Song Chulho, Seo Okkyun, Matsumura Daiju, Hiroi Satoshi, Cui Yi-Tao, Kim Jaemyung, Chen Yanna, Tayal Akhil, Kusada Kohei, Kobayashi Hirokazu, Kitagawa Hiroshi, Sakata Osami
Synchrotron X-ray Station at SPring-8, Research Network and Facility Services Division, National Institute for Materials Science 1-1-1 Kouto Sayo Hyogo 679-5148 Japan.
Synchrotron X-ray Group, Research Center for Advanced Measurement and Characterization, National Institute for Materials Science 1-1-1 Kouto Sayo Hyogo 679-5148 Japan
RSC Adv. 2020 May 26;10(34):19751-19758. doi: 10.1039/d0ra03322g.
To unveil the origin of the hydrogen-storage properties of rhodium nanoparticles (Rh NPs), we investigated the dynamical structural change of Rh NPs using dispersive X-ray absorption fine structure spectroscopy (XAFS). The variation of the Rh-Rh interatomic distance and Debye-Waller factor of Rh NPs with a size of 4.0 and 10.5 nm during hydrogen absorption and desorption suggested that they have a different mechanism for hydrogen absorption, which is that the hydrogen absorption on the inner site has a greater contribution than that on a surface for Rh 4.0 nm. In the case of Rh 10.5 nm, it is opposed to Rh 4.0 nm. This study demonstrates a powerful XAFS method for observing small local structural changes of metal nanoparticles and its importance for understanding of the hydrogen-absorption properties of Rh NPs with an interesting hydrogenation mechanism.
为了揭示铑纳米颗粒（Rh NPs）储氢性能的起源，我们使用色散X射线吸收精细结构光谱（XAFS）研究了Rh NPs的动态结构变化。尺寸为4.0和10.5 nm的Rh NPs在吸氢和解吸过程中Rh-Rh原子间距离和德拜-瓦勒因子的变化表明，它们具有不同的吸氢机制，即对于4.0 nm的Rh，内部位点的吸氢贡献比表面更大。在10.5 nm的Rh的情况下，情况与4.0 nm的Rh相反。本研究展示了一种用于观察金属纳米颗粒微小局部结构变化的强大XAFS方法，以及它对于理解具有有趣氢化机制的Rh NPs的吸氢性能的重要性。
