Improved hydrogen desorption properties of ammonia borane by Ni-modified metal-organic frameworks
Improved hydrogen desorption properties of ammonia borane by Ni-modified metal-organic frameworks
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DOI：
10.1016/j.ijhydene.2011.02.102
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发表时间：
2011-06
期刊：
影响因子：
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通讯作者：
X. Si;Lixian Sun;F. Xu;Chengli Jiao;Fen Li;Shu-Sheng Liu;Jian Zhang;Li-fang Song;C. Jiang;Shuangwei Wang;Yingliang Liu;Y. Sawada
中科院分区：
文献类型：
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作者：
X. Si;Lixian Sun;F. Xu;Chengli Jiao;Fen Li;Shu-Sheng Liu;Jian Zhang;Li-fang Song;C. Jiang;Shuangwei Wang;Yingliang Liu;Y. Sawada
硼烷氨（AB）因其低分子量和异常高的重量氢容量而引起了广泛的研究。然而，AB 的缓慢动力学、不可逆性以及易形成挥发性物质（环硼氮烷和氨）限制了其实际应用。本文开发了在金属有机骨架MIL-101（表示为AB/MIL-101）或Ni改性MIL-101（表示为AB/Ni@MIL-101）中掺杂AB的新储氢策略。在AB/MIL-101样品中，脱氢没有出现任何诱导期和不需要的副产物环硼氮烷，并且分解热力学和动力学得到改善。对于AB/Ni@MIL-101，AB脱氢的峰值温度转移至75°C，这是AB分解温度如此大幅降低（40°C）的首次报道。此外，未检测到对质子交换膜燃料电池有害的环硼氮烷和氨排放。基于理论计算和实验讨论了 AB 和 MIL-101 之间的相互作用。结果表明，AB/MIL-101纳米复合材料中产生了Cr-N和B-O键，AB的分解机理发生了变化。
Ammonia borane (AB) has attracted intensive study because of its low molecular weight and abnormally high gravimetric hydrogen capacity. However, the slow kinetics, irreversibility, and formation of volatile materials (borazine and ammonia) of AB limit its practical application. In this paper, new strategies by doping AB in metal-organic framework MIL-101 (denoted as AB/MIL-101) or in Ni modified MIL-101 (denoted as AB/Ni@MIL-101) are developed for hydrogen storage. In AB/MIL-101 samples, dehydrogenation did not present any induction period and undesirable by-product borazine, and decomposition thermodynamics and kinetics are improved. For AB/Ni@MIL-101, the peak temperature of AB dehydrogenation was shifted to 75 °C, which is the first report of such a big decrease (40 °C) in the decomposition temperature of AB. Furthermore, borazine and ammonia emissions that are harmful for proton exchange membrane fuel cells, were not detected. The interaction between AB and MIL-101 is discussed based on both theoretical calculations and experiments. Results show that Cr–N and B–O bonds have generated in AB/MIL-101 nanocomposites, and the decomposition mechanism of AB has changed.