Du Zhihong, Gong Yue, Zhao Hailei, Zhang Yang, Yi Sha, Gu Lin
School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Beijing Municiple Key Lab for Advanced Energy Materials and Technologies, Beijing 100083, China.
ACS Appl Mater Interfaces. 2021 Jan 20;13(2):3287-3294. doi: 10.1021/acsami.0c14686. Epub 2021 Jan 5.
Exsolution of catalytic nanoparticles (NPs) from perovskites has arisen as a flexible method to develop high-performance functional materials with enhanced durability for energy conversion and catalytic synthesis applications. Here, we unravel the interface structure of the exsolved alloy nanoparticles from the double perovskite substrate on the atomic scale. The results show that the Co-Fe alloy NPs exsolved topologically from the {100} facets terminations of the SrFeMoCoO (SFMC) double perovskite along ⟨100⟩ directions exhibiting the same orientation and identical crystal structure. The lattice planes of these two phases align and insert into each other at the interface, forming a smooth and continuous coherent connection. The presence of moiré patterns at the interface confirms the topological exsolution mechanism. The coherent interface can significantly reduce the interfacial energy and therefore stabilize the exsolved nanoparticles. Therefore, excellent and stable electrochemical performance of the NP-decorated SFMC perovskite is observed as the anode for solid oxide fuel cells. Our contribution promotes a fundamental understanding of the interface structure of the exsolved alloy nanoparticles from perovskite substrate.
从钙钛矿中析出催化纳米颗粒（NPs）已成为一种灵活的方法，用于开发具有更高耐久性的高性能功能材料，以应用于能量转换和催化合成领域。在此，我们在原子尺度上揭示了从双钙钛矿基底中析出的合金纳米颗粒的界面结构。结果表明，Co-Fe合金纳米颗粒从SrFeMoCoO（SFMC）双钙钛矿的{100}面终端沿⟨100⟩方向拓扑析出，呈现相同的取向和相同的晶体结构。这两个相的晶格平面在界面处对齐并相互嵌入，形成光滑且连续的共格连接。界面处莫尔条纹的出现证实了拓扑析出机制。共格界面可显著降低界面能，从而使析出的纳米颗粒稳定。因此，作为固体氧化物燃料电池的阳极，观察到NP修饰的SFMC钙钛矿具有优异且稳定的电化学性能。我们的研究有助于从根本上理解从钙钛矿基底中析出的合金纳米颗粒的界面结构。
