The hydrolysis of MgH delivers high hydrogen capacity (15.2 wt%), which is very attractive for real-time hydrogen supply. However, the formation of a surface passivation Mg(OH) layer and the large excess of HO required to ensure complete hydrolysis are two key challenges for the MgH hydrolysis systems. Now, a low-cost method is reported to synthesize MgH@Mg(BH) composite via ball-milling MgH with cheap and widely available BO (or B(OH)). By adding small amounts of BO, the formed Mg(BH) could significantly promote the hydrolysis of MgH. In particular, the MgH–10 wt% BO composite releases 1330.7 mL·g H (close to 80% theoretical hydrogen generation H) in HO and 1520.4 mL·g H (about 95%) in 0.5 M MgCl in 60 min at 26 °C with hydrolysis rate of 736.9 mL·g·min and 960.9 mL·g·min H during the first minute of the hydrolysis, respectively. In addition, the MgCl solution allows repeated use by filtering and exhibits high cycle stability (20 cycles), therefore leading to much reduced capacity loss caused by the excess HO. We show that by introducing BO and recycling the 0.5 M MgCl solution, the system hydrogen capacity can approach 5.9 wt%, providing a promising hydrogen generation scheme to supply hydrogen to the fuel cells.

中文翻译：

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原位形成的 Mg(BH4)2 用于改善 MgH2 的水解性能

MgH的水解提供了高氢容量（15.2 wt%），这对于实时供氢非常有吸引力。然而，表面钝化 Mg(OH) 层的形成和确保完全水解所需的大量 H2O 是 MgH 水解系统面临的两个关键挑战。现在，报道了一种低成本方法，通过球磨 MgH 与廉价且广泛使用的 BO（或 B(OH)） 合成 MgH@Mg(BH) 复合材料。通过添加少量的BO，形成的Mg(BH)可以显着促进MgH的水解。特别是，MgH2-10 wt% BO复合材料在26°C下60分钟内在H2O中释放1330.7 mL·g H2（接近理论产氢量的80% H2），在0.5 M MgCl2中释放1520.4 mL·g H2（约95%）。 C 的水解速率分别为 736.9 mL·g·min 和 960.9 mL·g·min H 在水解的第一分钟内。此外，MgCl溶液允许通过过滤重复使用，并表现出高循环稳定性（20个循环），因此大大减少了过量H2O引起的容量损失。我们表明，通过引入 BO 并回收 0.5 M MgCl 溶液，系统氢气容量可以接近 5.9 wt%，为向燃料电池供应氢气提供了一种有前途的制氢方案。