Thermal decomposition of B–N–H compounds investigated by using combined thermoanalytical methods

The thermal decomposition of borazane BH3NH3 in the temperature range up to 500 K has been studied by differential scanning calorimetry (DSC) and thermogravimetry (TG) combined with the FTIR spectroscopic and mass spectrometric analysis of the gas phase. Above 340 K borazane is decomposed in stages as the temperature is increased. The exothermic decomposition is accompanied by the release of approximately 2.2 mol H2/mol BH3NH3. This corresponds to a remarkable hydrogen storage density of 14.3 mass% related to the mass of borazane. In the gas phase above the solid decomposition residue monomeric aminoborane (BH2NH2), borazine (BHNH)3, which is the boron–nitrogen analog of benzene, and traces of diborane B2H6 were found beside hydrogen. The release of significant quantities of borazine was observed only at temperatures above 400 K.