Le Thi Thu, Bordignon Simone, Chierotti Michele R, Shang Yuanyuan, Schökel Alexander, Klassen Thomas, Pistidda Claudio
Institute of Hydrogen Technology, Helmholtz-Zentrum hereon GmbH, Max-Planck-Straße 1, Geesthacht D-21502, Germany.
Department of Chemistry, University of Torino, V. P. Giuria 7, Torino I-10125, Italy.
Inorg Chem. 2024 Jun 17;63(24):11233-11241. doi: 10.1021/acs.inorgchem.4c01016. Epub 2024 May 30.
Mixed solid solutions have played an important role in improving the kinetics and performance of hydrogen storage materials, as reported for the Li-Mg-N-H, K-Mg-N-H, and Rb-Mg-N-H systems. Besides, the formation of a homogeneous solid solution, mostly due to partial ionic substitution, is known to be an effective approach to improve the ionic conductivity of a material, which is an important property in electrochemical applications. We have reported a series of solid solutions based on mixed amide-hydride materials of the Group 1 elements, e.g., K(NH)H, Rb(NH)H, and Cs(NH)H, via the exchange of NH/H anions with the change of the lattice cell of the solid solution. Extending the research in this direction, we study the M-N-H solid solution in the MNH-MH systems (M = K, Rb, Cs, and their combinations), i.e., KNH-RbH, RbNH-KH, RbNH-CsH, and CsNH-RbH via ex situ/in situ XRD, IR, and H 2D solid-state NMR. The results obtained confirm the formation of mixed metal amide-hydride solid solutions associated with an exchange between both anionic (NH and H) and cationic species (K, Rb, and Cs). With this study, we aim to create an accessible library of M-N-H solid solutions for further studies as additives for hydrogen storage materials or ionic conductors.
如关于Li-Mg-N-H、K-Mg-N-H和Rb-Mg-N-H体系的报道所示，混合固溶体在改善储氢材料的动力学和性能方面发挥了重要作用。此外，形成均匀固溶体（主要由于部分离子取代）是提高材料离子电导率的有效方法，而离子电导率是电化学应用中的一个重要性质。我们通过NH/H阴离子交换以及固溶体晶格单元的变化，报道了一系列基于第1族元素混合酰胺-氢化物材料的固溶体，例如K(NH)H、Rb(NH)H和Cs(NH)H。在此方向上拓展研究，我们通过非原位/原位XRD、IR和二维固态核磁共振研究了MNH-MH体系（M = K、Rb、Cs及其组合）中的M-N-H固溶体，即KNH-RbH、RbNH-KH、RbNH-CsH和CsNH-RbH。所得结果证实了混合金属酰胺-氢化物固溶体的形成，这与阴离子（NH和H）和阳离子物种（K、Rb和Cs）之间的交换有关。通过这项研究，我们旨在创建一个便于获取的M-N-H固溶体库，用于进一步研究作为储氢材料或离子导体的添加剂。
