Enhanced activity for oxygen reduction reaction on "Pt3CO" nanoparticles:: Direct evidence of percolated and sandwich-segregation structures
Enhanced activity for oxygen reduction reaction on "Pt3CO" nanoparticles:: Direct evidence of percolated and sandwich-segregation structures
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DOI：
10.1021/ja802513y
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发表时间：
2008-10-22
影响因子：
15
通讯作者：
Shao-Horn, Yang
中科院分区：
文献类型：
--
作者：
Chen, Shuo;Ferreira, Paulo J.;Shao-Horn, Yang
通过像差校正的高角暗场成像获得了铂合金纳米颗粒的原子分辨结构和组成，该成像与基于铂比表面积的比ORR活性相关联。酸处理的Pt3Co纳米粒子比ORR活性的提高(相对于铂的2倍)可能与原子尺度和原子尺度上的组成变化以及单个粒子内渗入的富铂和贫铂区域的形成有关。在退火后，我们发现了表面铂夹心偏析结构的直接证据，其对应的比ORR活性类似于铂的4倍。
Atomically resolved structures and composition of Pt alloy nanoparticles were obtained using aberration-corrected high-angle dark field imaging, which was correlated to specific ORR activity based on a Pt surface area. The enhanced specific ORR activity (similar to 2 times relative to Pt) of acid-treated "Pt3Co" nanoparticles can be related to composition variations at the atomic scale and the atomic scale and the formation of percolated Pt-rich and Pt-poor regions within individual particles. Upon annealing, we show direct evidence of surface Pt sandwich-segregation structures, which correspond to a specific ORR activity similar to 4 times relative to Pt.