Hybrid density functional and molecular dynamics study of promising hydrogen storage materials: Double metal amidoboranes and metal amidoborane ammoniates
2012 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 116, no 33, 17351-17359 p.Article in journal (Refereed) Published
In this paper, the recently synthesized materials, Na2Mg-(NH 2BH 3) 4, NaLi(NH 2BH 3) 2, Mg(NH 2BH 3) 2·NH 3, and Ca-(NH 2BH 3) 2·2NH 3, are studied, which were found suitable for hydrogen storage applications. The hybrid density exchange-correlation functional is employed to explore the structural and electronic properties of these materials using the first-principles method on the basis of density functional theory calculations. From the detailed study of electronic structures, it is found that the mixed cation amidoboranes and [NH 3] molecules play an important role in the dehydrogenation process. Bader charge analysis is performed to show the charge distribution between the constituent atoms. The corresponding electron densities and related properties of these compounds are also calculated. Furthermore, ab initio molecular dynamics simulations are performed to study the diffusion of hydrogen in these compounds, which consist of boron, nitrogen, and hydrogen atoms. The common features of these compounds are also revealed by explaining the electronic properties. Finally, it is shown that the mobility of hydrogen in Na 2Mg(NH 2BH 3) 4 and NaLi(NH 2BH 3) 2 is slightly higher than that in Mg(NH 2BH 3) 2·NH 3 and Ca(NH 2BH 3) 2·2NH 3 at the same temperatures.
Place, publisher, year, edition, pages
2012. Vol. 116, no 33, 17351-17359 p.
IdentifiersURN: urn:nbn:se:uu:diva-186758DOI: 10.1021/jp304261fISI: 000307748700006OAI: oai:DiVA.org:uu-186758DiVA: diva2:572914