Regeneration of Ammonia Borane Spent Fuel by Direct Reaction with Hydrazine and Liquid Ammonia.

Polyborazylene which is formed by removal of more than two equivalents of H2 per molecule from NH3·BH3 is converted back to ammonia borane nearly quantitatively by a 24-hour treatment with N2H4 in liquid NH3 at 40 °C (sealed pressure vessel).