Hydrogen Desorption from the NaNH₂−MgH₂ System

Ball-milled sodium amide and magnesium hydride (NaNH 2:MgH 2 = 1:1 molar ratio) desorbs 3.3 wt % of hydrogen between 70 and 335 °C with three desorption events. X-ray diffraction indicates that the hydrogen desorption is associated with two unidentified magnesium-containing phases. Fourier transform infrared spectroscopy indicates that these two phases correspond to an imide and nitride, respectively. Analysis of the desorption products shows a large excess of NaH and MgH 2 and that optimizing the starting reagents will increase both the kinetics and the amount of hydrogen desorbed from the system below 165 °C.