What does this research mean for the field?

KZrH3 exhibits a hydrogen storage capacity of 2.26 wt% at a desorption temperature of 468.765 K, while KHfH3 has a capacity of 1.37 wt% at 381.958 K. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

This research aims to explore the structural, electronic, mechanical, and hydrogen storage properties of KXH3 hydrides with X as Hf and Zr.

February 26, 2026Open Access

Ab initio investigation of the electronic, optical, structural, mechanical, dynamical stability, and hydrogen storage properties of KXH3 (X = Hf and Zr) hydrides

Key Points

This research aims to explore the structural, electronic, mechanical, and hydrogen storage properties of KXH3 hydrides with X as Hf and Zr.
Utilized the CASTEP package for calculations
Assessed structural and mechanical properties using elastic constants
Evaluated dynamic stability through phonon dispersion curves
Measured hydrogen storage capacities and desorption temperatures for KHfH3 and KZrH3
KHfH3 exhibits a hydrogen storage capacity of 1.37 wt% at a desorption temperature of 381.958 K
KZrH3 shows a higher hydrogen storage capacity of 2.26 wt% at 468.765 K
Dynamic and thermodynamic stability confirmed through negative formation enthalpies
Elastic constants indicate mechanical stability and brittle behavior

Abstract

Perovskite-type hydride materials offer potential for storing hydrogen, which is an essential way towards sustainable energy. In this study, the hydrogen storage, structural, mechanical, electronic, dynamic, and optical properties of KXH 3 (X = Hf, Zr) compounds were conducted using the CASTEP package. Phonon dispersion curves and negative formation enthalpies established the dynamic and thermodynamic stability of all of the compounds. In addition, their mechanical stability was affirmed through elastic constants meeting the Born criteria. Property assessments based on Pugh's B/G ratio, Cauchy pressure, and the anisotropic factor indicated their brittle nature, anisotropic behavior, and ionic bonding in these materials. The hydrogen storage capacities were found to be 1.37 wt% for KHfH 3 and 2.26 wt% for KZrH 3 , corresponding to the hydrogen desorption temperatures of 381.958 K and 468.765 K, respectively. Thus, the results highlight the prospects of KXH 3 hydrides in hydrogen storage technology.

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Cite This Study

Azdad et al. (Mon,) studied this question.

synapsesocial.com/papers/699fe24b95ddcd3a253e620e https://doi.org/https://doi.org/10.1016/j.nxmate.2026.101776