Huang Jianmei, Ouyang Liuzhang, Gu Qinfen, Yu Xuebin, Zhu Min
School of Materials Science and Engineering and Key Laboratory of Advanced Energy Storage Materials of Guangdong Province, South China University of Technology, Wushan Road, Tianhe District, Guangzhou 510641 (P.R. China).
Australian Synchrotron, 800 Blackburn Rd., Clayton 3168 (Australia).
Chemistry. 2015 Oct 12;21(42):14931-6. doi: 10.1002/chem.201501461. Epub 2015 Aug 28.
Due to its high hydrogen density (14.8 wt %) and low dehydrogenation peak temperature (130 °C), Zr(BH4 )4 ⋅8 NH3 is considered to be one of the most promising hydrogen-storage materials. To further decrease its dehydrogenation temperature and suppress its ammonia release, a strategy of introducing LiBH4 and Mg(BH4 )2 was applied to this system. Zr(BH4 )4 ⋅8 NH3 -4 LiBH4 and Zr(BH4 )4 ⋅8 NH3 -2 Mg(BH4 )2 composites showed main dehydrogenation peaks centered at 81 and 106 °C as well as high hydrogen purities of 99.3 and 99.8 mol % H2 , respectively. Isothermal measurements showed that 6.6 wt % (within 60 min) and 5.5 wt % (within 360 min) of hydrogen were released at 100 °C from Zr(BH4 )4 ⋅8 NH3 -4 LiBH4 and Zr(BH4 )4 ⋅8 NH3 -2 Mg(BH4 )2 , respectively. The lower dehydrogenation temperatures and improved hydrogen purities could be attributed to the formation of the diammoniate of diborane for Zr(BH4 )4 ⋅8 NH3 -4 LiBH4 , and the partial transfer of NH3 groups from Zr(BH4 )4 ⋅8 NH3 to Mg(BH4 )2 for Zr(BH4 )4 ⋅8 NH3 -2 Mg(BH4 )2 , which result in balanced numbers of BH4 and NH3 groups and a more active H(δ+) ⋅⋅⋅(-δ) H interaction. These advanced dehydrogenation properties make these two composites promising candidates as hydrogen-storage materials.
由于Zr(BH4 )4 ⋅8 NH3具有高氢密度（14.8 wt%）和低脱氢峰温度（130 °C），它被认为是最有前景的储氢材料之一。为了进一步降低其脱氢温度并抑制氨释放，将引入LiBH4和Mg(BH4 )2的策略应用于该体系。Zr(BH4 )4 ⋅8 NH3 -4LiBH4和Zr(BH4 )4 ⋅8 NH3 -2Mg(BH4 )2复合材料的主要脱氢峰分别位于81和106 °C，氢纯度分别高达99.3和99.8 mol % H2。等温测量表明，在100 °C下，Zr(BH4 )4 ⋅8 NH3 -4LiBH4和Zr(BH4 )4 ⋅8 NH3 -2Mg(BH4 )2分别在60分钟内释放出6.6 wt%的氢和在360分钟内释放出5.5 wt%的氢。较低的脱氢温度和提高的氢纯度可归因于Zr(BH4 )4 ⋅8 NH3 -4LiBH4中硼烷二氨合物的形成，以及对于Zr(BH4 )4 ⋅8 NH3 -2Mg(BH4 )2而言，NH3基团从Zr(BH4 )4 ⋅8 NH3部分转移至Mg(BH4 )2，这导致BH4和NH3基团数量平衡以及更活跃的H(δ+) ⋅⋅⋅(-δ) H相互作用。这些先进的脱氢性能使这两种复合材料成为有前景的储氢材料候选者。
