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主要研究氩气气氛下通过机械球磨方法制备的掺杂两种稀土氧化物(由0~5mol%CeO2和 Y2O3)对NaAlH4放氢性能的影响。PCT测试结果显示,在相同的条件下,两种稀土氧化物引起 NaAlH4的最大放氢量和平均放氢速率的规律相似,都随着掺量的增加先增大至某一值后又开始减小。相对于 Y2O3,CeO2对NaAlH4的催化效果影响更为突出,达到相同的放氢量 4.8wt%时,1mol%CeO2-NaAlH4的放氢速率明显比1mol% Y2O3-NaAlH4要高。SEM分析结果显示,随着催化剂含量的增加,粉体颗粒更加均匀,继而团聚成絮状。同时研究发现,球磨后呈分散结构的颗粒可能比絮状结构颗粒反应接触面积大,且经过加热放氢后的试样有很多类似于蜂窝状的气孔存在。
The effects of doping two kinds of rare earth oxides (containing 0-5 mol% CeO2 and Y2O3) on the dehydrohalogenation performance of NaAlH4 were studied by argon gas atmosphere milling. PCT test results show that under the same conditions, the two kinds of rare earth oxides caused by NaAlH4 the maximum amount of hydrogen release and the average rate of hydrogen release similar to the law, with the increase in the content of the first increase to a certain value and then began to decrease small. Compared with Y2O3, the effect of CeO2 on the catalytic effect of NaAlH4 is more prominent. When the same amount of hydrogen released is 4.8wt%, the rate of hydrogen evolution of 1mol% CeO2-NaAlH4 is obviously higher than that of 1mol% Y2O3-NaAlH4. The results of SEM analysis showed that with the increase of catalyst content, the powder particles were more uniform and then aggregated into flocculent. At the same time, it was found that the particles with dispersed structure after ball milling may have larger contact area than flocculent particles, and there are many pores similar to honeycomb in the sample after heating and discharging.