Hostname: page-component-8448b6f56d-cfpbc Total loading time: 0 Render date: 2024-04-24T16:35:45.448Z Has data issue: false hasContentIssue false
  • English
  • Français

Ab Initio Alloying of Mg for Hydrogen Storage

Published online by Cambridge University Press:  01 February 2011

Deniz Kecik  and
Mehmet Kadri Aydinol
Deniz Kecik
Affiliation:
denizkecik@gmail.com, METU, Metallurgical and Materials Engineering, 142. Sok. No:6 Beysukent, Ankara, 06530, Turkey, +905335207282, +903122102518
Mehmet Kadri Aydinol
Affiliation:
kadri@metu.edu.tr, METU, Metallurgical and Materials Engineering, Middle East Technical University Department of Metallurgical and Materials Engineering, Ankara, 06531, Turkey
Get access

Abstract

A candidate hydrogen storing material should have high storage capacity and fast dehydrogenation kinetics. On this basis, magnesium hydride (MgH2) is an outstanding compound with 7.6 wt% storage capacity, despite its slow dehydriding kinetics and high desorption temperature. Therefore in this study, formation energies of alloyed bulk MgH2, adsorption energies on alloyed magnesium (Mg) and MgH2 surface structures were calculated by total energy pseudopotential methods. Also, the effect of substitutionally placed dopants to the dissociation of hydrogen molecule (H2) at the surface of Mg was investigated via Molecular Dynamics (MD). The results show that 31 out of 32 selected dopants decreased the formation energy of bulk MgH2, within a range of ˜37 kJ/mol-H2 where only Sr did not display any such effect. The most favorable elements in this respect are; P, K, Tl, Si, Sn, Ag and Pb. Moreover, surface adsorption energy values display that all elements are adsorbed substitutionally on the clean (0001) surface of Mg where adsorption on MgH2 (001) surface is possible only for alloying elements other than Zn, Au, In, Ag, Li, Tl, Cd, Na and K. Finally, results of MD simulations point out that the elements giving rise to the dissociation of hydrogen molecule came out to be Ti, V, Cr, Mn, Fe, Co, Ni, Zr, Nb, Mo, Ru, Rh ve Hf.

Keywords

HstorageMg
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1098: Symposium HH – The Hydrogen Economy , 2008 , 1098-HH03-05
Copyright
Copyright © Materials Research Society 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Zuttel, A., Materials Today, 9, 24 33 (2003)Google Scholar
2 Schlapbach, L. and Zuttel, A., Nature, 414 (2001).Google Scholar
3 Song, Y., Guo, Z. X. and Yang, R., Phys. Rev. B, 69, 094205 (2004)Google Scholar
4 Bird, D.M., Clarke, L.J., Payne, M.C. and Stich, I., Chemical Physics Letters, 212, 5 17, (1993).Google Scholar
5 Kresse, G. and Hafner, J., Phys. Rev. B 47, 558 (1993); ibid. 49, 14 251 (1994).Google Scholar
6 Kresse, G. and Furthmuller, J., Comput. Mat. Sci. 6, 15 (1996).Google Scholar
7 Kresse, G. and Furthmuller, J., Phys. Rev. B 54, 11 169 (1996).Google Scholar
8 Perdew, J., Chevary, J., Vosko, S., Jackson, K., Pederson, M., Singh, D., Fiolhais, C.: “Atoms, molecules, solids, and surfaces: Applications of the Generalized Gradient Approximation for Exchange and Correlation.,” Phys. Rev. B, 46, (1992), 6671–6687.Google Scholar
9 Kresse, G. and Hafner, J., J. Phys.: Condens. Matt. 6, 8245 (1994).Google Scholar