Gas atmospheres intrigued microstructure evolution of Ni–Ti based MOFs with exceptional impact on magnesium hydride for hydrogen storage

Magnesium hydride (MgH 2 ) is recognized as a promising candidate for solid-state hydrogen storage due to its high hydrogen capacity and safety. However, its highly stable thermodynamics and slow kinetics pose challenges to its commercial application. To effectively solve these problems, Ni–Ti based MOFs (NT-MOF and NT-MOF- x ( x  = Ar, O 2 , and H 2 )) are prepared as effective catalysts for MgH 2 , with NT-MOF-Ar/MgH 2 showing the best performance. The onset dehydrogenation temperature of NT-MOF-Ar/MgH 2 is reduced to 197 °C and remains 97% H 2 capacity after 20 cycles. An interface reconstruction which enables its superior catalytic performance is evidenced. By in situ forming a multiphase-multivalence Mg-Ni-Ti-C catalytic interface: Mg 2 Ni/Mg 2 NiH 4 act as a hydrogen pump, multivalence Ti facilitates charge transfer, while amorphous carbon mitigates agglomeration, enhancing long-term performance. Our work verifies the interface reconstruction in a MgH 2 hydrogen storage system, thus paving ways for developing new catalytic mechanisms and efficient catalysts for hydrogen storage and other energy related fields. Graphical