Hydriding properties of Zr(Fe xCr 1− x) 2 intermetallic compounds

Abstract

One group of potential hydrogen storage compounds, i.e. Zr(Fe x Cr 1− x ) 2 intermetallics, are investigated. These intermetallics are predominantly single-phased, identified as the hexagonal Laves phase. Hydrogen is absorbed quite readily, with no special activation treatment. Hydrogen absorption results in the formation of a distinct hydride phase, with the same crystal structure as the parent compound. Of these intermetallics, Zr(Fe 0.75Cr 0.25) 2 demonstrates the best overall energy storage characteristics, i.e. a relatively high sorption capacity (H/M = 1) and low hydride stability ( ΔH = −25 kJ mol −1 H 2). This composition compares quite favorably to LaNi 5 in terms of hydrogen capacity, hydride stability and reaction kinetics.