Fuel cells are often seen as a long-term solution to environmental problems such as CO₂ emission associated with transportation. To ensure long-term sustainability and the supply of fuel, new renewable of hydrogen (H₂) generator have to be introduced. In this study, Ni-rich AZ91D magnesium alloy ingot, which was considered as waste material, was used as a H₂ generator in sodium chloride (NaCl) solution with catalyst. The chemical reaction Mg+H₂O→H₂+Mg(OH)₂ occurred in NaCl aqueous solution. The H₂ evolution rate depended on the solution’s temperature (25 or 70°C), length of catalyst (0.9 or 1.8 m) and the concentration of NaCl solution (5 or 10 mass%). The H₂ evolution rate increased with increasing the solution’s temperature. The catalyst (Pt wire) could significantly improve the H₂ generation rate. In addition, the by-product of this method is Mg(OH)₂, a non-toxic chemical compound which is usually used as flame retardant.