Perovskite hydrides XBeH 3 (X = Al, Ga, In) for solid-state hydrogen storage applications: First-principles insights into storage capacity, desorption temperature, mechanical, vibrational, and optoelectronic characteristics

The creation of advanced, sustainable, and green energy technologies significantly relies on the scrutiny of effective hydrogen (H 2 ) storage substances. Perovskite hydrides with tunable structure, stability, and multifunctional characteristics are emerging candidates being reported for hydrogen technologies for storage in solid-state form. In the present exploration, density functional theory (DFT) is used to evaluate the structural, hydrogen-storage, electronic, mechanical, thermodynamic, and optical attributes of XBeH 3 (X = Al, Ga, In). The examined variants of hydride materials are all observed to be in a stable cubic lattice, crystallizing in the Pm-3m space group (No. 221). The comprehensive scrutiny of hydrogen storage traits is conducted for the analysis of the potential of hydrides. The storage capacities (SC) of AlBeH 3 , GaBeH 3 , and InBeH 3 hydrides are 7.75 wt%, 3.70 wt%, and 2.38 wt%, respectively. The desorption temperature for the release of H 2 is reported to be 347 K, 303 K, and 251 K, for AlBeH 3 , GaBeH 3 , and InBeH 3 , respectively, which is compatible with the optimal effective desorption range (233-358 K). Among these hydrides, AlBeH 3 has the best hydrogen-storage performance (7.75 wt% and 347 K) of the three compositions, suggesting it is promising as an efficient substance for storage technologies. The mechanical analysis of elastic coefficients, elastic moduli, ratios (Pugh and Poisson), and anisotropic parameters demonstrates that XBeH 3 hydrides exhibit brittleness with mechanical stability and anisotropy. The electronic parameters and optical aspects reveal that AlBeH 3 , GaBeH 3 , and InBeH 3 metallic hydrides, paving the way for easier hydrogen desorption. Ab initio molecular dynamics (AIMD) simulation shows variation of total energy versus simulation time, which suggests minimal total energy variation and confirms thermodynamic stability. The predicted metrics, such as stability, H 2 storage capacities, and desorption aspects, recommend experimental validation and highlight the compatibility of hydrides for advanced solid-state hydrogen storage (HS) systems.