(¹ State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082)
(² School of Vehicle and Mechanical Engineering, Changsha University of Science & Technology, Changsha 410114)
(³ School of Materials Science and Engineering, Hunan University, Changsha 410082)

A NbH_0.6/MgH₂ interface is designed and constituted in this work. A first-principles plane-wave pseudopotentials method based on Density Functional Theory (DFT) has been used to investigate the Niobium alloying effects on the dehydrogenating properties and electronic structure of magnesium hydride, i.e., MgH₂. A low absolute value of the negative heat of formation of NbH_0.6/MgH₂ interface compared with that of MgH₂ indicates Niobium hydrides befit to improve the dehydrogenating properties of MgH₂. Based on the analysis of the density of states (DOS) and the total electron density distribution of MgH₂ before and after Nb alloying, it was found that the catalysis effect of Nb on dehydrogenating kinetics of MgH₂ may attribute to a stronger bonding between Nb and H atoms than that between Mg and H atoms, which leads to nucleation of NbH_0.6 phase and the α-Mg at the NbH_0.6/MgH₂ interface in the MgH₂-Nb systems is easier than in pure MgH₂ phase.