates to synthesize aluminophosphate microporous molecular sieves.更多还原