Superior hydrogen storage kinetics of MgH2 by in-situ generated α-Fe from the Fe-zeolitic imidazolate framework

While MgH2 is one of the promising hydrogen storage materials, its poor de/hydrogenation kinetics have hindered its potential applications. Here, we report that kinetic and cycle properties can be improved using Fe-doped zeolitic imidazolate framework (Fe-ZIF) as the catalysts. The synthesized MgH2@5 wt.% Fe-ZIF can absorb 5.0 wt.% hydrogen in 1 min at 200 °C and desorb 5.0 wt.% hydrogen within 16 min at 300 °C. No clear degradation of catalytic effects was observed over 30 cycles. Structural analysis revealed that the Fe-ZIF gradually decomposed into α-Fe, which strongly interacts with MgH2, realizing much higher catalytic activity and stability. Furthermore, the Fe-ZIF is characterized by a simple process and low cost nature, posing the metal-ZIF composite as a promising platform to disperse nano-catalysts in Mg-based hydrogen storage materials.