Kinetic and thermodynamic investigation of hydrogen release from ethane 1,2-di-amineborane

Abstract

The thermodynamics and kinetics of hydrogen (H₂) release from ethane 1,2-di-amineborane (EDAB, BH₃NH₂CH₂CH₂NH₂BH₃) were measured using Calvet and differential scanning calorimetry (DSC), pressure-composition isotherms, and volumetric gas-burette experiments. The results presented here indicate that EDAB releases ∼ 10 wt.% H₂ at temperatures ranging from 100 °C to 200 °C in two moderately exothermic steps, approximately −10 ± 1 kJ mol⁻¹ H₂ and −3.8 ± 1 kJ mol⁻¹ H₂. Isothermal kinetic analysis shows that EDAB is more stable than ammonia borane (AB) at temperatures lower than 100 °C; however, the rates of hydrogen release are faster for EDAB than for AB at temperatures higher than 120 °C. In addition, no volatile impurities in the H₂ released by EDAB were detected by mass spectrometry upon heating with 1 °C min⁻¹ to 200 °C in a calorimeter.