First principles study on the improved dehydrogenating properties of MgH2 systems with metal fluorides

Energies and electronic structures of MgH(2) systems were determined from the first principles calculations to explain the improving of their dehydrogenating properties by addition of metal fluorides as catalysts. These calculations show that a Mg vacancy can improve the thermodynamics of MgH(2) systems and Mg atom replaced for Fe, Ti, Zr, V, Ni, Nb, Cr, Cu is energetically more favourable than formation of Mg vacancies at lower temperatures. Calculations of density of states (DOS) provide a particularly good explanation for a close agreement between the experimental results and theoretical predictions for improvements to the dehydrogenation kinetics of MgH(2) systems for NiF(2), NbF(5), ZrF(4) used as the catalysts.