Nanoporous Mg Structure through Organic Solvent-based Reductive Method for Solid-State Hydrogen Storage

Abstract

Solid-state hydrogen storage with higher volumetric energy density than liquid or gaseous hydrogen storage can be the solution for effective hydrogen energy utilization. Especially, Mg is a strong candidate with high hydrogen capacity of 7.6 wt.% and abundance on Earth, but it still needs further improvements because of its sluggish kinetics and high desorption temperature. In this study, Mg with porous structure is synthesized using reduction-induced decomposition. Porous structure may improve the kinetics with reduced hydrogen diffusion length and high surface area and alleviate the volume expansion in the hydrogen storage process. The synthesis method used in this study is a facile and scalable solution-based method, which is more efficient than the conventional dealloying method to synthesize porous metal. The obtained product shows well-crystallized pure Mg porous structure and its hydrogen uptake/release capacity increases up to about 6 wt.% as hydrogen cycle proceeds. Hydrogen storage through porous Mg structures could be a potential application in the future, which will advance the hydrogen energy industry.