Comparative Study of Structural Changes in NH3BH3, LiNH2BH3, and KNH2BH3 During Dehydrogenation Process
Comparative Study of Structural Changes in NH3BH3, LiNH2BH3, and KNH2BH3 During Dehydrogenation Process
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DOI：
10.1021/jp212351f
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发表时间：
2012-02
影响因子：
3.7
通讯作者：
K. Shimoda;Koichi Doi;T. Nakagawa;Yu Zhang;H. Miyaoka;T. Ichikawa;M. Tansho;T. Shimizu;A. Bur
中科院分区：
文献类型：
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作者：
K. Shimoda;Koichi Doi;T. Nakagawa;Yu Zhang;H. Miyaoka;T. Ichikawa;M. Tansho;T. Shimizu;A. Bur
使用固态 11B MAS NMR 光谱详细研究了氨硼烷 (AB, NH3BH3)、氨基硼烷锂 (LiAB, LiNH2BH3) 和氨基硼烷钾 (KAB, KNH2BH3) 的热分解途径。在AB的第一次分解过程中，观察到复杂的结构实体，这归因于聚氨基硼烷(PAB，(NH2BH2)n)。另一方面，在第二个过程中形成的聚亚氨基硼烷（PIB，(NHBH)n）在125℃以上显示出单个3倍配位IIIB信号，表明[-B=N-]n网络结构。 LiAB和KAB没有表现出类PAB结构，类PIB结构是通过氢解吸直接形成的。 11B NMR 谱的定量分析表明碱金属氨基硼烷（LiAB、NaAB 和 KAB）热分解的一般路线是相似的。此外，KAB 及其分解产物的 39K MAS NMR 谱表明在氢释放过程中形成了 KH 和无定形 K-N-B-H 相。
The thermal decomposition pathways of ammonia borane (AB, NH3BH3), lithium amidoborane (LiAB, LiNH2BH3), and potassium amidoborane (KAB, KNH2BH3) have been investigated in detail by using solid state 11B MAS NMR spectroscopy. During the first decomposition process of AB, the complex structural entities were observed, which have been attributed to polyaminoborane (PAB, (NH2BH2)n). On the other hand, polyiminoborane (PIB, (NHBH)n) formed in the second process showed a single 3-fold coordination IIIB signal above 125 °C, suggesting a [—B═N—]n network structure. LiAB and KAB did not show the PAB-like structure, and the PIB-like structure was directly formed by the hydrogen desorption. Quantitative analyses of the 11B NMR spectra suggested that the general route of the thermal decomposition of alkali metal amidoboranes (LiAB, NaAB, and KAB) is similar. Also, 39K MAS NMR spectra of KAB and its decomposition products indicated the formation of KH and an amorphous K–N–B–H phase during the hydrogen release.