Visbal Heidy, Omura Takuya, Nagashima Kohji, Itoh Takanori, Ohwaki Tsukuru, Imai Hideto, Ishigaki Toru, Maeno Ayaka, Suzuki Katsuaki, Kaji Hironori, Hirao Kazuyuki
Department of Materials Chemistry, Graduate School of Engineering, Kyoto University, Katsura A3-120, Nishikyo-ku, Kyoto, 615-8530, Japan.
Device Analysis Department, Nissan Arc, LTD., 1, Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan.
Sci Rep. 2021 Mar 18;11(1):6278. doi: 10.1038/s41598-021-85540-8.
We utilized nanoporous mayenite (12CaO·7AlO), a cost-effective material, in the hydride state (H) to explore the possibility of its use for hydrogen storage and transportation. Hydrogen desorption occurs by a simple reaction of mayenite with water, and the nanocage structure transforms into a calcium aluminate hydrate. This reaction enables easy desorption of H ions trapped in the structure, which could allow the use of this material in future portable applications. Additionally, this material is 100% recyclable because the cage structure can be recovered by heat treatment after hydrogen desorption. The presence of hydrogen molecules as H ions was confirmed by H-NMR, gas chromatography, and neutron diffraction analyses. We confirmed the hydrogen state stability inside the mayenite cage by the first-principles calculations to understand the adsorption mechanism and storage capacity and to provide a key for the use of mayenite as a portable hydrogen storage material. Further, we succeeded in introducing H directly from OH by a simple process compared with previous studies that used long treatment durations and required careful control of humidity and oxygen gas to form O species before the introduction of H.
我们使用了纳米多孔钙铝石（12CaO·7Al₂O₃），一种具有成本效益的材料，处于氢化物状态（H），以探索其用于储氢和输氢的可能性。钙铝石与水发生简单反应即可实现氢解吸，其纳米笼结构会转变为水合铝酸钙。该反应能够使被困在结构中的氢离子轻松解吸，这使得这种材料未来有可能用于便携式应用。此外，这种材料可100%回收利用，因为在氢解吸后通过热处理可以恢复笼状结构。通过氢核磁共振、气相色谱和中子衍射分析证实了作为氢离子的氢分子的存在。我们通过第一性原理计算确认了钙铝石笼内氢状态的稳定性，以了解吸附机理和储存容量，并为将钙铝石用作便携式储氢材料提供关键依据。此外，与之前的研究相比，我们通过一个简单的过程成功地直接从羟基引入了氢，之前的研究需要长时间处理，并且在引入氢之前需要仔细控制湿度和氧气以形成氧物种。
