Mg(BH4)2 exhibits a high hydrogen content of 14.9 wt% and thermodynamic stability in the overall decomposition reaction that corresponds to hydrogen desorption at around room temperature. However, the potential applications in hydrogen storage are restricted by high kinetic barriers. In this study, we show the synthesis of Mg(BH4)2/carbon nanocomposites by ball milling of MgH2 nanoparticles supported on carbon aerogel in a B2H6/H2 atmosphere. The nanocomposite exhibits a lower kinetic barrier as compared to bulk Mg(BH4)2. The temperature for major hydrogen desorption is decreased to 160 °C. Furthermore, re-formation of Mg(BH4)2 after full dehydrogenation is achieved under mild conditions (200 °C and 80 to 150 bar H2) in the nanocomposite. This work demonstrates nanoengineering as an effective approach to realize the reversible hydrogen storage of Mg(BH4)2 under mild conditions.
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机译：Mg（BH4）2的氢含量高达14.9 wt％，并且在整个分解反应中具有热力学稳定性，这与室温附近的氢解吸相对应。然而，在氢存储中的潜在应用受到高动力学势垒的限制。在这项研究中，我们显示了通过在B2H6 / H2气氛中球磨负载在碳气凝胶上的MgH2纳米颗粒来合成Mg（BH4）2 /碳纳米复合材料。与块状Mg（BH4）2相比，纳米复合材料显示出较低的动力学势垒。氢气的主要脱附温度降至160°C。此外，在温和的条件下（200°C和80至150 bar H2）在纳米复合材料中实现了完全脱氢后Mg（BH4）2的重整。这项工作证明了纳米工程是在温和条件下实现Mg（BH4）2可逆储氢的有效方法。
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