Large-Scale Synthesis of MgCl2·6NH3 as an Ammonia Storage Material

This Article reveals that magnesium chloride hexammoniate (MgCl2·6NH3) can be prepared by the reaction between magnesium silicide (Mg2Si) and ammonium chloride (NH4Cl) in liquid ammonia, which was developed by Komatsu Electronic Metals Corp. to produce silane (SiH4). The MgCl2·6NH3 product was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry (TGA). XRD study showed that the solid product prepared by the experiment using a Mg2Si/NH4Cl mass ratio of 1:2.8 was phase-pure and highly crystalline MgCl2·6NH3. The FTIR spectrum exhibited the characteristic bands of coordinated ammonia molecules. In addition, the ammonia desorption behavior of the product were investigated by TGA, and its desorption reactions are given in this Article. In summary, this Article provides a new large-scale and low-cost synthesis method to produce MgCl2·6NH3, which has been emerging as an interesting functional material.