Metal‐Borohydride‐Modified Zr(BH4)4⋅8 NH3: Low‐Temperature Dehydrogenation Yielding Highly Pure Hydrogen |
| |
| Authors: | Dr Jianmei Huang Prof?Dr Liuzhang Ouyang Dr Qinfen Gu Prof?Dr Xuebin Yu Prof?Dr Min Zhu |
| |
| Institution: | 1. 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);2. Australian Synchrotron, 800 Blackburn Rd., Clayton 3168 (Australia);3. Department of Materials Science, Fudan University, Handan Road, Yangpu Distric, Shanghai 200433 (P.R. China) |
| |
| Abstract: | 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 Hδ+ ??? ?δH interaction. These advanced dehydrogenation properties make these two composites promising candidates as hydrogen‐storage materials. |
| |
| Keywords: | borohydrides hydrides hydrogen hydrogen storage zirconium |
|
|
