First-Principles Computational Screening of Perovskite Hydrides for Hydrogen Release

This study investigates perovskite hydrides (ABH₃) comprising alkali metals of A, where A is Li, Na, K, Rb, or Cs, and alkaline-earth metals of B, where B is Be, Mg, Ca, Sr, or Ba, to screen the highest potential hydrides for hydrogen release. Herein, we investigated the most favorable dehydrogenation pathway for each ABH₃ system and found that NaCaH₃ was the most attractive ABH₃ system. Analysis was performed to determine the influence of the alkali dopants (at the A-site) and alkaline-earth dopants (at the B-site) on hydrogen release from NaCaH₃. For this analysis, we calculated the reaction enthalpies of a NaCaH₃ system for hydrogen release with different dopants and pathways. Cs was the best dopant for improving hydrogen release with the lowest reaction enthalpy. However, no clear effect from B-site doping on the dehydrogenation was found.