尖晶石型催化剂的制备及在气态污染物净化中的应用综述

Spinel Catalysts: Preparation Technology and Applications in Catalytic Purification of Gaseous Pollutants

催化净化法是气态污染物净化的主要技术之一,在改善和优化人类的生存环境质量方面发挥了至关重要的作用。随着科研人员不断深入的研究,开发高比表面积、高效率、短反应物/产物扩散途径以及低能耗的催化材料是目前催化技术领域的研究重点。按催化材料成分分类,一般催化剂可分为过渡金属催化剂、金属氧化物催化剂、硫化物催化剂、固体酸催化剂等。传统金属氧化物催化剂受本身固有结构、活性氧物种及暴露活性位点较少等物理化学性质的限制,难以突破可调控性较差、催化效率较低的瓶颈。研究表明,由特殊的四面体和八面体结构相间组成的尖晶石型金属氧化物因具备结构、组分、物相、价态、形貌和缺陷的可调控性,表现出优异的超导性、发光性、催化活性等理化特性,在介电、磁性、发光、催化等功能材料应用领域中占据重要地位,被视为极具研究与应用潜力的一种高效气态污染物的新型催化净化材料。在催化剂制备合成方法中,沉淀法、水热法为常见的制备方法。然而,传统合成方法已经不能满足人们对不同形貌、构型、多组分复合催化剂的制备需求。为制备可调控性强、物理化学性质优异的尖晶石型催化剂,导晶沉淀、微波辅助水热、自组装法等新型复合制备方法受到人们的广泛关注。Mn、Co、Fe、Cr等尖晶石型催化剂被应用于气态污染物的脱除,其中Mn、Co尖晶石型催化剂因自身价态多变、氧化还原能力强而具有较高的催化去除效果及稳定性,从而被人们广泛研究。本文归纳了尖晶石型催化剂的研究进展,分别对尖晶石型催化剂的空间结构特性、典型制备方法的合成机制等进行介绍,重点分析其在气态污染物催化净化方面的发展方向并展望其前景,并对其未来的理论和应用研究给出了建议。

Catalytic purification is one of the main technologies for the purification of gaseous pollutants,which plays an important role in improving andoptimizing the quality of human living environment. With the continuous in-depth research of scientific researchers,the development of catalytic materials with high specific surface area,high efficiency,short reactants/product diffusion path and low energy consumption is the key point of current catalytic research.According to the composition of catalytic materials,general catalysts can be divided into transition metal catalyst,metal oxide catalyst,sulfide catalyst,solid acid catalyst,etc. Traditional metal oxide catalysts are limited by physical and chemical properties such as inherent structure,species of reactive oxygen and less active sites exposed,it is difficult to break through the bottleneck of poor controllability and low catalytic efficiency.Research has shown that spinel metal oxide which made up of special tetrahedral and octahedral structure and composition showing excellent physical and chemical properties such as superconductivity,luminance,catalytic activity due to their controllability of structure,component,phase,valence state,morphology and defects. It occupies an important position in the application fields of dielectric,magnetic,luminescent,catalytic and other functional materials,and is regarded as a new type of highly efficient catalytic purification material for gaseous pollutants with great research and application potential.Precipitation and hydrothermal methods are the common preparation and synthesis methods for catalyst synthesis. While the traditional synthesis methods are no longer meet the preparation needs of composite catalysts with different morphologies,configurations and multi-component. In order to prepare spinel type catalyst with strong controllability and excellent physicochemical properties,new composite preparation methods such as crystal conducting precipitation,microwave-assisted hydrothermal and self-assembly have attracted extensive attention. Mn,Co,Fe,Cr and other spinel type catalysts have been applied in the removal of gaseous pollutants,among which Mn and Co spinel type catalysts were being widely studied for their high catalytic removal efficiency and stability due to their variable valence and strong redox ability.This paper summarizes the research progress of spinel catalyst,the structure characteristics of spinel type catalyst and the synthesis mechanism of typical preparation methods are introduced separately,and the development direction of catalytic purification of gaseous pollutants and its prospects are emphatically analyzed. Suggestions for its future theoretical and applied research are given.