Patent ID: 8216545

Claim:
A method for reversibly desorbing and/or absorbing hydrogen using a doped hydrogen storage material according to the general formula: Mg x B y M z H n wherein: (i) the ratio of x/y is in the range of from 0.48 to 0.70, but outside the range of from 0.49 to 0.51; (ii) z is in the range of from 0.005 to 0.35; (iii) x+y+z equals 1; (iv) M is at least one metal selected from the group consisting of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn; (v) n is no more than 4y; and wherein at least part of the doped hydrogen storage material is amorphous, the method comprising: a) dehydriding the doped hydrogen storage material by desorbing hydrogen from the doped hydrogen storage material to obtain hydrogen gas and a partially dehydrided doped hydrogen storage material, whereby the obtained partially dehydrided doped hydrogen storage material comprises at least 30 atomic % of the maximum amount of atomic hydrogen which can be stored in the doped hydrogen storage material; and b) hydriding the partially dehydrided doped hydrogen storage material by contacting the partially dehydrided doped hydrogen storage material with a hydrogen-comprising gas to reversibly store hydrogen and to obtain an at least partially rehydrided doped hydrogen storage material.