Magnesium nanopowder for hydrogen absorption and ammonium perchlorate decomposition

Magnesium nanopowder (MgNP) of 17 nm average size was produced by planetary ball milling of Mg (ϕ=229 μm) with 10 wt% NaCl (ϕ=406 μm) for 50 h. NaCl was omissible by dissolution in saturated KOH. Partial oxidation of MgNP occurred, however, in presence of KOH. MgNP–NaCl mixture was, therefore, used for transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), differential scanning calorimetry (DSC) and Sieverts equilibrium investigation. DSC analysis of ammonium perchlorate showed one endothermic and three exothermic reactions. MgNP did not noticeably affect on the initial endothermic reaction. But it decreased transformation temperatures of the second and the third exothermic reactions and increased their heat generation. MgNP 10% NaCl mixture absorbed hydrogen and showed depressing effect on NH4ClO4 decomposition temperature more than initial Mg micropowder.

► Ball milling with NaCl could reduce Mg microparticle size down to 17 nm.
► H2 absorption dramatically increased with Mg size reduction.
► Presence of salt did not impede hydrogen evolution when Mg was hydrolyzed with water.
► Mg nanopowder depressed decomposition temperature of the ammonium perchlorate.