Kinetics of isothermal hydrogenation of magnesium with TiH2 additive

Abstract

Ball-milled magnesium hydride with titanium hydride as a catalytic additive has been demonstrated to have excellent hydrogenation and dehydrogenation kinetics in recent studies, and is considered to be a promising material for hydrogen storage and thermal energy storage applications. The present work investigated the hydrogenation kinetics of this material across a wide temperature range, from room temperature to 200 °C using a Sieverts type apparatus. The kinetics tests were conducted under a methodically designed isothermal condition to minimize the thermal gradient effect, which is often neglected in the literature. It was found that the hydrogenation kinetics under isothermal conditions were significantly different from those under non-isothermal conditions. Additionally, it was determined that the hydrogenation kinetics under isothermal conditions were numerically best fit by the Johnson–Mehl–Arrami model.