采用石墨还原法成功制备了烧绿石型富氧相Ce2Zr2O8,选用缺氧型烧绿石Nd2Zr2O7作为Ce2Zr2O8相前驱体CeZrO3.5的替代物与之进行结构对比分析.实验结果表明:Ce2Zr2O8相中富余氧主要占据前驱体中的氧空位,且氧离子扩散不会破坏原本有序排列的阳离子(Ce/Zr)亚点阵;同时,Ce2Zr2O8相中Zr-O配位体由前驱体中共项联接的八面体转变为共棱联接的立方体,其反相畴界密度和振动光谱谱带亦较前驱体明显提高.以上结果说明Ce2Zr2O8相结构处于亚稳态,该结构特征有利于氧离子的快速吸附或释放,这为其成为汽车尾气净化剂提供了结构上的可行性,但也说明当An2Zr2O7烧绿石在自辐照条件下向富氧相An2Zr2O8发生转变时,其抗辐照和化学稳定等性能有下降趋势.
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