A Joint Theoretical and Experimental Study of Phase Equilibria and Evolution in Pt-Doped Calcium Titanate under Redox Conditions
A Joint Theoretical and Experimental Study of Phase Equilibria and Evolution in Pt-Doped Calcium Titanate under Redox Conditions
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氧化还原条件下铂掺杂钛酸钙相平衡和演化的联合理论与实验研究
DOI：
10.1021/cm5022239
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发表时间：
2015
影响因子：
8.6
通讯作者：
X. Pan
中科院分区：
文献类型：
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作者：
Baihai Li;M. Katz;Y. Duan;Xianfeng Du;Kui Zhang;L. Chen;Anton Van der Ven;G. Graham;X. Pan
利用第一线原理理论方法构建了pxo - cao - tiox体系的赝三元相图，解释了用扫描透射电子显微镜观察到的掺杂pt的CaTiO3的相形成和演化过程。在该体系中，Pt作为自再生的汽车尾气催化剂，在还原条件下从掺杂的钙钛矿中析出金属颗粒，在氧化条件下倾向于再溶解。由于动力学限制对实验观察的可能影响，我们将重点放在一个受限（亚稳态）相图上，其中有意排除了单个和其他未观察到的Pt氧化物。然而，出现了各种钛酸盐相，它们的存在有助于为相图的计算提供信息，这反过来又证实了自再生效应是在所研究的特定氧化还原环境下热力学相稳定性的结果。
Pseudoternary phase diagrams of the PtOx–CaO–TiOx system were constructed using first-principles theoretical methods to interpret experimental observations of phase formation and evolution in Pt-doped CaTiO3 made by aberration-corrected scanning transmission electron microscopy. In this system, promoted as a self-regenerative automotive exhaust-gas catalyst, Pt precipitates as metallic particles from the doped perovskite under reducing conditions and tends to redissolve under oxidizing conditions. Due to the likely influence of kinetic limitations on experimental observations, we focus on a restricted (metastable) phase diagram in which single and other unobserved oxides of Pt are intentionally excluded. Various titanate phases appear, however, and their presence helps inform the calculation of the phase diagrams, which in turn confirm that the self-regenerative effect is a consequence of thermodynamic phase stability under the specific redox environments examined.
影响因子：
--
作者：
Hirohisa Tanaka;M. Taniguchi;M. Uenishi;Nobuhiko Kajita;Isao Tan;Y. Nishihata;J. Mizuki;K. Narita;M. Kimura;K. Kaneko
通讯作者：
Hirohisa Tanaka;M. Taniguchi;M. Uenishi;Nobuhiko Kajita;Isao Tan;Y. Nishihata;J. Mizuki;K. Narita;M. Kimura;K. Kaneko