Promoted hydrolysis performances and mechanism of Si-NaBH4-AlCl3 in deionized water

• Published in: Chinese journal of chemical engineering 2020-12, Vol.28 (12), p.3136-3144
• Main Authors: Feng, Zhao, Wu, Chaoling, Zhong, Shuang, Chen, Yungui, Chen, Hui, Wang, Yao
• Format: Article
• Language: English
• Subjects: Hydrogen generation; Hydrolysis; Si-NaBH4-AlCl3 composite; Synergetic effect
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/j.cjche.2020.08.019

Si-based hydrolysis material system can be used in mobile/portable hydrogen source applications connected to fuel cells but is limited by alkaline solutions. In the present research, we reported an acid/alkaline free hydrolysis system combining silicon with NaBH4. Samples with different ratios between Si and NaBH4 are prepared via high energy ball milling and hydrolyzed in deionized water at different temperatures. Synergetic effect between silicon and NaBH4 was found in the hydrolysis process. 2Si-NaBH4 sample displays the best hydrolysis performances with the hydrogen yield of 1594 ml⋅g−1 in deionized water at 70 °C. Thereafter, AlCl3 is added into the 2Si-NaBH4 sample to further improve its comprehensive properties. The effect of AlCl3 content and promotion mechanism of the reaction are explored. 2Si-NaBH4–5 wt% AlCl3 sample shows a significant improvement with a high hydrogen yield of 1689 ml·g−1 in deionized water at 70 °C and a corresponding conversion rate of 95.8%, indicating that the Si-NaBH4-AlCl3 composite is promising to be a hydrogen source in applications of mobile/portable fuel-cell-powered facilities. [Display omitted]