3LiBH4/CeF3体系的放氢性能及机制

采用球磨法制备了3LiBH₄/CeF₃反应体系, 通过压力-组成-温度(PCT)测试仪、 X射线衍射仪(XRD)和傅里叶变换红外光谱仪(FTIR)研究了体系的放氢性能、 反应机制及性能改善机理. 结果表明, 3LiBH₄/CeF₃体系在295 ℃左右快速放氢, 总放氢量为4.1%(质量分数). 放氢过程中CeF₃与LiBH₄直接发生反应: 3LiBH₄+CeF₃1/2CeB₆+1/2CeH₂+3LiF+11/2H₂. 与纯LiBH₄相比, 放氢热力学稳定性和表观活化能的降低是3LiBH₄/CeF₃体系放氢温度下降的主要原因.

Dehydrogenation Property and Mechanism of 3LiBH4/CeF3 System

The 3LiBH4/CeF3 reactive system was prepared by ball-milling treatment. Its dehydrogenation property and reaction as well as the property improvement mechanism were investigated by pressure-composition-temperature( PCT) analyser, X-ray diffractometer( XRD) and Fourier transform infrared spectrometer(FTIR). It was found that the 3LiBH4/CeF3 system fast released hydrogen at about 295 ℃ with about 4. 1%( mass fraction) of hydrogen totally desorbed. During the dehydrogenation process, CeF3 reacted directly with LiBH4 according to the reaction 3LiBH4+CeF3 →1/2CeB6+1/2CeH2+3LiF+11/2H2 . In com-parison with pristine LiBH4 , the decrease in dehydrogenation thermodynamic stability and apparent activation energy are the main reasons for the declined dehydrogenation temperature of the 3LiBH4/CeF3 system.