Xu Nuo, Wang Kaiwen, Zhu Yunfeng, Zhang Yao
School of Materials Science and Engineering, Jiangsu Key Laboratory of Advanced Metallic Materials, Southeast University, Nanjing, 211189, P. R. China.
Beijing Key Laboratory of Microstructure and Property of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing, 100124, China.
Adv Mater. 2023 Sep;35(38):e2303173. doi: 10.1002/adma.202303173. Epub 2023 Jul 28.
Hydrogen storage has long been a priority on the renewable energy research agenda. Due to its high volumetric and gravimetric hydrogen density, MgH is a desirable candidate for solid-state hydrogen storage. However, its practical use is constrained by high thermal stability and sluggish kinetics. Here, PdNi bilayer metallenes are reported as catalysts for hydrogen storage of bulk-MgH near ambient temperature. Unprecedented 422 K beginning dehydrogenation temperature and up to 6.36 wt.% reliable hydrogen storage capacity are achieved. Fast hydrogen desorption is also provided by the system (5.49 wt.% in 1 h, 523 K). The in situ generated PdNi alloy clusters with suitable d-band centers are identified as the main active sites during the de/re-hydrogenation process by aberration-corrected transmission electron microscopy and theoretical simulations, while other active species including Pd/Ni pure phase clusters and Pd/Ni single atoms obtained via metallene ball milling, also enhance the reaction. These findings present fundamental insights into active species identification and rational design of highly efficient hydrogen storage materials.
长期以来，储氢一直是可再生能源研究议程上的一个优先事项。由于其具有较高的体积氢密度和重量氢密度，MgH是固态储氢的理想候选材料。然而，其实际应用受到高热稳定性和缓慢动力学的限制。在此，报道了PdNi双层金属烯作为近环境温度下块状MgH储氢的催化剂。实现了前所未有的422K起始脱氢温度和高达6.36 wt.%的可靠储氢容量。该体系还具有快速的氢解吸能力（在523K下1小时内为5.49 wt.%）。通过像差校正透射电子显微镜和理论模拟，确定原位生成的具有合适d带中心的PdNi合金团簇是脱氢/再氢化过程中的主要活性位点，而通过金属烯球磨获得的其他活性物种，包括Pd/Ni纯相团簇和Pd/Ni单原子，也增强了反应。这些发现为活性物种识别和高效储氢材料的合理设计提供了基本见解。
