Enhanced hydrogen storage properties of 2LiBH4-LiAlH4 nanoconfined in resorcinol formaldehyde carbon aerogel
Enhanced hydrogen storage properties of 2LiBH4-LiAlH4 nanoconfined in resorcinol formaldehyde carbon aerogel
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DOI：
10.1016/j.jallcom.2017.07.080
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发表时间：
2017-12
影响因子：
6.2
通讯作者：
He Zhou;Xinhua Wang;Haizhen Liu;Mi Yan
中科院分区：
文献类型：
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作者：
He Zhou;Xinhua Wang;Haizhen Liu;Mi Yan
本文合成了间苯二酚甲醛碳气凝胶（RFC），并将其作为纳米级2LiBH 4-LiAlH 4复合材料的支架材料。采用两步熔融渗透法将LiBH 4和LiAlH 4纳米封入到间苯二酚甲醛碳气凝胶的孔中。通过XRD、FTIR分析和BET测量研究了微观结构的演变。通过TPD、TG/DSC/MS等测试手段研究了其储氢性能。实验结果表明，熔体浸渗后，LiBH 4和LiAlH 4在支架中分散良好。纳米约束的2LiBH 4-LiAlH 4复合材料（记为2LiBH 4-LiAlH 4/RFC）表现出两步脱氢过程。这两个步骤的起始脱氢温度分别为100 °C和280 °C，这比研磨的2LiBH 4-LiAlH 4混合物的起始脱氢温度低70 °C和170 °C。在第二步脱氢过程中AlB 2的形成改变了LiBH 4的反应途径。与LiBH 4和LiAlH 4的物理混合物相比，复合物的动力学性能大大增强。纳米限制和AlB 2的形成对纳米限制的2LiBH 4-LiAlH 4/RFC储氢性能的改善具有综合作用。它可以在350 °C和5 MPa H2下再氢化。可逆储氢容量为5.7重量%，实现了。
Resorcinol formaldehyde carbon aerogel (RFC)was synthesized in this paper to be used as a scaffold for nanoconfining 2LiBH4-LiAlH4composite. LiBH4and LiAlH4were nanoconfined into the pores of the prepared resorcinol formaldehyde carbon aerogel by a two-step melt-infiltration process. The microstructure evolution was investigated by XRD, FTIR analysis, and BET measurements. The hydrogen storage properties were studied by TPD, TG/DSC/MS measurements. The experimental results show that LiBH4and LiAlH4are well dispersed in the scaffold after the melt infiltration process. The nano-confined 2LiBH4-LiAlH4composite (denoted as 2LiBH4-LiAlH4/RFC) shows a two-step dehydrogenation process. The onset dehydrogenation temperatures for the two steps are 100 °C and 280 °C, respectively, which are 70 °C and 170 °C lower than that of the milled 2LiBH4-LiAlH4mixture. The formation of AlB2during the second dehydrogenation step alters the reaction pathway of LiBH4. The kinetic properties of the composite are greatly enhanced compared to the physical mixture of LiBH4and LiAlH4. The nanoconfinement and the formation of AlB2have a combined effect on the improvement of hydrogen storage properties for nanoconfined 2LiBH4-LiAlH4/RFC. It could be rehydrogenated at 350 °C and 5 MPa H2. A reversible hydrogen storage capacity of 5.7 wt.% is achieved.