Ball-milled Si powder for the production of H2 from water for fuel cell applications
Ball-milled Si powder for the production of H2 from water for fuel cell applications
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DOI：
10.1016/j.ijhydene.2016.05.181
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发表时间：
2016-08
影响因子：
7.2
通讯作者：
Lang Xu;S. Ashraf;Jing-yu Hu;P. Edwards;M. Jones;E. Hadzifejzovic;J. Foord
中科院分区：
文献类型：
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作者：
Lang Xu;S. Ashraf;Jing-yu Hu;P. Edwards;M. Jones;E. Hadzifejzovic;J. Foord
近年来，向小型便携式燃料电池供应氢气的安全技术的发展已成为其部署的重大障碍，解决方案集中在使用氢吸收材料或通过化学反应产生氢气。在目前的工作中，我们证明了在 KOH 和蔗糖存在下，在惰性条件下球磨 Si 会形成细小的 Si 基粉末，该粉末在环境起始温度下与水自发反应，以高产率快速释放氢气。嵌入的KOH能够利用KOH溶解热的自热效应加速硅的水解反应，无需外部加热来引发反应；它还通过使其以可溶性硅酸盐的形式溶解，降低了反应对硅表面氧化物污染的敏感性。此外，可以通过调节环境温度来开启和关闭硅水反应。结果表明，球磨的 KOH 嵌入硅粉能够在有氧条件下与不同的水源（例如自来水、河水和盐水）反应产生 H2。该方法代表了一种向小型燃料电池安全提供氢燃料的廉价可扩展方法。
The development of a safe technique for the supply of hydrogen to small portable fuel cells has emerged as a significant barrier to their deployment in recent years, with solutions centering on the use of hydrogen absorption materials, or the generation of hydrogen through chemical reaction. In the present work we demonstrate that the ball-milling of Si under inert conditions in the presence of KOH and sucrose results in the formation of a fine Si-based powder which reacts spontaneously with water at ambient starting temperature to evolve hydrogen rapidly at high yield. Embedded KOH is capable of accelerating the hydrolysis reaction of silicon by the self-heating effect attributed to dissolution heat of KOH, obviating the need for external heating to initiate the reaction; it also reduces the sensitivity of the reaction to oxide contamination of the Si surface by enabling its dissolution in the form of soluble silicates. Moreover, the silicon–water reaction can be switched on and off by adjusting the ambient temperature. It is shown that ball-milled, KOH-embedded Si powder is able to react with different water sources, such as tap water, river water, and salt water, to produce H2under aerobic conditions. The method represents a cheap scalable approach for the safe provision of hydrogen fuel to small fuel cells.