“动态模板”法可控构筑多级孔硅氢化合物材料及其作为贵金属催化剂载体的应用研究

项目名称： “动态模板”法可控构筑多级孔硅氢化合物材料及其作为贵金属催化剂载体的应用研究

项目编号： No.21501056

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 李娜

作者单位： 湖南工业大学

项目金额： 20万元

中文摘要： 本项目旨在建立一种多级孔HSQ材料可控构筑的新方法，并研究多级孔HSQ材料作为贵金属催化剂载体的应用。为此，拟采用“动态模板”方法，即以聚环氧乙烷-b-聚4-乙烯苯基-N,N’-二乙基胺盐酸盐嵌段共聚物为阳离子聚电解质，N-十二烷基肌氨酸钠为阴离子表面活性剂，利用m-PEO-b-PVEAH与Sar-Na形成的介晶复合物为模板，制备多级孔HSQ材料。通过系统研究，阐明多级孔HSQ材料的合成机制，探索出一条多级孔HSQ材料可控构筑的新方法。以多级孔HSQ材料为载体和还原剂，研究贵金属纳米催化剂在其孔道内部的固载情况，开发一种简单高效的负载型贵金属纳米催化剂的制备体系。以水相中硝基苯的催化氢化为模型反应，考察负载型贵金属催化剂的催化性能，揭示多级孔HSQ材料在贵金属纳米催化剂负载中载体材料与催化性能之间的构效关系，拓展HSQ材料在催化领域中的应用。

中文关键词： 硅氢化合物；多孔材料；模板法；介晶复合物；贵金属纳米粒子

英文摘要： This project aims at the synthesis of hierarchically porous hydridosilsesquioxane (HSQ) materials and their application as scaffold of noble metal nanoparticles. To accomplish our goal, hierarchically porous HSQ materials are firstly synthesized through “dynamic template” of organic mesomorphous complexes formed by polyelectrolyte (poly(ethylene oxide)-b-poly[N-(4-vinylbenzyl)-N,N’-diethylamine hydrochloride] (m-PEO-b-PVEAH)) and cationic surfactant (N-lauroylsarcosine sodium (Sar-Na)). The key of the design involves: 1) the hydrogen bonding between the ether oxygens of m-PEO chain and trialkoxysilane benefits to the stability of the HSQ during the hydrolysis process; 2) the hydrolysis of the trialkoxysilane precursors in acid condition generates positively charged silica oligomers, the inorganic species will disturb the electrostatic interactions between PVEAH chains and the anion surfactants which makes the phase separation of PVEAH chains and therefore forms a dynamic template. In our strategy, the m-PEO chain and the anion surfactants act as the mesoporous template while the phase separated PVEAH domains act as the secondary nanoporous template. The morphologys and meso-structures of the synthesized hierarchically porous HSQ materials originate from the mesomorphous complex of m-PEO-b-PVEAH/Sar-Na. By adjusting the molecular weight, chain length of the polyelectrolyte, the molar ratio of polyelectrolyte and surfactant, and reaction factors such as synthesis temperature, pH value, hierarchically porous HSQ materials with well-defined morphologys and meso-structures and controllable pore size will be prepared and the synthetic mechanism will be revealed.. Ascribe to the inherent Si-H group and the hierarchically porous structure, the synthesized HSQ materials are used as both the scaffolds and mild reducing agent for the immobilization of noble metal nanoparticles. The advantages of the hierarchically porous HSQ materials lie in: first, without using of other reducing agent simplifies the catalyst preparation process; second, the ordered mesopores in HSQ materials can effectively trap and capture the noble metal nanoparticles avoiding the loss of catalyst during the catalytic process; third, the large pores in HSQ materials can act as the warehouse of the reactant which benefit to the concentration of the reactant and therefore enhance the catalytic property. The structure-activity relationship of the morphology, meso-structure and pore size of HSQ materials with the immobilization efficiency and catalytic property of the noble metal nanoparticles will be explored by choosing the catalytic hydrogenation of nitrobenzene in water as a typical example.. This project is anticipated to develop a new strategy for the synthesis of hierarchically porous HSQ materials and offer a potential theoretical guidance for the application HSQ materials in catalysis.

英文关键词： Hydridosilica;Porous Material;Template Method;Mesomorphous Complex;Noble Metal Nanoparticles