Comparison of the microstructure and oxygen storage capacity modification of Ce0.67Zr0.33O2 from CaO and MgO doping
Comparison of the microstructure and oxygen storage capacity modification of Ce0.67Zr0.33O2 from CaO and MgO doping
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DOI：
10.1016/j.jallcom.2006.09.110
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发表时间：
2007-08
影响因子：
6.2
通讯作者：
Y. An;Meiqing Shen;Jun Wang
中科院分区：
文献类型：
--
作者：
Y. An;Meiqing Shen;Jun Wang
比较了CaO和MgO的掺杂对Ce0.67Zr0.33O2微观结构和动态储氧能力(OSC)的影响。 XRD、拉曼光谱和HRTEM观察证实，MgO和CaO掺杂后，由于电荷补偿和半径效应，萤石晶格中产生了更多的氧离子空位和晶格缺陷。另一方面，通过掺杂获得了改进的相热稳定性。动态OSC测量结果表明，MgO和CaO掺杂增强了Ce0.67Zr0.33O2的动态OSC。但经过氧化还原处理后，两种掺杂剂之间发现了差异。 CaO掺杂的OSC的改善归因于适当的离子半径和有效的微观结构修饰。氧化还原处理后MgO掺杂Ce0.67Zr0.33O2的OSC降低是由于Mg2+在二氧化铈晶格中溶解度小以及Mg-Ce-Zr-O体系缺陷结构的塌陷所致。
Doping effect of CaO and MgO on the microstructure and dynamic oxygen storage capacity (OSC) of Ce0.67Zr0.33O2was compared. XRD, Raman spectra and HRTEM observation confirmed that after MgO and CaO doping, more oxygen ion vacancies and lattice defect in the fluorite lattice were produced due to charge compensation and radius effect. On the other hand, improved phase thermal stability was obtained from doping. Results of dynamic OSC measurements showed that MgO and CaO doping enhance the dynamic OSC of Ce0.67Zr0.33O2. But after redox treatment difference was found between the two dopants. The improved OSC of CaO doping was due to the proper ionic radius and effective modification of microstructure. The decreased OSC of MgO doped Ce0.67Zr0.33O2after redox treatment was due to the small solubility of Mg2+in ceria lattice and collapse of the defective structure of Mg–Ce–Zr–O system.