孔道Al2O3/SiO2对NaAlH4-Tm2O3体系储氢性能的影响

摘要

以机械球磨法制备具有可逆吸放氢性能的NaAlH4-Tm2O3储氢材料体系.利用相同制备方法进一步研究两种不同孔道材料(大孔Al2O3与介孔SiO2)对NaAlH4-Tm2O3体系储氢性能的影响,测试样品的循环吸放氢性能,并对样品吸放氢前后的结构进行表征.结果表明:大孔Al2O3材料的添加并不能明显改善NaAlH4-Tm2O3体系的放氢速率和放氢量,而介孔SiO2的加入使NaAlH4-Tm2O3体系在150℃条件下5h内的首次放氢量(质量分数)达到4.61％,高于NaAlH4-Tm2O3体系的4.27％,增加了约8.0％.此外,添加介孔SiO2的NaAlH4-Tm2O3体系放氢速率也有所提高.%NaAlH4-Tm2O3 hydrogen storage system with reversible capacity was prepared by the ball milling method. The mixtures of two different porous materials (macroporous A12O3 and mesoporous SiO2) and NaAlH4-Tm2O3 were prepared using the same method, and the influence of the two porous materials on NaAlH4-Tm2O3 was investigated. The hydrogen storage capacity and the structure of the samples before and after hydrogen desorption were characterized. The results show that the addition of macroporous A12O3 can not improve the hydrogen release rate and capacity, but with the addition of mesoporous SiO2, NaAlH4-Tm2O3-SiO2 system has the maximum hydrogen release amount of 4.61% (mass fraction), about 8.0% higher than that of NaAlH4-Tm2O3. Furthermore, the hydrogen desorption rate of NaAlH4-Tm2O3 with mesoporous SiO2 is also improved.