Acta Phys. -Chim. Sin. ›› 2008, Vol. 24 ›› Issue (04): 686-690.doi: 10.3866/PKU.WHXB20080424

• ARTICLE • Previous Articles     Next Articles

Bond Characters and Thermodynamic Stabilities of LiAlH4 and Li3AlH6

LIANG Chu; LI Guang-Xu; LAN Zhi-Qiang; LIU Yi-Xin; WEI Wen-Lou; GUO Jin   

  1. Key Laboratory of National Education Ministry for Nonferrous Metals and Materials Processing Technology, College of Physics Science and Technology, Guangxi University, Nanning 530004, P. R. China
  • Received:2007-10-17 Revised:2007-11-07 Published:2008-04-07
  • Contact: GUO Jin E-mail:guojin@gxu.edu.cn

Abstract: The electronic structures, formation enthalpies, and reaction enthalpies of Li-Al-H system complex were investigated using plane-wave pseudo-potential method based on density functional theory. Calculated cell parameters were in agreement with experiment. The interaction between Al and H atoms was strong covalent bond and the interaction between Li andHatoms was strong ionic bond in both LiAlH4 and Li3AlH6. The calculated reaction enthalpies for reactions (1) LiAlH4→1/3Li3AlH6+2/3Al+H2, (2) 1/3Li3AlH6→LiH+1/3Al+1/2H2, and (3) LiH+Al→LiAl+1/2H2 were 14.3, 14.9, and 50.9 kJ·mol-1 at 298 K, respectively, which were in agreement with experiment results.

Key words: Li-Al-H complex, Electronic structure, Bond character, Thermodynamic stability

MSC2000: 

  • O641