Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (06): 1537-1542.doi: 10.3866/PKU.WHXB20110617

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

LiMn(BH4)3/2LiCl Composite Synthesized by Reactive Ball-Milling and Its Dehydrogenation Properties

FANG Fang, LI Yong-Tao, SONG Yun, ZHA Jun, ZHAO Bin, SUN Da-Lin   

  1. Department of Materials Science, Fudan University, Shanghai 200433, P. R. China
  • Received:2011-01-12 Revised:2011-03-11 Published:2011-05-31
  • Contact: SUN Da-Lin E-mail:dlsun@fudan.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51001028), Shanghai Natural Science Foundation, China (10ZR1404300), and Fundamental Research Funds for the Central Universities, China.

Abstract:

A LiMn(BH4)3/2LiCl composite was prepared by reactive ball-milling a mixture of LiBH4 and MnCl2, and its dehydrogenation properties were investigated. The results indicate that the LiMn(BH4)3/2LiCl composite consists of crystalline LiCl and amorphous LiMn(BH4)3, and decomposes at 135-190 °C with an activation energy of 114.0 kJ·mol-1, resulting in an emission of 7.0% (w) gas. The released gases contain 96.0% H2 and 4.0% B2H6 (mole fraction, x), which is the reason for why the mass loss of the LiMn(BH4)3/2LiCl composite is larger than that of theoretical hydrogen capacity of 6.3% (w). Moreover, the influence of various Ti-containing dopants on the decomposition of the LiMn(BH4)3/2LiCl composite was studied. We found that among TiF3, TiC, TiN, and TiO2, only TiF3 achieved a reduction in decomposition temperature. Compared with the undoped LiMn(BH4)3/2LiCl composite, the onset decomposition temperature and the activation energy of the TiF3-doped composite are reduced to 125 °C and to 104.0 kJ·mol-1, respectively. These are attributed to the formation of Ti(BH4)3 in some local regions of the TiF3-doped composite by the partial substitution of Ti for Li in LiMn(BH4)3.

Key words: Borohydride, Reactive ball-milling, LiMn(BH4)3, Dehydrogenation property, Catalysis

MSC2000: 

  • O643