多级结构中空纳米纤维负载金基双金属催化剂的可控合成及其应用研究

贵金属纳米催化剂具有较高的催化活性和选择性，但是由于纳米粒子在催化反应过程中容易发生团聚，及难以分离回收并重复使用等缺点，限制了其实际应用。本项目拟采用静电纺丝和水热/溶剂热技术相结合的方法，设计合成一种具有多级结构特征的硅酸盐中空纳米纤维网毡，构筑具有超大比表面积的催化剂载体，通过简单温和的方法在载体上实现对金基双金属纳米粒子尺寸、组成和负载量的可控负载，将该复合催化剂应用于醇氧化催化性能的研究。利用硅酸盐这种独特的网毡结构，提高复合纳米催化剂的可分离和重复使用性能。研究具有多级结构中空纳米纤维的形成机理；探索催化剂与载体之间相互作用机理；通过对复合纳米催化剂的结构和组成、催化性质及循环稳定性等方面的测试分析，揭示载体和双金属纳米粒子对催化活性、选择性和稳定性的影响规律和催化机理。为实现设计合成具有高催化活性，同时又具有良好循环使用性能的负载型双金属纳米催化剂提供理论基础和实验数据。

Noble-metal nanoparticles (NPs) have been used as catalysts in various chemical reactions due to their high catalytic activity and selectivity. However, smaller NPs aggregate very easily, resulting in a remarkable reduction in their catalytic activities, and also smaller NPs are hard to be removed from the reaction media and recycled, which limits their applications. The project intends to synthesize the extra long hollow metal silicates nanofibers with hierarchical structures through hydrothermal/solvothermal and electrospinning method, construct the metal silicates nanofibers with high specific surface area as the support for noble metal catalysts. The highly dispersed Au-based bimetallic nanoparticles with controlled size, composition and loading amount will be immobilized on the surface of metal silicates by an easy and mild way, the catalytic properties of the obtained nanocomposites catalysts for the alcohol oxidation will also be investigated. The silicates with unique nanofibers network structure could improve the performance of nanocomposites catalysts for separation and reuse. In this project, the growth mechanism of hollow nanofibers with hierarchical structures will be revealed. The interaction mechanism of the nanoparticles catalysts and the supports will be explored. The structure and composition of nanocomposites, catalytic properties and recycling properties will also be investigated, in order to reveal the effects of supports and bimetallic nanoparticles on the activity, selectivity and stability of the nanocomposites catalysts. The research of this subject is expected to give a theoretical and experimental foundation for designing and fabricating new nanocomposites catalysts with high catalytic activity and good performance of separation and reuse.