离子热法设计合成硅锗酸盐化合物及其性质的研究

Because of their excellent catalytic property, molecular sieves materials have been widely used for the synthesis of fine chemicals in the field of petroleum industry. With the development of molecular sieve materials, new molecular sieves of germinates has gained much more attention in recent years due to their unmatched large porosity as compared to the traditional molecular sieves of aluminosilicates. Despite germinates exhibit the largest pore structure more than 20Å and excellent adsorption ability, the drawbacks such as less structural diversity, poor thermodynamic stability limit its application for catalysis. The introduction of silicon element into the germinate framework has been proven an effective method to improve the thermodynamic stability of germinates, therefore the study of germanosilicates is becoming hot spot. Different from the traditional hydrothermal method, ionothermal synthesis method using ionic liquid as solvent has shown great potential on the synthesis of phosphate and silicate zeolites. Ionic liquids are a family of non-conventional molten salts comprising various anions and cations. It can act not only as solvents for the syntheses of inorganic compounds but also as structure-directing agents (SDA) and/or template precursors. In contrast to the traditional solvents of water and alcohols used in the syntheses of inorganic molecular sieves, ionic liquid is an ideal “designable” solvent because of its unique characters such as low melting point, low vapor pressure, reusability and rich categories, etc. The purpose of this program is to prepare novel molecular sieve materials of germanosilicates and metal-germanosilicates by the newly developed ionothermal synthesis method under the guidance of rational designed organic templates. Furthermore, the catalysis and adsorption processes would be investigated by experimentation and theoretical calculation.

分子筛材料的优异催化特性使其在石油化工等精细化学品行业取得了广泛的应用，随着分子筛材料的发展，具有比传统硅（磷）铝酸盐分子筛更大孔道结构的锗酸盐分子筛在近年得受到关注，尽管锗酸盐分子筛展现了20Å以上的超大孔道和良好吸附性能，但是其仍然存在结构种类少、热力学稳定性不高等问题。硅锗酸盐分子筛提高了其热稳定性，研究其吸附催化性质等工作正逐渐成为热点。不同于传统水热法，离子液体作为溶剂的离子热合成方法已经在硅（磷）酸盐分子筛类材料的合成中展现了巨大的潜力。离子液体是一种以阴阳离子配位形式存在的非传统熔融盐，其不仅可以作为溶剂，还可以作为无机材料的模板剂和前驱体。它不同于水和醇溶剂，离子液体具有低熔点、高沸点、可循环利用等特征。本项目旨在利用新近发展的离子热合成方法，通过设计模板剂制备出一系列硅锗酸盐分子筛及金属掺杂的硅锗酸盐开放骨架材料，对其吸附、催化等性质进行研究，并通过理论计算进行模拟比对。

本项目主要以过渡金属以及过渡金属掺杂的磷酸盐或者亚磷酸盐开放骨架化合物的合成与性质研究为目标，通过水热，溶剂热和离子热法等技术进行该类化合物的合成，通过高通量技术结合结构设计理念研究合成条件对晶体结构的影响，结合实验与计算结果深入研究所合成物质的物理化学性质。此外，我们也在项目资助下进行了过渡金属构筑的金属有机骨架（MOF）材料的设计合成及性质研究和当前广泛关注的二维材料和金属催化剂晶面小分子的选择性催化反应等课题进行了理论计算的研究。本项目的完成为具有优越性质材料的开发提供了一定实验和理论基础。