| 论文标题 |
Theoretical insights on the exsolved behavior of Ru metallic nanoparticles in titanate perovskites |
| 作者 |
Zhongjie Lian, Jiaming Yang, Junkai Wang, Lei Fu, Chu Wang, Bing Xiao, Jun Zhou*, Kai Wu* |
| 发表/完成日期 |
2021-07-12 |
| 期刊名称 |
Applied Surface Science |
| 期卷 |
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| 相关文章 |
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| 论文简介 |
Abstract
Understanding the formation of active nanoparticles at the surface of perovskite oxide supports is significant for improve electrochemical properties and stability for catalytic and energy conversion applications. Surface-modified titanates via exsolution have shown great potential applications in energy conversion and storage devices. However, the detailed mechanism and behavior of exsolution are unclear, especially on the atomic scale. Herein, we used the framework of density-functional theory (DFT) to investigate the exsolved mechanism of Ru nanoparticles on novel SrTiO3-based nonstoichiometric perovskite, Sr0.975Y0.125Ti0.95Ru0.05O3-δ (SYTR). The results depict that the segregation energy of Ru from bulk to surface turns from positive to negative by partially substituting A-site strontium with yttrium. The formation of oxygen vacancy will accelerate the dynamic process of nanoparticles' exsolution. Furthermore, the transition states of Ru adatoms migrating on the SYTR surface are predicted and it is found that Ru nanoparticles nucleate preferentially around the vicinity of yttrium sites. Finally, a Ru's low activation energy migration path could be obtained due to the introduction of A-site deficiency and surface oxygen vacancies simultaneously. The results demonstrated in this work provide significant insights to understand the mechanism of exsolution behavior in titanate perovskites. |
(创新港)
