Improved hydrogen storage performance of Mg(NH₂)₂/LiH mixture by addition of carbon nanostructured materials

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• 作者：Rohit R. Shahi ; Himanshu Raghubanshi ; M.A. Shaz ; O.N. Srivastava
• 关键词：Hydrogen storage ; Complex hydride ; Carbon nanostructures ; Catalysts
• 刊名：International Journal of Hydrogen Energy
• 出版年：2013
• 出版时间：17 July, 2013
• 年：2013
• 卷：38
• 期：21
• 页码：8863-8871
• 全文大小：2684 K

文摘

The effect of different carbon nanostructures specifically carbon nanotubes (CNTs) and carbon nanofibers (CNFs) on the improvement of the de/re-hydrogenation characteristics of a Mg(NH₂)₂/LiH mixture have been studied. Amongst CNTs and CNFs, the improvement in the hydrogenation properties for the Mg(NH₂)₂/LiH mixture is higher when CNFs are used as a catalyst. Investigations are also focused on the deployment of two different types of CNF (a) CNF1 (synthesized using a ZrFe₂ catalyst) and (b) CNF2 (synthesized using a LaNi₅ catalyst). The results show that CNF2 is better. The maximum decomposition temperature for the pristine Mg(NH₂)₂/LiH mixture is found to be ¡«250?¡ãC, which is reduced to ¡«180 and ¡«150?¡ãC for the sample mixed with 4?wt % of multi-walled carbon nanotubes (MWCNTs) and CNF2 respectively. The activation energy for the dehydrogenation reaction is found to be 74 and 68?kJ?mol^?1 for the samples mixed with MWCNT and CNF2 respectively, whereas the activation energy for the dehydrogenation reaction of the pristine Mg(NH₂)₂/LiH mixture is 97?kJ?mol^?1. The catalytic activity and the de/re-hydrogenation characteristics of the Mg(NH₂)₂/LiH mixture mixed with different carbon nanostructures are described and discussed.