LiAlH₄循环脱氢和再氢化的物理化学途径。

Physiochemical pathway for cyclic dehydrogenation and rehydrogenation of LiAlH4.

作者信息

Wang Jun, Ebner Armin D, Ritter James A

机构信息

Department of Chemical Engineering, Swearingen Engineering Center, University of South Carolina, Columbia, South Carolina 29208, USA.

出版信息

J Am Chem Soc. 2006 May 3;128(17):5949-54. doi: 10.1021/ja060045l.

DOI:10.1021/ja060045l

PMID:16637663

Abstract

A five-step physiochemical pathway for the cyclic dehydrogenation and rehydrogenation of LiAlH4 from Li3AlH6, LiH, and Al was developed. The LiAlH4 produced by this physiochemical route exhibited excellent dehydrogenation kinetics in the 80-100 degrees C range, providing about 4 wt % hydrogen. The decomposed LiAlH4 was also fully rehydrogenated through the physiochemical pathway using tetrahydrofuran (THF). The enthalpy change associated with the formation of a LiAlH4.4THF adduct in THF played the essential role in fostering this rehydrogenation from the Li3AlH6, LiH, and Al dehydrogenation products. The kinetics of rehydrogenation was also significantly improved by adding Ti as a catalyst and by mechanochemical treatment, with the decomposition products readily converting into LiAlH4 at ambient temperature and pressures of 4.5-97.5 bar.

摘要

开发了一种从Li3AlH6、LiH和Al进行LiAlH4循环脱氢和再氢化的五步物理化学途径。通过这种物理化学路线生产的LiAlH4在80-100摄氏度范围内表现出优异的脱氢动力学，提供约4 wt%的氢。分解后的LiAlH4也通过使用四氢呋喃（THF）的物理化学途径完全再氢化。与在THF中形成LiAlH4·4THF加合物相关的焓变在促进从Li3AlH6、LiH和Al脱氢产物的这种再氢化中起了关键作用。通过添加Ti作为催化剂和进行机械化学处理，再氢化的动力学也得到了显著改善，分解产物在环境温度和4.5-97.5 bar的压力下很容易转化为LiAlH4。