Pressure–composition isotherm behavior of an Mg–YSZ composite synthesized by hydrogen-induced mechanical alloying

Abstract

The most attractive way to store hydrogen safely and economically is by storing it in metal hydrides. In particular, magnesium has attracted much interest since its hydrogen storage capacity exceeds that of known metal hydrides. Mg and Mg-based materials are lightweight and low cost, with high hydrogen storage capacity (7.6 wt%). However, commercial applications of Mg hydrides are currently hindered by their high absorption/desorption temperature and very slow reaction kinetics. One of the ways to improve the kinetics is by the addition of transition metal oxide. In this study, we have tried to improve the hydrogen absorption properties of Mg. The effect of transition oxides, such as YSZ (Y2O3-stabilized ZrO2), on the kinetics of the Mg hydrogen absorption reaction was investigated. MgHx–YSZ composites were synthesized by hydrogen-induced mechanical alloying. The powder synthesized was characterized by XRD, SEM, EDS and simultaneous TG/DSC analysis. The hydrogenation behaviors were evaluated using a Sievert's type automatic PCT apparatus. The absorption kinetics of MgHx with 5 wt% YSZ composites were determined at 423, 473, 523, 573 and 623 K.