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Dehydrogenation Mechanism In Catalyst-Activated Mgh2, S. Li, Puru Jena, R. Ahuja

Physics Publications

A small amount of Nb2O5 catalyst is known to substantially improve the desorption thermodynamics and kinetics of MgH2. Using density functional theory in combination with ab initio molecular dynamics simulation, we provide theoretical understanding of the mechanism of dehydrogenation in Nb doped MgH2. We show that the substitution of Nb at the Mg site followed by the clustering of H around Nb is a likely pathway for hydrogen desorption. We also find that dehydrogenation from the vicinity of Mg vacancies is exothermic. However, the vacancies are not likely to play a significant role in hydrogen desorption due to their high …