Influence of chloride salts on hydrogen generation via hydrolysis of MgH2 prepared by hydriding combustion synthesis and mechanical milling

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.