Elastic Framework Driven Mg2+ Autocapture and Autocatalysis: Mechanistic Origin of Fast Hydrogen Release in 2LiBH4–MgH2

en This link goes to a English section zh This link goes to a Chinese section The protracted incubation time has long been the Achilles' heel of the promising 2LiBH 4 –MgH 2 hydrogen storage system. Instead of the usual route-creating heterogeneous nucleation sites to hasten MgB 2 formation, we shortened both de- and re-hydrogenation incubation periods by steering the Mg transformation itself. Herein, this paper engineered a Prussian blue analog whose surface charge landscape traps Mg 2+ and the released electrons in a non-stoichiometric lattice, keeping them instantly available for MgB 2 nucleation. Theory and experiment show that CoFe–PBA stores both ions and electrons. Under the same experimental temperature, the optimized LiBH 4 –MgH 2 hydrogen storage system demonstrates remarkable performance improvements: Its incubation period is significantly reduced to just one seventh that of the original hydrogen storage material, achieving a leap forward in reaction kinetics efficiency. The above concept provides a versatile tool for any catalytic system constrained by nucleation delays and opens new avenues for energy-related research. 摘要 en This link goes to a English section zh This link goes to a Chinese section 2LiBH 4 –MgH 2 高容量储氢体系的实际应用长期受限于漫长的MgB 2 成核孕育期。本研究另辟蹊径,通过储镁效应对镁自身转化过程进行调控而非采用传统的制造异质成核位点来加速MgB 2 的生成,从而成功缩短了该体系吸放氢过程的孕育期。首先设计合成了一种普鲁士蓝类似物(CoFe–PBAs),其表面电荷分布特性可将Mg 2+ 及其释放的电子捕获于非化学计量晶格中,使其随时可用于MgB 2 的成核。理论与实验共同证实,CoFe–PBAs能同时储存镁离子与电子;在相同实验温度下,优化后的LiBH 4 –MgH 2 储氢体系展现出显著的性能提升:其孕育期大幅缩短至未改性体系的七分之一,实现了无催化体系反应动力学效率的飞跃。上述概念开辟了能源催化领域相关研究的新调控途径,为任何受成核延迟限制的催化体系提供了一种普适性的解决方案。