Bimetallic alloy nanoparticles (NPs) exhibit superior catalytic and chemical storage properties relative to the monometallic NPs. Previously, it has been reported that bimetallic AgRh forms solid-solution alloy NPs that have unusual hydrogen storage properties not commonly observed in individual Ag and Rh NPs. Here, we use a combination of X-ray diffraction (XRD) and X-ray absorption fine structure spectroscopy (XAFS) techniques to investigate the microstructure and unique hydrogen absorption properties of bulk immiscible AgRh alloy NPs. XRD analysis reveals that the long-range structure of the alloy sample can be estimated as a single fcc phase with a slightly smaller lattice parameter than that of the bulk Ag and larger than that of bulk Rh. XAFS analysis reveals that charge transfer between Rh and Ag occurs in this interfacial region. The near-edge profile reveals a variety of local environments for Ag and Rh, including distinct atomic pair distances and disorder. The atomic pair distances were compressed around Ag and elongated around Rh. A substantial fraction of the sample is an alloy phase formed by mixing of nano/sub-nanosized domains of Rh and Ag NPs. Mixing at the atomic level mainly occurs in the interfacial region. Consequently, the interfacial region has an important influence over the microstructure and provides active sites for hydrogen absorption.

相对于单金属NP，双金属合金纳米颗粒（NP）表现出优异的催化和化学存储性能。以前，已经报道了双金属AgRh形成固溶合金NP，其具有不寻常的储氢特性，这在单个Ag和Rh NP中通常不观察到。在这里，我们结合使用X射线衍射（XRD）和X射线吸收精细结构光谱（XAFS）技术来研究块状不混溶AgRh合金NP的微观结构和独特的氢吸收性能。XRD分析表明，合金样品的长程结构可以估计为单一的fcc相，其晶格参数比块状Ag的晶格参数略小，但比块状Rh的晶格参数大。XAFS分析表明，Rh和Ag之间的电荷转移发生在该界面区域。近边缘轮廓揭示了Ag和Rh的各种局部环境，包括不同的原子对距离和无序。原子对距离在Ag周围被压缩，在Rh周围被拉长。样品的很大一部分是通过混合Rh和Ag NP的纳米/亚纳米域形成的合金相。原子级的混合主要发生在界面区域。因此，界面区域对微结构具有重要影响，并为氢吸收提供了活性位点。原子级的混合主要发生在界面区域。因此，界面区域对微结构具有重要影响，并为氢吸收提供了活性位点。原子级的混合主要发生在界面区域。因此，界面区域对微结构具有重要影响，并为氢吸收提供了活性位点。