Non-stoichiometric AB2 alloys with (Ti0.75Zr0.25)1.05Mn0.8CrTM0.2 (TM = Cr, Mo, and Nb) formulation were synthesized using an arc-melting method in an argon atmosphere to optimize storage, activation, and kinetic reaction properties of hydrogen. The structural, morphological, and hydrogen storage properties of the alloys were examined using X-ray difraction, feld-emission scanning electron microscopy, energy-dispersive X-ray mapping, and volumetric method, respectively. The results indicate that the Mo sample exhibits the highest hydrogen storage capacity at 1.34 wt%. This result is due to the solid solution phase (TiMo), which acts as a catalyst and facilitates hydrogen absorption. The best value of the plateau slope for the Nb sample at room temperature was 0.65, and the hysteresis coefcient was 0.239 for the Mo sample. In addition, the dissociation enthalpy (∆HDES) and entropy (∆SDES) for the Nb sample were 31.04 kJ ­mol−1 and 103.93 J ­mol−1 ­K−1, respectively. From the analysis of the hydrogen absorption kinetic curves, it was found that the reaction kinetic behavior is consistent with the Jander model. Furthermore, activation energy values of the alloys were calculated at a pressure of 13 bar and the range of temperature from 298 to 328 K. We obtained Ea(Cr) = 14.02, Ea(Mo) = 10.92, and Ea(Nb) = 10.23 kJ ­mol−1. Based on the results, the Nb sample showed good absorption/desorption plateau pressure properties with small hysteresis and slope.

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