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.