A DFT study on how vanadium affects hydrogen storage kinetics in magnesium nickel hydride

Abstract

Magnesium nickel hydride (MNH), Mg2NiH4 is a promising material that was shown enhance the hydrogen storage performance. Also, further modification of such a material included the incorporation of V into the host under hydrogen pressure to form the VH/Mg2NiH4 catalyst. However, investigations on its catalytic performance are still in need. Thus, this work studied via density functional theory, the improved hydrogen storage kinetics on VH/Mg2NiH4(101). The molecular hydrogen desorption was found to improve on such a system. The hydrogen vacancy sites (HV) formed at the interfacial sites. Consequently, all H and HV diffusion pathway and TOF derived from the most favorable diffusion pathway was investigated to understand the desorption and diffusion processes at the active site. Hence, this DFT investigation can be used to guide the design of high-performance Mg-based hydrogen storage materials.