Ammonia borane as hydrogen storage materials
Ammonia borane as hydrogen storage materials
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DOI：
10.1016/j.ijhydene.2018.02.190
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发表时间：
2018-10-04
影响因子：
7.2
通讯作者：
Ozkar, Saint
中科院分区：
文献类型：
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作者：
Akbayrak, Serdar;Ozkar, Saint
氨硼烷的氢含量高达19.6% wt.，在环境条件下稳定性高，无毒，在普通溶剂中溶解度高，是一种合适的固体储氢材料。水解氨硼烷似乎是释放储存在其中的氢的最有效的方法。由于氨硼烷在水溶液中具有相对稳定的抗水解性能，因此在室温下，只有在合适的催化剂存在下，其水解脱氢才能以可观的速率实现。金属(0)纳米颗粒对氨硼烷释放H-2具有较高的初始催化活性。热力学不稳定的金属(0)纳米颗粒可以通过在溶液中使用配体或在固体状态下支持具有大表面积的固体材料表面来实现动力学稳定，防止团聚。从我们自己的研究中给出了这两种稳定化的例子。结果表明，分散在溶液中或负载在合适的大表面积固体材料上的金属(0)纳米颗粒可以在室温下催化硼烷氨中H-2的释放。由阴离子或聚合物在液相中稳定的金属(0)纳米粒子的分散似乎比支撑在固体表面上的金属纳米粒子提供更多的活性位点。然而，与分散在液相中的金属纳米颗粒相比，负载型金属纳米颗粒具有更稳定的抗团聚性能。因此，负载在固体材料上的金属纳米颗粒通常比分散在溶液中的金属纳米颗粒寿命更长。从文献中举例说明了如何通过选择合适的稳定剂或支撑材料来提高金属纳米颗粒的催化活性和耐久性。目前，纳米陶瓷负载的铑(0)纳米颗粒是最活跃的催化剂，在室温下从硼氨中释放H-2的周转频率为2010 min（-1）。(C) 2018氢能源出版有限责任公司，由爱思唯尔有限公司出版。版权所有。
Ammonia borane is an appropriate solid hydrogen storage material because of its high hydrogen content of 19.6% wt., high stability under ambient conditions, nontoxicity, and high solubility in common solvents. Hydrolysis of ammonia borane appears to be the most efficient way of releasing hydrogen stored in it. Since ammonia borane is relatively stable against hydrolysis in aqueous solution, its hydrolytic dehydrogenation can be achieved at an appreciable rate only in the presence of suitable catalyst at room temperature. Metal(0) nanoparticles have high initial catalytic activity in releasing H-2 from ammonia borane. Thermodynamically instable metal(0) nanoparticles can kinetically be stabilized against agglomeration either by using ligands in solution or by supporting on the surface of solid materials with large surface area in solid state. Examples of both type of stabilization are presented from our own studies. The results show that metal(0) nanoparticles dispersed in solution or supported on suitable solid materials with large surface area can catalyze the release of H-2 from ammonia borane at room temperature. Dispersion of metal(0) nano particles, stabilized in liquid phase by anions or polymers, seems advantageous as providing more active sites compared to the metal nanoparticles supported on a solid surface. However, the supported metal nanoparticles are found to be more stable against agglomeration than the ones dispersed in liquid phase. Therefore, metal nanoparticles supported on solid materials have usually longer lifetime than the ones dispersed in solution. Examples are given from the own literature to show how to improve the catalytic activity and durability of metal nanoparticles by selecting suitable stabilizer or supporting materials for certain metal. For the time being, nanoceria supported rhodium(0) nano particles are the most active catalyst providing a turnover frequency of 2010 min(-1) in releasing H-2 from ammonia borane at room temperature. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.