Constructing a Favorable Microenvironment for Robust Hydrogen Storage in MgH2 Through Synergistic Cooperation With Mn and Mg2Ni

en Weakening the electrostatic attraction between Mg 2+ ions and H − ions in MgH 2 is vital for improving the kinetic performance of MgH 2 for hydrogen storage. Herein, a multivalent microenvironment is synergistically created by Mn and Mg 2 Ni to break the stable structure of MgH 2 , enabling rapid and stable de/hydrogenation performance. Specifically, the catalyzed MgH 2 system rapidly emits 5.98 wt% H 2 at 265°C within just 20 min and swiftly absorbs 6.24 wt% H 2 at 150°C in a mere 10 min. Microscopic characterization shows that a tight interface is formed between Ni and Mn 2 O 3 , which provides a stable anchor point for the formation of hydrogen pumps. Additionally, the multivalency of Mn and abundant oxygen vacancies accelerate the electron transfer and provide the shortest path for H dissociation. Moreover, density functional theory (DFT) indicates that Mg-H is extracted from 0.173 to 0.204 nm after modification, achieving a reduced decomposition energy of MgH 2 . Besides, 97.8% reversible hydrogen storage capacity was maintained after 30 cycles, presenting prominent potential for practical applications. 摘要 zh 削弱MgH 2 中Mg 2+ 离子与H − 离子之间的静电吸引力对于提升MgH 2 作为氢储存材料的动力学性能至关重要。在此,通过Mn与Mg 2 Ni的协同作用,构建了多价微环境,打破了MgH 2 的稳定结构,从而实现了快速且稳定的脱氢和加氢性能。具体而言,催化后的MgH 2 体系在265°C下仅需20分钟即可快速释放5.98 wt%的H 2 ,并在150°C下仅需10分钟即可迅速吸收6.24 wt%的H 2 。微观表征显示,Ni与Mn 2 O 3 之间形成紧密界面,为氢泵的形成提供了稳定的锚定点。并且,锰的多价性和丰富的氧空位加速了电子转移,并为氢的解离提供了最短路径。此外,DFT表明,经过改性后,Mg-H键键长从0.173 nm增加至0.204 nm,从而降低了MgH 2 的结合能。此外,经过30个循环后,可逆氢储存容量仍保持在97.8%,展现出显著的实际应用潜力。