Sodium borohydride formation when Mg reacts with hydrous sodium borates under hydrogen

In this work, we explored the possibility of NaBH4 synthesis when Mg reacted with hydrous sodium borates under hydrogen. It was found that Mg could react with the water in molten hydrous borates to form MgO and release hydrogen, which can be used for NaBH4 synthesis. Then remained Mg would react with formed anhydrous borate to form NaBH4. NaBO2 conversion rate was decreased with increase of the crystalline water content in the hydrous sodium borates. Based on experimental results, a mechanism of NaBH4 formation when Mg reacted with hydrous sodium borates was suggested.