微/介孔Pd-MOFs@有序硅复合材料原位吸附/催化典型VOCs性能及机理研究

Recently, the application of adsorption/catalytic oxidation coupling technology in the local environment air purification is widespread throughout the world. At present, the preparation of materials with high BTX (benzene, toluene and o-xylene) adsorption capacities and properly desorption temperatures and high dispersion of metal nanoparticles is of great significance in highly efficient abatement of BTX at low temperatures by in-situ adsorption/catalytic oxidation technology. Based on characteristic of metal organic frameworks (MOFs) materials’ large microporous capacities and mesoporous silica materials’ ordered channel, highly uniformly small sized cheap Pd nanoparticles in the platinum group as active species, are supported on micro/mesoporous MOFs@ordered silica composite materials. The synthesis of Pd catalysts solves some key problems of low BTX adsorption capacities and desorption temperatures and poor dispersion of metal nanoparticles, aiming at achieving a high catalytic activity for BTX oxidation at low temperatures. The relation between BTX adsorption/desorption, the catalytic activity for BTX oxidation and the physical characters of nanosized Pd catalysts are expounded on in the research. In addition, BTX oxidation reaction mechanism of MOFs system and the synergy between the frameworks metal ions and Pd species are also discussed, which provide the experimental and theoretical basis for preparing highly efficient adsorption/catalytic oxidation bi-functional MOFs@ordered silica catalysts for local environment VOCs abatement at low temperatures.

近年来，吸附/催化联用技术被世界各国广泛用于净化居室、生产车间、公共场所等局部环境空气。目前，开发对苯系物吸附能力较高、脱附温度适当以及活性组分高度分散的材料，对原位吸附/催化技术低温去除典型VOCs中的苯系物具有重要的意义。本研究以实现低温高效去除苯系物为最终目的，利用金属有机骨架材料（MOFs）微孔容量大以及介孔硅材料孔道有序的特点，选用铂族中廉价的钯作为活性组分，制备高度均一小尺寸的钯粒子分散在微/介孔MOFs@有序硅复合材料上，从根本上解决了苯系物吸附量和脱附温度低、金属粒子分散性差的关键问题。通过研究纳米钯催化剂微观结构与苯系物吸/脱附、低温催化氧化性能之间的内在规律，阐明苯系物氧化反应机理及MOFs骨架金属离子和钯物种之间的协同作用，为开发基于MOFs@有序硅复合材料的低温高效消除局部环境VOCs的吸附/催化双功能催化剂提供实验和理论基础。