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氧化铈(CeO2)是一种重要的催化材料,在环境催化和催化氧化等诸多领域表现出了出色的催化性能。将其他金属离子引入氧化铈晶格通过电荷平衡原理诱导产生丰富的氧空位,是提高氧化铈催化性能的有效方法。当Fe3+进入CeO2晶格时,由于其离子半径较小,可同时形成取代和间隙两类固溶体,取代与间隙位Fe3+的摩尔比决定着氧空位的浓度,这使铈铁复合氧化物上的氧空位浓度极具调变性。另外,由于氧化铁本身亦对某些反应具有催化活性,游离的氧化铁与氧化铈颗粒间形成的特殊界面也表现出了优异的催化特性。铈铁间多重的协同作用使这类复合氧化物具有较高的研究和使用价值。本文介绍了铁离子在氧化铈中的固溶度和氧空位调变性等铈铁复合氧化物的结构特点,探讨了该材料的结构对其制备条件的敏感性,概述了其在催化领域的应用,并讨论了铈铁交互作用在催化过程中的作用。结合本课题组的一些研究成果,指出了铈铁材料尚未解决的一些关键问题和可能的研究方向。
Cerium oxide (CeO 2) is an important catalytic material that shows excellent catalytic performance in many fields such as environmental and catalytic oxidation. The introduction of other metal ions into the cerium oxide lattice induces rich oxygen vacancies through the charge balance principle, which is an effective method to improve the catalytic performance of cerium oxide. When Fe3 + enters the CeO2 lattice, the two kinds of substitutional and interstitial solid solutions can be formed at the same time due to its smaller ionic radius. The molar ratio of substitution to interstitial Fe3 + determines the concentration of oxygen vacancies. This makes the oxygen on the cerium iron composite oxide Vacancy concentration is highly variable. In addition, since iron oxide itself is also catalytically active for certain reactions, the special interface formed between free iron oxide and cerium oxide particles also exhibits excellent catalytic properties. The multi-synergistic effect between cerium and iron makes the composite oxides of higher research and use value. In this paper, the structural characteristics of cerium-iron composite oxides, such as the solid solubility of iron ions in ceria and the oxygen vacancy modulation, are introduced. The structure of the material is also discussed for its sensitivity to the preparation conditions and its application in catalysis , And discussed the role of cerium-iron interaction in catalysis. Based on some research results of our group, some key problems and possible research directions have not been solved yet.