Thermally-assisted milling and hydrogenolysis for synthesizing ultrafine MgH2 with destabilized thermodynamics

Abstract A novel process has been developed to synthesize MgH 2 nanoparticles by combining ball milling and thermal hydrogenolysis of di- n -butylmagnesium (C 4 H 9 ) 2 Mg, denoted as MgBu 2 . With the aid of mechanical impact, the hydrogenolysis temperature of MgBu 2 in heptane and cyclohexane solution was considerably lowered down to 100 °C, and the MgH 2 nanoparticles with an average particle size of ca. 8.9 nm were obtained without scaffolds. The nano-size effect of the MgH 2 nanoparticles causes a notable decrease in the onset dehydrogenation temperature of 225 °C and enthalpy of 69.78 kJ mol −1 · H 2 . This thermally-assisted milling and hydrogenolysis process may also be extended for synthesizing other nanomaterials.