特定形貌和多孔纳米CeO_2的制备及其CO催化氧化研究进展

Preparation and catalytic oxidation of CO with specific morphology and porous nano CeO_2

Ce是一种用途十分广泛的稀土金属,其金属氧化物Ce O_2由于具有优异的储放氧性能,使其在氧化还原、有机合成和有机污染物降解等反应过程中呈现出良好的催化性能,尤其是在CO的催化氧化反应中表现出了优异的活性。本文综述了纯Ce O_2及复合Ce O_2催化剂的制备方法、形貌与孔道控制及其对CO催化氧化性能等方面的最新研究进展。首先介绍了液相法、固相法和气相法等不同合成纳米Ce O_2的方法,通过对不同制备方法的工艺、成本、合成条件分析对比后,对其优缺点进行了系统的总结。随后讨论了利用不同制备方法及添加不同表面活性剂或模板剂所制备出的特定形貌及多孔纳米Ce O_2催化剂对CO的催化氧化性能,描述了Ce O_2对CO催化氧化的作用机理及形貌结构对催化性能的影响。最后根据对相关结果的总结发现,特定形貌及多孔结构的纳米Ce O_2催化CO活性虽有提高,但存在结构不稳定、工艺复杂等问题。而且,对于催化反应过程中的反应机理,形貌与结构变化的研究较少。希望在今后的工作中简化制备工艺,提高Ce O_2材料结构的稳定性,并用原位表征、模拟计算等方法来探究CO的氧化机理。

Ce is a very versatile rare earth metal and its metal oxide CeO2showed good catalyticperformance in redox reaction,organic synthesis and degradation of organic pollutants due to itsexcellent oxygen storage capacity,especially in the catalytic oxidation of CO.This paper introduces thelatest research progress on the preparation methods,morphology and channel control of pure CeO2andCeO2composite catalyst and their catalytic oxidation of CO.Firstly,this paper introduces differentsynthesis methods of nanometer CeO2from the aspects of process,cost,and the synthetic conditionsand summarizes their advantages and disadvantages.Then this paper discusses the nanometer CeO2catalyst with specific morphology for catalytic oxidation of CO performance,describes the catalyticmechanism and the influence of the morphology on the catalytic performance.It was found that thecatalytic activity of nano-CeO2with specific morphology and porous structure was improved,but thestructure was unstable and the process was complicated.Moreover,there are few studies on thereaction mechanism,morphology and structure change during the catalytic reaction.It is demanded that the preparation process can be simplified in the future work to improve the structure stability of CeO2andthe oxidation mechanism of CO will be explored using in situ characterization and computer simulation.