Reversible Hydrogen Storage at Moderate Pressure-Temperature Conditions of C14 Laves Phase Alloys of the (Ti0.5-xZr0.5-xNb2x)1(Mn0.5Cr0.5)2 System

Abstract

Hydrogen is increasingly recognized as a crucial alternative to fossil fuels. Solid-state storage utilizing metal hydrides offers a high volumetric density for effective hydrogen storage. In this study, a computational thermodynamic approach was employed to design a C14 Laves phase alloys of the (Ti0.5-xZr0.5-xNb2x)1(Mn0.5Cr0.5)2 system for hydrogen storage at moderate pressure-temperature. Two alloys were designed, namely, (Ti0.5Zr0.5)1(Mn0.5Cr0.5)2 and (Ti0.33Zr0.33Nb0.33)1(Mn0.5Cr0.5)2, corresponding to x = 0 and x = 0.1667, respectively. These alloys were synthesized by arc melting, structurally characterized by different techniques, and had their hydrogen storage properties evaluated in terms of absorption kinetic, pressure-composition-isotherm diagrams, absorption/desorption reversibility, and cycling stability. Both alloys presented hydrogen absorption/desorption reversibility under mild pressure and temperature conditions with excellent cycling stability, making them potential candidates for different hydrogen-related technologies.