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

A novel preparation process has been developed to synthesize MgH2nanoparticles by combining ball milling and thermal hydrogenolysis of di-n-butylmagnesium (C4H9)2Mg, denoted as MgBu2). With the aid of mechanical impact and the dispersant, the hydrogenolysis temperature of MgBu2in heptane solution was considerably lowered down to 100 oC, and the MgH2nanoparticles with an average particle size ofca.8.9 nm were obtained without scaffolds. The nano-size effect of the MgH2nanoparticles causes a significant decrease in the onset dehydrogenation temperature of 225 oC and enthalpy of 69.78 kJ/mol∙H2. This thermally-assisted milling and hydrogenolysis process may also be extended for synthesizing other nanoscale hydrides and catalysts.