稀土催化剂(Ce、La)用于丙烷催化燃烧的研究进展

Advances in Rare Earth Element-based Catalysts(Ce,La)for Propane Catalytic Combustion

目的挥发性有机物(VOCs)对人体健康和生态环境都有不良影响,已引发研究者的广泛关注。催化燃烧是处理VOCs的有效技术之一,具有去除效率高、无二次污染等优势。稀土元素Ce、La及其氧化物因特殊的理化性质常作为催化助剂或载体,在催化燃烧中起着重要作用。因此针对稀土催化剂(主要为Ce、La),综述了其在丙烷催化燃烧中的应用及相应的催化反应机制以及未来的发展方向。方法通过对Ce基和La基催化剂在丙烷催化燃烧中的研究和应用进行综述,分析了稀土催化剂的反应机理及发展方向。结果首先,Ce、La及其氧化物可调节催化剂的整体结构、形貌和比表面积等物理性质;同时,上述物质也可与催化剂内的其他金属相互作用,从而有效调控材料中的氧空位密度,最终增强对丙烷催化燃烧的反应活性。其次,CeO_(2)作为载体能与活性金属产生有赖于CeO_(2)形貌和晶面的金属-CeO_(2)相互作用,这会对催化剂的结构和性能产生极大影响。此外,也讨论了通过优化合成方法和表面改性所获得的La系钙钛矿催化剂在丙烷催化燃烧中的应用研究。结论目前,稀土基催化剂的催化作用机制探索尚处于初级阶段,应对其进行更深入系统的研究,以早日实现其工业化应用。

Objective Volatile organic compounds(VOCs)have adverse effects on both human health and the ecological environment,thus attracting widespread attention from researchers.Catalytic combustion is one of the effective technologies for treating VOCs,with the advantages of high removal efficiency and no secondary pollution.Rare earth elements such as Ce and La and their oxides often play an important role in catalytic combustion due to their special physicochemical properties as catalytic additives or carriers.Therefore,for rare earth catalysts(mainly Ce and La),their applications in the propane catalytic combustion and the corresponding catalytic reaction mechanisms as well as future development directions were reviewed.Methods Through a review of the research and applications of Ce-based and La-based catalysts in the propane catalytic combustion,the reaction mechanisms and development directions of rare earth catalysts were analyzed.Results Firstly,Ce,La,and their oxides modulated the physical properties of the catalyst such as the overall structure,morphology,and specific surface area.Meanwhile,these substances also interacted with other metals within the catalyst to effectively modulate the oxygen vacancy density in the material,ultimately enhancing the reactivity for the propane catalytic combustion.Secondly,when CeO_(2) acted as a carrier,it was capable of producing metal-CeO_(2) interactions with the active metal dependent on the CeO_(2) morphology and crystallographic surface,which can have a great impact on the structure and performance of the catalyst.Studies on the application of La-based chalcogenide catalysts obtained by optimizing synthesis methods and surface modification in the propane catalytic combustion were also discussed.Conclusion At present,the exploration of the catalytic mechanism of rare earth-based catalysts is still in its initial stage,and in-depth and systematic research should be conducted to realize its industrial application as early as possible.