RIS ID

116458

Publication Details

Chen, X., Li, R., Xia, G., He, H., Zou, W. & Yu, X. (2017). A comparison study of decomposition mechanisms of single-cation and double-cations (Li, Al) ammine borohydrides. International Journal of Hydrogen Energy, 42 (39), 24861-24867.

Abstract

The decomposition mechanisms of [Li(NH 3 )][BH 4 ], [Al(NH 3 ) 6 ][BH 4 ] 3 and [Al(NH 3 ) 6 ][Li 2 (BH 4 ) 5 ] were investigated using Density functional theory (DFT) calculation. The calculated results show that [Li(NH 3 )][BH 4 ] has low NH 3 vacancy formation energy and diffusion barrier, therefore ammonia would easily release at relatively low temperature. Both [Al(NH 3 ) 6 ][BH 4 ] 3 and [Al(NH 3 ) 6 ][Li 2 (BH 4 ) 5 ] show relatively high NH 3 vacancy formation energies and diffusion barriers, which avoid ammonia release at low temperature. In addition, the calculated H 2 formation energy barriers, i.e., [Al(NH 3 ) 6 ][Li 2 (BH 4 ) 5 ] < [Al(NH 3 ) 6 ][BH 4 ] 3 < [Li(NH 3 )][BH 4 ], are in agreement with the tendency of dehydrogenation temperatures determined experimentally. The incorporation of [BH 4 ] - into [Al(NH 3 ) 6 ][BH 4 ] 3 play an important role in decreasing the dehydrogenation temperature and improving the hydrogen purity of [Al(NH 3 ) 6 ][Li 2 (BH 4 ) 5 ].

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Link to publisher version (DOI)

http://dx.doi.org/10.1016/j.ijhydene.2017.08.100