Abstract
Based on experimental results in which VH0.81/MgH2 interface was found during the process of mechanically milling MgH2+5at%V nanocomposite, a VH/MgH2 interface is designed and constituted in this work. A first-principles plane-wave pseudopotential method based on Density Functional Theory (DFT) has been used to investigate the vanadium alloying effects on the dehydrogenating properties of magnesium hydride, i.e., MgH2. A low absolute value of the negative heat of formation of VH/MgH2 interface compared with that of MgH2 indicates that vanadium hydrides befit to improve the dehydrogenating properties of MgH2. Based on the analysis of the density of states (DOS) and the total valence electron density distribution of MgH2 before and after V alloying, it was found that the improvement of the dehydrogenating properties of MgH2 caused by V alloying originates from the increasing of the valence electrons at Fermi level (E F) and the decreasing of the HOMO-LUMO gap (ΔE H-L) after V alloying. The catalysis effect of V on dehydrogenating kinetics of MgH2 may attribute to a stronger bonding between V and H atoms than that between Mg and H atoms, which leads to nucleation of the α-Mg at the VH/MgH2 interface in the MgH2-V systems easier than that in pure MgH2 phase.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Liang, G., Huot, J., Boily, S. et al., Hydrogen desorption kinetics of a mechanically milled MgH2+5at.%V nanocomposite, J. Alloys Compd, 2000, 305: 239–245.
Shang, C. X., Bououdina, M., Song, Y. et al., Mechanical alloying and electronic simulations of (MgH2+M) systems (M=Al,Ti,Fe,Ni,Cu and Nb) for hydrogen storage, J. Hydrogenenergy, 2004, 29: 73–80.
Liang, G., Huot, J., Boily, S. et al., Catalytic effect of transition metals on hydrogen sorption in nanocrystalline ball milled MgH2-Tm (Tm=Ti,V,Mn,Fe and Ni) systems, J. Alloys Compd, 1999, 292: 247–252.
Song, Y., Guo, Z. X., Yang, R., Influence of selected alloying elements on the stability of magnesium dihydride for hydrogen storage applications: A first-principles investigation, Phys. Rev. B, 2004, 69: 094205–094215.
Bortz, M., Bertheville, B., Bottqer, G. et al., Structure of the high pressure phase γ-MgH2 by neutron powder diffraction, J. Alloys Compd, 1999, 287: L4–6.
Smithson, H., Marianetti, C. A., Morgan, D. et al., First-principles study of the stability and electronic structure of metal hydrides, Phys. Rev. B, 2002, 66: 144107–144117.
Segall, M. D., Lindan, P. L. D., Probert, M. J. et al., First-principles simulation: ideas, illustrations and the CASTEP code, J. Phys:Condens Matter, 2002, 14: 2717–2743.
Marlo, M., Milman, V., Density-functional study of bulk and surface properties of titanium nitride using different exchange-correlation functionals, Phys. Rev. B, 2000, 62: 2899–2907.
Vanderbilt, D., Soft self-consistent pseudopotentitals in a generalized eigenvalue formalism, Phys. Rev. B, 1990, 41: 7892–7895.
Franscis, G. P., Payne, M. C., Finite basis set corrections to total energy pseudopotential calcaulations, J. Phys: Condens Matter, 1990, 2: 4395–4404.
Hammer, B., Hansen, L. B., Norkov, J. K., Improved adsorption energetics withen density-functional theory using revised Perdew-Burke-Ernzerhof functionals, Phys. Rev. B, 1999, 59: 7413–7421.
Monkhorst, H. J., Pack, J. D., Special points for Brillouin-zone integrations, Phys. Rev. B, 1976, 13: 5188–5192.
Nakamura, H., Nguyen-Manh, D., Pettifor, D. G., Electronic structure and energetics of LaNi5, α-La2Ni10H and β-La2Ni10H14, J. Alloys Compd, 1998, 281: 81–91.
Nambu, T., Ezaki, H., Yukawa, H. et al., Electronic structure and hydriding property of titanium compounds with CsCl-type structure, J. Alloys Compd, 1999, 293–295: 213–216.
Bogdanovíć, B., Bohmhammel, K., Christ, B. et al., Thermodynamic investigation of the magnesium-hydrogen system, J. Alloys Compd, 1999, 282: 84–92.
Imai, Y., Mukaida, M., Tsunoda, T., Comparison of density of states of transition metal disilicides and their related compounds systematically calculated by a first-principle pseudopotential method using plane-wave basis, Intermetallics, 2000, 8: 381–390.
Wang, J., Wang, G., Zhao, J., Density-functional study of Aun(n=2–20) clusters: lowest-energy structures and electronic properties, Phys. Rev. B, 2002, 66: 035418–035423.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zhou, D., Peng, P. & Liu, J. First-principles calculation of dehydrogenating properties of MgH2-V systems. SCI CHINA SER E 49, 129–136 (2006). https://doi.org/10.1007/s11431-006-0129-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11431-006-0129-z