In situ synchrotron radiation powder X-ray diffraction study of the 2LiNH2 + LiH + KBH4 system

[摘要] In the present work we focus on the 2LiNH(2) + KBH4 + LiH system: the phase-structural transformations occurring during the desorption process on the powder mixture are described by in situ synchrotron radiation powder X-ray diffraction (SR-PXD), high-pressure differential scanning calorimetry and manometric measurements. It is observed that LiNH2 transforms into Li2NH during heating, at about 160 degrees C, while the reflections related to KBH4 disappeared at 380 degrees C. At higher temperature, the formation of Li3BN2 is detected, together with an evident increase of the background, ascribable to the presence of a further phase in the molten state. Patterns at room temperature, after cooling down the sample, confirm the presence of Li3BN2 and KH as reported in the theoretical study. For the as prepared mixture it is possible to achieve the theoretical hydrogen gravimetric capacity of 7.4 wt%. (C) 2013 Elsevier B.V. All rights reserved.

[发布日期] 2013-12-15

[关键词] Hydrogen storage in solid state;Complex hydrides;In situ synchrotron radiation powder x-ray diffraction (SR-PXD);Lithium amide;Lithium hydride