Dehydriding properties of ¦Ã-AlH₃

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• 作者：Haizhen Liu ; Xinhua Wang ; Zhaohui Dong ; Guozhou Cao ; Yongan Liu ; Lixin Chen ; Mi Yan
• 关键词：Hydrogen storage materials ; Hydrogen storage properties ; Aluminum hydride ; Ball milling ; Dehydriding
• 刊名：International Journal of Hydrogen Energy
• 出版年：2013
• 出版时间：21 August, 2013
• 年：2013
• 卷：38
• 期：25
• 页码：10851-10856
• 全文大小：1167 K

文摘

AlH₃ is a promising hydrogen storage material due to its high hydrogen capacity (10?wt % ) and relatively low dehydriding temperature. In this work, ¦Ã-AlH₃ was prepared by organometallic synthesis method and the effects of ball milling on dehydriding properties of ¦Ã-AlH₃ were investigated systematically. Experimental results shows that as-prepared ¦Ã-AlH₃ releases about 8.3?wt % of hydrogen in the temperature range of 130-160?¡ãC at a heating rate of 2?¡ãC/min. Ball milling significantly improves the dehydriding behavior of ¦Ã-AlH₃. DSC-MS analysis reveals that the dehydriding temperature of ¦Ã-AlH₃ ball-milled for 10?h decreases by around 30?¡ãC. In addition, the dehydriding activation energy of ¦Ã-AlH₃ ball-milled for 2?h decreased from 87 to 68?kJ/mol. Isothermal dehydriding measurements demonstrate that duration needed to release 90 % hydrogen for as-prepared ¦Ã-AlH₃ is 280?min, but it takes only 82?min after ball milled for 10?h to release the same amount of?hydrogen. Moreover, the dehydriding path of ¦Ã-AlH₃ is changed by ball milling. As-prepared ¦Ã-AlH₃ transforms to ¦Á-AlH₃ before dehydriding, while ball-milled ¦Ã-AlH₃ prefers to dehydride directly without firstly transforming to ¦Á-AlH₃.