Efficient Synthesis of Alkali Borohydrides from Mechanochemical Reduction of Borates Using Magnesium–Aluminum-Based Waste
oleh: Thi Thu Le, Claudio Pistidda, Julián Puszkiel, Chiara Milanese, Sebastiano Garroni, Thomas Emmler, Giovanni Capurso, Gökhan Gizer, Thomas Klassen, Martin Dornheim
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2019-09-01 |
Deskripsi
Lithium borohydride (LiBH<sub>4</sub>) and sodium borohydride (NaBH<sub>4</sub>) were synthesized via mechanical milling of LiBO<sub>2</sub>, and NaBO<sub>2</sub> with Mg−Al-based waste under controlled gaseous atmosphere conditions. Following this approach, the results herein presented indicate that LiBH<sub>4</sub> and NaBH<sub>4</sub> can be formed with a high conversion yield starting from the anhydrous borates under 70 bar H<sub>2</sub>. Interestingly, NaBH<sub>4</sub> can also be obtained with a high conversion yield by milling NaBO<sub>2</sub>·4H<sub>2</sub>O and Mg−Al-based waste under an argon atmosphere. Under optimized molar ratios of the starting materials and milling parameters, NaBH<sub>4</sub> and LiBH<sub>4</sub> were obtained with conversion ratios higher than 99.5%. Based on the collected experimental results, the influence of the milling energy and the correlation with the final yields were also discussed.