Core-Shell Compositional Fine Structures of Dealloyed PtxNi1-x Nanoparticles and Their Impact on Oxygen Reduction Catalysis
Core-Shell Compositional Fine Structures of Dealloyed PtxNi1-x Nanoparticles and Their Impact on Oxygen Reduction Catalysis
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DOI：
10.1021/nl302995z
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发表时间：
2012-10-01
期刊：
影响因子：
10.8
通讯作者：
Strasser, Peter
中科院分区：
文献类型：
--
作者：
Gan, Lin;Heggen, Marc;Strasser, Peter
利用像差校正的扫描电子显微镜和Angstrom分辨率的电子能量损失谱线，我们发现了一系列催化活性的非合金化PtxNi1-x核壳纳米粒子中新颖的核-壳精细结构，显示出异常的近表面富镍内壳的形成。富镍内壳的径向位置和成分敏感地依赖于初始合金成分。我们进一步讨论了这些自组织富镍内层如何在维持表面晶格应变从而控制表面氧还原催化活性方面起到关键作用。
Using aberration-corrected scanning transmission electron microscopy and electron energy loss spectroscopy line profiles with Angstrom resolution, we uncover novel core-shell fine structures in a series of catalytically active dealloyed PtxNi1-x core-shell nanoparticles, showing the formation of unusual near-surface Ni-enriched inner shells. The radial location and the composition of the Ni-enriched inner shells were sensitively dependent on the initial alloy compositions. We further discuss how these self-organized Ni-enriched inner shells play a key role in maintaining surface lattice strain and thus control the surface catalytic activity for oxygen reduction.