Model for the Formation Energies of Alanates and Boranates

2006/11/27 by Michiel J. van Setten, M. J. van Setten, G. A. de Wijs +2
Chemistry · Environmental Science · Materials Science · Physics and Astronomy · #Chemical Synthesis and Characterization #Hydrogen Storage and Materials #Radioactive element chemistry and processing #cond-mat.mtrl-sci

paper · pdf · doi:10.1021/jp070039r

published as J. Phys. Chem. C 111 No. 26, 9592 - 9594, (2007) · 3 pages, 2 figures

arxiv created 2006/11/27 · openalex publication_date 2007/06/01 · arxiv updated 2009/12/01 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/01

Abstract

We develop a simple model for the formation energies (FEs) of alkali and alkaline earth alanates and boranates, based upon ionic bonding between metal cations and AlH 4 - or BH 4 - anions. The FEs agree well with values obtained from first principles calculations and with experimental FEs. The model shows that details of the crystal structure are relatively unimportant. The small size of the BH 4 - anion causes a strong bonding in the crystal, which makes boranates more stable than alanates. Smaller alkali or alkaline earth cations do not give an increased FE. They involve a larger ionization potential that compensates for the increased crystal bonding.

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