掺杂稀土类催化剂对LiAlH4放氢性能和相结构的影响

Effect of Doping RE Catalysts on Dehydriding Properties and Phase Structuresof Complex Hydride LiAlH4

摘要:

采用球磨的方式在LiAlH4中分别掺入3种稀土催化剂LaCl3、CeCl3和Ce(SO4)2，研究了稀土催化剂对LiAlH4的相结构和放氢性能的影响。结果表明，在球磨过程中，掺杂Ce(SO4)2对LiAlH4的分解基本没有影响，而掺杂LaCl3和CeCl3则造成LiAlH4部分分解，产生了LiCl和Al3RE（RE=La，Ce）相。在LiAlH4放氢反应中，稀土催化剂的加入均使LiAlH4初始放氢温度降低，特别是Ce(SO4)2使第1步的放氢温度降低了约25 ℃。稀土催化剂有助于加快LiAlH4分解反应速率，提高LiAlH4的放氢性能。

Abstract:

The complex hydride LiAlH4 doped with rare earths (RE) catalysts of LaCl3, CeCl3 and Ce(SO4)2, respectively were prepared by ball milling. The effects of RE catalysts on the dehydriding properties and phase structures of the complex hydride LiAlH4 were investigated. The results show that the doped Ce(SO4)2 has little effect on the dehydrogenation of LiAlH4 in the ball milling process. However, the doped LaCl3 and CeCl3 cause dehydrogenation of the partial LiAlH4, resulting in LiCl and Al3RE (RE=La, Ce). The doped RE catalysts decrease the dehydriging start temperature of LiAlH4, especially Ce(SO4)2, which decreases the dehydriging start temperature by about 25 oC. RE catalysts help to speed up the decomposition reaction rate of LiAlH4 and improve the dehydriding properties of LiAlH4