Magnesium borohydride (Mg(BH₄)₂) is widely regarded as a promising hydrogen storage material due to its high capacity; however, it is still challenging to synthesize Mg(BH₄)₂ with low cost. Traditionally, Mg(BH₄)₂ has been mainly produced using other borohydride as the starting materials via exchange reactions. Herein, we report an economical method to synthesize Mg(BH₄)₂ by converting B-O bonds in widely available borates or boric acid to B-H. The borates or boric acid is ball-milled with MgH₂ under ambient conditions to form Mg(BH₄)₂ with high yield (>80%). Mg(BH₄)₂ was also successfully generated by reacting low-cost Mg with boric acid. Compared with previous approaches, this method avoids expensive boron sources such as LiBH₄, NaBH₄, and B₂H₆, and does not require high pressure H₂ gas and high temperatures, and therefore significantly reduces costs. This method could be an alternative to the current Mg(BH₄)₂ synthesis processes.

硼氢化镁(Mg(BH ₄ ) ₂ )因其高容量而被广泛认为是一种很有前途的储氢材料。然而，以低成本合成Mg(BH ₄ ) ₂仍然具有挑战性。传统上，Mg(BH ₄ ) ₂主要使用其他硼氢化物作为原料通过交换反应生产。在此，我们报告了一种通过将广泛可用的硼酸盐或硼酸中的 BO 键转化为BH 来合成 Mg(BH ₄ ) ₂的经济方法。硼酸盐或硼酸在环境条件下与 MgH ₂球磨形成 Mg(BH ₄ ) ₂收率高（>80%）。Mg(BH ₄ ) ₂也可以通过低成本的镁与硼酸反应成功生成。与之前的方法相比，该方法避免了LiBH ₄、NaBH ₄和B ₂ H ₆等昂贵的硼源，并且不需要高压H ₂气体和高温，因此显着降低了成本。该方法可以替代当前的 Mg(BH ₄ ) ₂合成工艺。