The influence of partial substitution of Zr for Ti in TiFe intermetallic compound on the hydrogenation characteristics was investigated. The composition of alloys corresponds to the formula $Ti_{1-x}Zr_xFe$ with x=0,0.01,0.04,0.07,0.1,0.2. X-ray analysis revealed the increase of lattice parameter of alloys with Zr content.
Activation properties were largely enhanced with Zr content and the effect of activation cycles was found to be saturated earlier for Zr-containing compounds than for pure TiFe.
The pressure-composition isotherm were made to see the difference in the thermodynamic properties. The hydrogen storage capacity was drastically decreased and $\gamma$-phase was not appeared. The plateau is inclined and the plateau pressure is lower for Zr-containing compounds than for pure TiFe. The ΔH˚, ΔS˚, ΔG˚ values were obtained from the plot of ln p vs. 1/T by the van't Hoff relation. The hysteresis energy loss was nearly constant with the Zr content.
