for the disintegration or complete removal of the Mg(OH)2 passive layer during hydrolysis of MgH2 . The acids should satisfy to the following requirements: (i) their magnesium salts should be soluble in water, (ii) the acidic solution should not cause corrosion of hydrogen generation apparatus, (iii) the vapours of acids should not be released together with the generated hydrogen, (iv) the acids and their magnesium salts should be non-toxic and environment friendly.