11:15 AM - MT06.19.07
Active and Stable Low-Platinum Catalysts—From In Situ Understanding to Rational Design
Yanling Ma1,Jianbo Wu1
Shanghai Jiao Tong University1
Show Abstract
The core-shell catalysts with atomic layered surface Pt through liquid phase atomic layer deposition has been proven to be one of the most promising oxygen reduction (ORR) electrocatalysts with high activity and low consume of Pt.1-5 It is important to directly observe how the atomic layers grow via in situ technique. On the other hand, corrosion is a major and unavoidable challenge for the degradation of properties of multimetallic core-shell electrocatalysts during electrocatalysis, which restricts the practical application of this type electrocatalysts severely.6-7 Therefore, it has been an urgent issue to understand the evolution and mechanism of corrosion of Pt-based core-shell catalysts during the reaction with an aim to the effective utilization of the catalysts. 8
In this presentation, we will first report a 3D growth mechanism for the formation of core−shell nanostructures involving a hybrid process with initial island growth and surface diffusion. The desired surface structure can be achieved by adjusting the competition between island deposition and surface diffusion.9 Then, we will show the corrosion behavior of Pd@Pt core-shell electrocatalysts in the etching solution, which depends on the effects of geometry and surface defect.10-11 Finally, we can demonstrate the capability of electrochemistry inside of TEM, showing both the oxidative etching and the re-deposition behaviors during the cyclic voltammetry in TEM.
References:
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6. Lim, B.; Jiang, M.; Camargo, P. H.; Cho, E. C.; Tao, J.; Lu, X.; Zhu, Y.; Xia, Y., Science 2009, 324, 1302-1305.
7. Zhang, L.; Roling, L. T.; Wang, X.; Vara, M.; Chi, M.; Liu, J.; Choi, S.-I.; Park, J.; Herron, J. A.; Xie, Y., Science 2015, 349, 412-416.
8. Wu, J.; Shao, H.; Chen, W; Gu, X.; Tao, P.; Song, C.; Shang, W.; Deng, T, Adv. Mater., 2016, 28, 9686-9712.
9. Wu, J.; Gao, W.; Wen, J.; Miller, D. J.; Lu, P.; Zuo, J. M.; Yang, H., Nano Lett., 2015, 15, 2711–2715.
10. Wu, J.; Gao, W.; Yang, H.; Zuo, J. M., ACS Nano, 2017, 11, 1696-1703.
11. Shan, H.; Gao, W.; Xiong, Y.; Shi, F.; Yan, Y.; Ma, Y.; Shang, W.; Tao, P.; Song, C.; Deng, T.; Zhang, H.; Yang, D. R.; Pan, X. P.; Wu, J., Nat. Commun., 2018, 9, 1011