Synergistic hydrogen desorption of HCS MgH₂?+?LiAlH₄ composite

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• 作者：Xiangqian Ding ; Yunfeng Zhu ; ^{yfzhu@njut.edu.cn} ; Lingjun Wei ; Ying Li ; Liquan Li
• 关键词：Hydriding combustion synthesis ; MgH2 ; LiAlH4 ; Hydrogen storage ; Destabilization mechanism
• 刊名：Energy
• 出版年：2013
• 出版时间：15 June, 2013
• 年：2013
• 卷：55
• 期：Complete
• 页码：933-938
• 全文大小：1145 K

文摘

MgH₂ was prepared by HCS (hydriding combustion synthesis) method, and the as-prepared product (HCS MgH₂) was further combined with LiAlH₄ by mechanical milling in order to form a new composite of HCS MgH₂?+?LiAlH₄. Structural and hydrogen storage properties of the HCS MgH₂?+?LiAlH₄ composite have been investigated systematically by XRD (X-ray diffraction), SEM (scanning electron microscope), DSC (differential scanning calorimetry) and hydrogenation/dehydrogenation measurements. A mutual destabilization effect has been observed between HCS MgH₂ and LiAlH₄ during hydrogen desorption. The dehydrogenation mechanism of the composite has been revealed. Compared with commercial MgH₂ (Com MgH₂)?+?LiAlH₄ composite, the HCS MgH₂?+?LiAlH₄ composite shows more pronounced synergistic hydrogen desorption with notably decreased dehydrogenation temperature owing to the unique microstructures of the HCS MgH₂, which may provide favorable channels for diffusion of hydrogen atoms and promote synergistic hydrogen desorption of the composite. The dehydrogenation barrier of the HCS MgH₂?+?LiAlH₄ composite is lower than that of the Com MgH₂?+?LiAlH₄ composite. Moreover, the HCS MgH₂?+?LiAlH₄ composite exhibits fast re-hydrogenation kinetics in the first two cycles.