Sodium Hydrazinidoborane: A Chemical Hydrogen‐Storage Material

Abstract Herein, we present the successful synthesis and full characterization (by 11 B magic‐angle‐spinning nuclear magnetic resonance spectroscopy, infrared spectroscopy, powder X‐ray diffraction) of sodium hydrazinidoborane (NaN 2 H 3 BH 3 , with a hydrogen content of 8.85 wt %), a new material for chemical hydrogen storage. Using lab‐prepared pure hydrazine borane (N 2 H 4 BH 3 ) and commercial sodium hydride as precursors, sodium hydrazinidoborane was synthesized by ball‐milling at low temperature (−30 °C) under an argon atmosphere. Its thermal stability was assessed by thermogravimetric analysis and differential scanning calorimetry. It was found that under heating sodium hydrazinidoborane starts to liberate hydrogen below 60 °C. Within the range of 60–150 °C, the overall mass loss is as high as 7.6 wt %. Relative to the parent N 2 H 4 BH 3 , sodium hydrazinidoborane shows improved dehydrogenation properties, further confirmed by dehydrogenation experiments under prolonged heating at constant temperatures of 80, 90, 95, 100, and 110 °C. Hence, sodium hydrazinidoborane appears to be more suitable for chemical hydrogen storage than N 2 H 4 BH 3 .