Enhanced dehydrogenation properties and mechanism analysis of MgH2 solid solution containing Fe nano-catalyst

Magnesium hydride (MgH2) has been proposed as a promising hydrogen storage material due to its high hydrogen capacity. However, its application is hindered by sluggish kinetics and high dehydrogenation temperature. Herein, we report the successful preparation of the Fe containing MgH2 solid solution by milling method, and systematically investigate the dehydrogenation properties and mechanism of the composite through experiments and first principle calculations. The results show that the serious lattice distortion and charge transfer caused by Fe atoms lead to the instability of MgH2, significantly improving the dehydrogenation kinetics of MgH2. As a result, the dehydrogenation activation energy of MgH2-Fe composite was successfully reduced by 44.5%. Notably, the initial dehydrogenation temperature of the composites is nearly 200 degrees C lower than that of pure MgH2, and 4.5 wt% of H2 can be released at 230 degrees C for 30 min. These findings provide novel insights for designing simple, low-cost catalysts for MgH2 synthesis.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This study successfully prepared Fe containing MgH2 solid solution by the milling method, and systematically investigated its dehydrogenation properties and mechanism. The results showed that the lattice distortion and charge transfer caused by Fe atoms significantly improved the dehydrogenation kinetics of MgH2, reducing the dehydrogenation activation energy by 44.5%. The initial dehydrogenation temperature of the composite was nearly 200 degrees C lower than that of pure MgH2, and 4.5 wt% of H2 could be released at 230 degrees C for 30 min.