Mixture of LiAlH4and LiNH2 with a molar ratio of 1∶ 2 was ball-milled to form Li-Al-N-H compo site. The prepared composite was heated for dehydrogenation, and the fully dehydrogenated sample was re-hy- drogenated. The dehydrogenation/re-hydrogenation processes were studied by means of XRD, DSC and FTIR analysis. The experimental results show that the dehydrogenation process of LiAlH4/2LiNH2 composite was a three-step reaction, and Li3AlN2 was finally formed after releasing 8. 65％ (mass fraction) hydrogen. Further more, the derived Li3AlN2 can be re-hydrogenated to LiNH2, AlN and LiH under conditions of 10 MPa H2 and 400℃, and 5.0％ ( mass fraction) hydrogen can be reversibly stored by Li3 AlN2. The dehydrogenation/re hydrogenation mechanism of LiAlH4/2LiNH2 composite was also discussed.%将LiAlH4和LiNH2按摩尔比1∶2进行球磨复合,然后将复合物进行加热放氢,对完全放氢后的产物进行再吸氢,系统研究了复合物放氢/再氢化行为.通过X射线衍射(XRD)、差示扫描量热法(DSC)和傅里叶变换红外光谱(FTIR)等测试手段对反应过程进行了分析.结果表明,LiAlH4/2LiNH2复合体系加热放氢分为3个反应阶段,放氢后生成Li3AlN2,总放氢量达到8.65%(质量分数).放氢生成的Li3AlN2在10 MPa氢气压力和400℃条件下,能可逆吸氢5.0%(质量分数),吸氢后的产物为LiNH2,AlN和LiH,而不再生成LiAlH4.对LiAlH4/2LiNH2复合物放氢/再氢化过程机理进行了分析.
展开▼
