Abstract:The effects of chloride salts (NaCl, MgCl₂ and NH₄Cl) on the hydrolysis kinetics of MgH₂ prepared by hydriding combustion synthesis and mechanical milling (HCS+MM) were discussed. X-ray diffraction (XRD) analyses show that high-purity MgH₂ was successfully prepared by HCS. Hydrolysis performance test results indicate that the chloride salt added during the milling process is favorable to the initial reaction rate and hydrogen generation yield within 60 min. A MgH₂-10% NH₄Cl composite exhibits the best performance with the hydrogen generation yield of 1311 mL/g and a conversion rate of 85.69% in 60 min at room temperature. It is suggested that the chloride salts not only play as grinding aids in the milling process, but also create fresh surface of reactive materials, favoring the hydrolysis reaction.

Key words: MgH₂; hydrogen generation yield; hydrolysis reaction; chloride salts; hydriding combustion synthesis; mechanical milling