Ab initio calculations of MgH2, MgH2:Ti and MgH2:Co compounds
Paskaš Mamula, Bojana
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The understanding of hydrogen bonding in magnesium and magnesium based alloys is an important step toward its prospective use. In the present study, a density functional theory (DFT) based, full-potential augmented plane waves method of calculation, extended with local orbitals (FP-APW+lo), was used to investigate the stability of MgH2 and MgH2:TM (TM = Ti and Co) 10 wt% alloys and the influence of this alloying on hydrogen storage properties of MgH2 compound. Effects of a possible spin polarisation induced in the system by transition metal (TM) ions were considered too. It has been found that TM-H bonding is stronger than the Mg-H bond, but at the same time it weakens other bonds in the second and third coordination around a TM atom, which leads to overall destabilization of the MgH2 compound. Due to a higher number of d-electrons, this effect is more pronounced for Co alloying, where in addition, the spin polarisation has a noticeable and stabilising influence on the compound structu...re. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
Keywords:Hydrogen storage / MgH2 / Transition metal catalyst / ab initio calculations
Source:International Journal of Hydrogen Energy, 2010, 35, 2, 598-608
- Ministry of Science and Technological development of Republic of Serbia [141009, 142027]