Solid-Solution Alloy Nanoparticles of the Immiscible Ir-Cu System with a Wide Composition Range for Enhanced Electrocatalytic Applications
Solid-Solution Alloy Nanoparticles of the Immiscible Ir-Cu System with a Wide Composition Range for Enhanced Electrocatalytic Applications
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具有宽成分范围的不混溶 Ir-Cu 系统固溶体合金纳米粒子，用于增强电催化应用
DOI：
10.1002/ange.201800650
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
H. Kitagawa
中科院分区：
文献类型：
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作者：
F. Wang;K. Kusada;D. Wu;T. Yamamoto;T. Toriyama;S. Matsumura;Y. Nanba;M. Koyama;H. Kitagawa
我们首次合成了尺寸约为100 nm的Ir和Cu的固溶体合金纳米颗粒。2nm，尽管Ir和Cu在整个组成范围内在本体中不混溶直到它们熔化。 我们使用粉末X射线衍射、扫描透射电子显微镜结合能量色散X射线光谱和X射线光电子能谱对IrxCu1− x固溶体合金的性质进行了系统的表征。结果表明，IrxCu1− x合金具有面心立方结构，随着Cu含量的增加，Ir 4f峰向低能区移动，发生了Cu向Ir的电荷转移. 此外，我们观察到，合金化的Ir与Cu增强的电催化析氧和氧还原反应。活性的增强可归因于Ir和Cu之间的电子相互作用，这是由原子水平上的合金化效应引起的。
For the first time, we synthesize solid‐solution alloy nanoparticles of Ir and Cu with a size of ca. 2 nm, despite Ir and Cu being immiscible in the bulk up to their melting over the whole composition range. We performed a systematic characterization on the nature of the IrxCu1−xsolid‐solution alloys using powder X‐ray diffraction, scanning transmission electron microscopy coupled with energy‐dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy. The results showed that the IrxCu1−xalloys had a face‐centered‐cubic structure; charge transfer from Cu to Ir occurred in the alloy nanoparticles, as the core‐level Ir 4f peaks shifted to lower energy region with the increase in Cu content. Furthermore, we observed that the alloying of Ir with Cu enhanced both the electrocatalytic oxygen evolution and oxygen reduction reactions. The enhanced activities could be attributed to the electronic interaction between Ir and Cu arising from the alloying effect at atomic‐level.