Density Functional Studies on Crystal Structure and electronic properties of Potassium Alanate as a candidate for Hydrogen storage

Document Type : Research Paper

Authors

1 Renewable Energies, Magnetism and Nanotechnology Research Laboratory; Department of Physics, Ferdowsi University of Mashhad

2 Department of Materials Science and Engineering,. Carnegie Mellon University, Pittsburgh, Pa USA

Abstract

Potassium Alanate is one of the goal candidates for hydrogen storage during past decades. In this report, initially the Density Functional Theory was applied to simulate the electronic and structural characteristic of the experimentally known KAlH4 complex hydride. The relaxation of unit cell parameters and atomic positions was performed until the total residual force reduced less than 0.001ev per unit cell. The final deduced cell parameters of this orthorhombic structure were a=8.834, b=5.763, c=7.328A˚. Calculations were carried out by using Projected Augmented Plane wave method via QUANTUM ESPRESSO Package. In the next step, the Density of States calculations together with band structure results, showed that our data coincide with a non-magnetic KAlH4 insulator with a band gap of 5.1ev. In order to investigate the nature of chemical bonds in the crystal structure, the charge density distribution in (100),(010),(001),(110) planes, along with Born Effective charge and Löwdin population was used. The results show the transition of a partial charge from K+ cation to [AlH4]- subunit which leads to an ionic bond.

Keywords

Main Subjects

References

  1. U.S. Department of Energy, http://www1.eere.energy.gov/hydrogenandfuelcells/storage/pdfs/targets_onboard_hydro_storage_explanation
  2. Schlapbach, L.; Zuttel, A. Hydrogen-Storage Materials for Mobile Applications. Nature, 2001, 414: 353.
  3. I.P. Jain, Pragya Jain, Ankur Jain, Novel hydrogen storage materials: A review of lightweight complex hydrides, Journal of Alloys and Compounds, 2010, 503: 303.
  4. Bogdanovic, B. & Schwickardi, M. Ti-doped alkali metal aluminium hydrides as potential novel reversible hydrogen storage materials.  J. Alloys Compounds, 1997, 253:1.
  5. D. Pukazhselvan, Duncan Paul Fagg, O.N. Srivastava, One step high pressure mechanochemical synthesis of reversible alanates NaAlH4 and KAlH4, Int. J Hydrogen Energy, 2015, 40:4916.
  6. Mikheeva, V. I.; Troyanovskaya, E. A. "Solubility of Lithium Aluminum Hydride and Lithium Borohydride in Diethyl Ether". Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1971, 20 (12): 2497.
  7. Lei Zang; Jiaxing Cai; Lipeng Zhao; Wenhong Gao; Jian Liu; Yijing Wang, Improved hydrogen storage properties of LiAlH4 by mechanical, J. Alloys Compd., 2015, 647: 756.
  8. Chia-Yen Tan; Wen-Ta Tsai, Catalytic and inhibitive effects of Pd and Pt decorated MWCNTs on the dehydrogenation behavior of LiAlH4, 2015, Int. J Hydrogen Energy, 40:10185.
  9. Lene Mosegaard Arnbjerg, Torben R. Jensen , New compounds in the potassium-aluminium-hydrogen system observed during release and uptake of hydrogen, Int. J. Hyd. Energy, 37, 2012: 345.
  10. Jose R. Ares; Aguey-Zinsou, K.; Leardini, .F.; Jımenez Ferrer, I.; Fernandez, J.; Guo, Z.;  Carlos Sanchez J., “Hydrogen Absorption/Desorption Mechanism in Potassium Alanate (KAlH4) and Enhancement by TiCl3 Doping”, Phys. Chem. C, 2009, 113: 6845.
  11. Morioka H., Kakizaki K., Sai-Cheong Chung, Yamada A., Reversible hydrogen decomposition of KAlH4, J. Alloys Compd., 2003, 353: 310.
  12. Vajeeston, P., Ravindran, P., Kjekshus, A., Fjellvåg, H., Crystal structure of KAlH4 from first principle calculations, J. Alloys Compd., 2004, L8: 363.
  13. G. Kresse, J. Hafner, Phys. Rev. B 47 (1993) R6726; G. Kresse, J. Furthmuller, Comput. Mater. Sci. 1996, 6:15
  14. Hai-Chen Wang, Jie Zheng, Dong-Hai Wu, Liu-Ting Wei, Bi-Yu Tang, Crystal feature and electronic structure of novel mixed alanate LiCa(AlH4)3: a density functional theory investigation, RSC Adv., 2015, 5: 16439.
  15. Hohenberg, Pierre; Walter Kohn, "Inhomogeneous electron gas". Physical Review, 1964, 136 (3B): B864
  16. P. Giannozzi, et al., J.Phys.:Condens.Matter, , 2009, 21, 395502 http://dx.doi.org/10.1088/0953-8984/21/39/395502.
  17. Blochl PE., Projector augmented-wave method, Phys Rev B, 1994, 50:17953.
  18. We used the Pseudopotentials K.pbe-spn-kjpaw_psl.0.2.3.UPF,  Al.pbe-n-kjpaw_psl.0.1.UPF And H.pbe-kjpaw_psl.0.1.UPF from http://www.quantum-espresso.org
  19. Monkhorst H J, Pack J D, Special points for Brillouin-zone integrations, Phys. Rev. B, 1976, 13:5188.
  20. Head J D, Zerner M C, A Broyden-Fletcher-Goldfarb-Shanno optimization procedure for molecular geometries, Chem. Phys. Lett., 1985, 122:264.
  21. Peter E. Blöchl, O. Jepsen, O. K. Andersen, Improved tetrahedron method for Brillouin-zone integrations, Phys. Rev. B, 1994, 49: 16223.
  22. Chung S., Morioka H., Thermochemistry and crystal structures of lithium, sodium and potassium alanates as determined by ab initio simulations, J. Alloys Compd., 2004, 372: 92.
  23. Lowdin, P. O., On the Non‐Orthogonality Problem Connected with the Use of Atomic Wave Functions in the Theory of Molecules and Crystals, 1950, 18: 365.
  24. A. Szabo and N. S. Ostlund, Modern Quantum Chemistry, Dover, 1996.
  25. M. V. Berry, Quantal Phase Factors Accompanying Adiabatic Changes, Royal Society A, 1984, 392: 45.
  26. Mulliken, R. S., Electronic Population Analysis on LCAO-MO Molecular Wave Functions, The J. Chem. Phys,1995, 23(10): 1833.
  27. Vajeeston, P.; Ravindran, P.; Kjekshus, A.; Fjellvag, H., Theoretical modeling of hydrogen storage materials: Prediction of structure, chemical bond character, and high-pressure behavior, J. Alloys Compd. 2005, 77: 404.
  28. O. M. Løvvik , P. N. Molin, Density-functional band-structure calculations of magnesium alanate Mg(AlH4)2, Phys. Rev. B, 2005, 72: 073201.
  29. Becke, A. D., Edgecombe, K. E., A simple measure of electron localization in atomic and molecular systems, J. Chem. Phys., 1990, 92: 5397.
Hydrogen, Fuel Cell & Energy Storage
Volume 2, Issue 3 - Serial Number 7
August 2015
Pages 169-179

Files

Share

How to cite

Statistics