First principles study of dehydrogenation properties of alkali/alkali-earth metal doped Mg₇TiH₁₆

First principles calculations were performed to investigate the influence of vacancy and alkali/alkali earth metals (Li, Na, K and Ca) doping on the dehydrogenation properties of Mg₇TiH₁₆. The occupation energy of dopants and dehydrogenation energy of defected Mg₇TiH₁₆ were calculated. It was found that dopants prefer to substitute for Mg atom leading to a distortion of the structure of the matrix, and therefore destabilize the system. All doped systems were found to possess a lower hydrogen release energy than undoped Mg₇TiH₁₆. The obtained results indicate that alkali/alkali-earth metals represent excellent dopants for Mg₇TiH₁₆ resulting in an improvement of its dehydrogenation characteristics by lowering its equilibrium temperature/pressure.