Ca-Na-N-H system for reversible hydrogen storage

Ca-Na-N-H system was introduced and evaluated in this paper for reversible hydrogen storage. Similar to other amide-hydride systems already reported, interaction between Ca(NH2)2-NaH (1/1) was observed in the temperature range of 120-270 °C with 1.1 wt% of hydrogen desorption, from which 0.96 wt% of hydrogen can be recharged. XRD and FTIR identified NaNH2 and Ca-N-H solid solution as dehydrogenation products. Concurrent with hydrogen absorption/desorption transformation between -NH and -NH2 units within solid solution was observed.