高体积比表面积蜂窝状纤维多孔陶瓷催化剂载体的结构与性能调控研究

This project pay close attention to the imperious demands of our society, which are increasing the effluent standard of automobile exhaust and steep demand of cleaning catalyst carriers in the field of haze treatment. This project comes up with a thought that one-dimensional fibers, crystal whisker and two-dimensional nanosheet composite on multi dimension. This project study on in-situ growth of nanosheet on fibers surface, structure and properties control of honeycomb fibrous porous catalyst support ceramics. The research contents includes: The research focus on the key technology of in-situ growth of nanosheet on fibers surface and the mechanism of interface bonding and strengthening. Study the rules of ratio, combination mode and other factors of one-dimensional fibers, crystal whisker and two-dimensional nanosheet effect on mechanical property, unit volume specific surface area and flow resistance of honeycomb fibrous porous ceramics. Investigate the theory and key control technology of damaged of fibers at high temperature by designing the grain boundary and controlling the grain growth. Study the rules of the properties of honeycomb fibrous porous ceramics effect on load capacity of catalyst and catalytic activity. The project could get a high unit volume specific surface area, low thermal capacity, long lifetime, high catalyst load capacity novel catalyst support ceramic material. The study of this project would offer a new way to clean and reduce the emission of automobile exhaust and flue gas of high temperature industry. Besides this, it has great significance to the theoretical research and technological development of high properties and long lifetime fiber materials.

本项目针对雾霾治理中汽车尾气排放标准提高和对汽车尾气净化催化剂载体提出的更为苛刻要求的迫切需求，提出采用一维纤维、晶须和二维纳米片多维度复合，开展纳米纤维表面原位生长纳米片及蜂窝状纤维多孔陶瓷催化剂载体的结构与性能调控研究。探讨纳米纤维表面原位生长纳米片的关键制备技术及其界面结合与强化机制；研究一维纤维、晶须和二维片状材料的配比、结合方式等因素对蜂窝状纤维多孔陶瓷力学性能、体积比表面积、过流阻力的影响规律；通过晶界设计和晶粒生长控制，探讨纤维高温使用条件下的抗粉化的理论与关键调控技术；探讨蜂窝状纤维多孔陶瓷性能对催化剂载体的催化剂负载量及催化效果的影响规律。获得一种高体积比表面积、低热容、长寿命、高催化剂负载量的新型催化剂载体陶瓷材料。本项目研究将为汽车尾气和工业高温废气净化减排提供一条新的技术途径，也将对高性能和长寿命纤维材料的理论研究和技术发展具有重要意义。

针对雾霾治理中汽车尾气排放标准的提高和对汽车尾气催化剂载体提出的更为苛刻要求的问题，本项目创新性地提出采用一维微米级Al2O3纤维、纳米级Al2O3纤维、纳米级ZrO2纤维、SiC晶须和二维TiO2纳米片多维度复合制备蜂窝状纤维陶瓷催化剂载体，开展了静电纺丝制备纳米级Al2O3纤维，纤维和晶须表面原位生长TiO2纳米片及蜂窝状纤维陶瓷催化剂载体的制备、结构与性能的研究工作。取得了以下主要结果：.1、采用静电纺丝工艺制备Al2O3、ZrO2、TiO2等多种纳米纤维，优化了制备工艺参数，结果表明以30%Al2O3/DMF分散液为铝源可制备性能较好的Al2O3纳米纤维，直径收缩率仅为22%。.2、采用热液合成工艺制备TiO2纳米片修饰的微米级Al2O3纤维膜，探讨了工艺参数对纳米片生长的影响规律。并研究了在Al2O3纳米纤维、ZrO2纳米纤维和SiC晶须基体表面原位生长TiO2纳米片的工艺，在经过优化的工艺参数下，TiO2纳米片均能实现在同质和异质基体表面的生长。.3、采用浆料成形—高温固化—热液合成工艺制备了TiO2纳米片修饰的级配Al2O3纤维陶瓷催化剂载体，获得了优化的制备工艺。以硅溶胶为结合剂，采用浸渍-溶剂热法，可获得具有低的体积密度0.48g/cm3，高的比表面积7.84m2.g-1（ 37.9×103 cm2/cm3 ），抗压强度为2.01MPa的TiO2纳米片修饰的级配Al2O3纤维陶瓷催化剂载体。TiO2纳米片的表面生长可以有效提高纤维多孔陶瓷的力学性能和体积比表面积。.4、蜂窝状纤维陶瓷催化剂载体在热冲击温度为800℃时仍能保持很好的稳定性；常温气流冲蚀12h载体基本无质量损失，高温（800℃）气流冲蚀4h后趋于稳定，质量不再变化。.5、获得了优化的贵金属催化剂的浸渍工艺和热处理温度的工艺，负载贵金属催化剂的蜂窝状纤维多孔陶瓷的催化起燃温度可低达160℃左右，200oC以下对氢气的转化率可达为75%。.本项目研究的具有高体积比表面积、低热容、低起燃温度的新型催化剂载体陶瓷材料将为汽车尾气和工业高温废气净化减排提供一条新的技术途径，也将对高性能和长寿命纤维材料的理论研究和技术发展具有重要意义。