Dehydrogenation characteristics of LiAlH₄ improved by in-situ formed catalysts

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• 作者：Jiaxing Cai ; Lei Zang ; Lipeng Zhao ; Jian Liu ; ^{liujian@nankai.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Yijing Wang
• 关键词：Hydrogen storage materials ; Dehydrogenation ; Complex hydrides ; LiAlH4 ; FeCl2 doping ; In-situ formed catalysts
• 刊名：Journal of Energy Chemistry
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：25
• 期：5
• 页码：868-873
• 全文大小：1219 K

文摘

The hydrogen storage properties and catalytic mechanism of FeCl₂-doped LiAlH₄ were investigated in minute details. LiAlH₄-2 mol% FeCl₂ samples start to release hydrogen at 76 °C, which is 64 °C lower than that of as-received LiAlH₄. Isothermal desorption measurements show that the 2 mol% FeCl₂-doped sample releases 7.0 wt% of hydrogen within 17 min at 250 °C. At lower temperatures of 110 °C and 80 °C, the sample can release 4.4 wt% and 3 wt% of hydrogen, respectively. The apparent activation energy of LiAlH₄-2 mol% FeCl₂ samples for R2 is 105.02 kJ/mol, which is 67 kJ/mol lower than that of pure LiAlH₄. The reaction between LiAlH₄ and FeCl₂ during ball milling was found by analyzing the X-ray diffraction results, and Fe-Al particles formed in-situ from the reaction act as the real catalyst for the dehydrogenation of LiAlH₄.