Effect of NiFe-LDH/FeO(OH) derivatives on the hydrogen storage properties of MgH2

Abstract

Magnesium hydride (MgH₂) is hampered in practical applications by inherent thermodynamic and kinetic defects. Herein, the NiFe-LDH/FeO(OH) derivatives have successfully prepared by hydrothermal and calcination and introduced into MgH₂. The results prove that the MgH₂-10 NF-300 composite reveals outstanding hydrogen (H₂) storage performance. The starting dehydrogenation temperature of MgH₂-10 NF-300 is 186.6 °C, and the MgH₂-10 NF-300 desorbs 5.70 wt% H₂ at 300 °C within 5 min. At 150 °C, it has rapidly adsorbed 5.65 wt% H₂ within 1 min. The dehydrogenation activation energy of the composite is 86.71 ± 7.21 kJ/mol, which is reduced by 34.39 % compared to milled MgH₂. Additionally, the capacity retention rates of hydrogen ab/desorption of MgH₂-10 NF-300 after 10 cycles are 97.5 and 98.3 %, respectively, exhibiting good cycling stability. This research has provided sufficient diffusing channels and active sites for H via in-situ generation of Mg₂Ni/Mg₂NiH₄ and Fe, catalyzing together the H₂ storage property of MgH₂. It will provide a new approach to facilitate the practical application of MgH₂.