Hydrogen Absorption by Mg-Ni-Fe2O3 and Mg-Ni-Ti during Mechanical Grinding under Hydrogen

Abstract

Samples with compositions of 80 wt% Mg-14 wt% Ni-6 wt% Fe2O3 and 80 wt% Mg-14 wt% Ni-6 wt% Ti were prepared by mechanical grinding under hydrogen (reactive mechanical grinding). Their hydrogen absorptions during reactive mechanical grinding were examined. TGA and BET analysis were employed to investigate the hydrogen storage properties of the prepared alloys. TGA analysis of the Mg-14Ni-6Fe2O3 showed an absorbed hydrogen quantity of 6.91 wt% while that of Mg-14Ni-6Ti was 2.59 wt%. BET analysis showed that the specific surface areas of Mg-14Ni-6Fe2O3 and Mg-14Ni-6Ti after reactive mechanical grinding were 264 m2/g and 64 m2/g, respectively. The larger absorbed hydrogen quantity and the larger specific surface area of Mg-14Ni-6Fe2O3 after RMG than those of Mg-14Ni-6Ti after RMG showed that the effects of Fe2O3 addition are much stronger than those of Ti addition during reactive mechanical grinding.