Lithium Hydrazinidoborane: A Polymorphic Material with Potential for Chemical Hydrogen Storage

作者：Moury Romain; Demirci Umit B^*; Ban Voraksmy; Filinchuk Yaroslav; Ichikawa Takayuki; Zeng Liang; Goshome Kiyotaka; Miele Philippe

来源：Chemistry of Materials, 2014, 26(10): 3249-3255.

DOI：10.1021/cm500980b

Herein, we describe the synthesis and characterization (chemical, structural, and thermal) of a new crystal phase of lithium hydrazinidoborane (LiN2H4BH3, LiHB), which is a new material for solid-state chemical hydrogen storage. We put in evidence that lithium hydrazinidoborane is a polymorphic material, with a stable low-temperature phase and a metastable high-temperature phase. The former is called beta-LiHB and the latter alpha-LiHB. Results from DSC and XRD showed that the transition phase occurs at around 90 degrees C. On this basis, the crystal structure of the novel beta-LiHB phase was solved. The potential of this material for solid-state chemical hydrogen storage was verified by TGA, DSC, and isothermal dehydrogenations. Upon the formation of the alpha-LiHB phase, the borane dehydrogenates. At 150 degrees C, it is able to generate 10 wt % of pure H-2 while a solid residue consisting of polymers with linear and cyclic units forms. Reaction mechanisms and formation of bis(lithium hydrazide) of diborane [(LiN2H3)(2)BH2](+)[BH4](-) as a reaction intermediate are tentatively proposed to highlight the decomposition of beta-LiHB in our conditions.

• 出版日期2014-5-27