Interaction between Lithium Amide and Lithium Hydride

Abstract

Pure lithium amide (LiNH2) decomposes to lithium imide and ammonia at temperatures above 300 °C. Lithium hydride, on the other hand, liberates hydrogen at temperatures above 550 °C. By thoroughly mixing these two substances and conducting temperature-programmed desorption (TPD), we noticed that hydrogen was produced at temperatures around 150 °C. Combined thermogravimetric (TG), X-ray diffraction (XRD), and infrared (IR) analysis revealed that lithium amide would react with lithium hydride and convert to hydrogen and lithium imide (or Li-rich imide). The reaction mechanism was investigated by isotopic exchange.