Empowering hydrogen storage performance of MgH2 by nanoengineering and nanocatalysis

Abstract With advantages of high hydrogen capacity, excellent reversibility and low cost, magnesium hydride (MgH2) has been considered as one of the most promising candidates for solid state hydrogen storage. However, the practical use of MgH2 as hydrogen storage medium still needs to overcome great barriers both in the thermodynamics and kinetics. In this respect, nanotechnology plays an important role. Employing appropriate nanocatalysts for the hydrogen sorption and/or reducing the particle size of MgH2 to nanoscale have been demonstrated to be effective strategies. In this review, we present a detailed survey on the recent advances in nanocatalysts and nanostructuring for high-performance MgH2. First, we introduce various categories of nanocatalysts, especially including metals and their compounds, focusing on their effects on hydrogen sorption performance of MgH2. Then nanostructuring methods for preparation of small-sized freestanding Mg/MgH2 are discussed, and typical works in nanoconfinement of MgH2 are revisited as a nanostructuring methodology. Finally, we analyze the remaining issues and challenges and propose the prospects of research and development in MgH2 as hydrogen storage materials in the future.