球磨时间对掺杂Ce(SO_4)_2的NaAlH_4吸放氢性能的影响  

Effect of Ball-Milling Time on Hydrogenating and Dehydriding Properties of Complex Hydride NaAlH_4 Doped with Ce(SO_4)_2

作　　者：郭世海[1] 王国清[1] 赵栋梁[1] 张羊换[1] 王新林[1] 

机构地区：[1]钢铁研究总院功能材料研究所,北京100081

出　　处：《稀有金属》2011年第6期899-903,共5页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(50701011)资助

摘　　要：采用球磨的方式在NaAlH4中掺入稀土催化剂Ce(SO4)2,通过X射线衍射仪(XRD)、扫描电镜(SEM)及PCT(pressure content tempera-ture)测试仪研究了球磨时间对NaAlH4的相结构和吸放氢性能的影响。结果表明,经过不同时间球磨后,掺杂Ce(SO4)2的NaAlH4样品仍由NaAlH4相和Ce(SO4)2相组成,球磨没有改变样品的相组成。但是样品的放氢温度均降低,并在球磨6 h时达到最大程度,放氢温度下降了40℃。吸氢后的样品中均存在Al,Na3 AlH6和掺杂相Ce(SO4)2,球磨3和6 h的样品还存在NaAlH4相,说明第二步吸氢反应的程度较大。球磨6 h的样品的吸氢性能最好,吸氢量达到3.598%(质量分数)。球磨时间越长,颗粒越细小,颗粒细化是提高样品吸放氢性能的主要原因。但球磨时间过长后,颗粒团聚逐渐严重,吸放氢性能下降。The complex hydride NaAlH4 doping with rare earths（RE） catalyst Ce（SO4）2 was prepared by the ball milling.The effects of ball-milling time on hydrogenating and dehydrogenating properties and phase structures of the complex hydride NaAlH4 were investigated using X-ray diffractometer（XRD）,scanning electron microscopy（SEM） and pressure composition temperature（PCT） apparatus.The results showed that ball-milling time had no effect on phase structures of NaAlH4 samples doped with Ce（SO4）2 through the duration of ball-milling.The dehydrogenating start temperature of NaAlH4 samples decreased with increasing ball-milling time,reaching a maximum value of 40 ℃ at 6 h,and then increased a little with further increasing ball-milling time.The phases of all of the samples after hydrogenation were composed of Al,Na3AlH6 and Ce（SO4）2 and there was NaAlH4 phase in the samples as ball-milling 3 and 6 h,indicating that the second step hydrogen absorption reaction was complete.The sample as ball-milling 6 h had the best hydrogenating property with hydrogenation mass fraction of 3.598%（mass fraction）.The longer the ball-milling time was,the smaller the particle size of the samples.The particle refinement was the main reason to improve the hydrogenating and dehydrogenating properties of NaAlH4.But the particles aggregated seriously as the ball-milling time was too long,which resulted in the degradation of the hydrogenating and dehydrogenating properties of the samples.

关 键 词：金属络合氢化物 球磨时间 NaAlH4 吸放氢性能 

分 类 号：TK91[动力工程及工程热物理]