title: Hydrazine borane-induced destabilization of ammonia borane, and vice versa.
abstract: In the field of solid-state chemical hydrogen storage, ammonia borane NH3BH3 has been widely studied while hydrazine borane N2H4BH3 can be considered as a "novel" material. In the present work, we investigated the behaviour of these boranes when mixed together in a mole ratio of 1:1. Hydrazine borane and ammonia borane destabilize each other. Though stable at 20-25 °C, the mixture melts at ∼ 30 °C and then undergoes significant decomposition, with desorption of hydrogen H2 and hydrazine N2H4 from 67 °C. This is explained by the fact that the presence of hydrazine borane disrupts the H(δ+)⋯ H(δ-) network of ammonia borane, and vice versa; the mixture is then much less stable than the pristine boranes. The mixture can nevertheless be stabilized (by heat- or vacuum-treatment and thus extraction of evolving hydrogen and hydrazine), making the as-obtained solid a potential chemical hydrogen storage material. Over the range 25-300 °C, it is able to release ca. 11.4 wt% of almost pure H2. Furthermore forms boron nitride as the solid residue, at temperatures as low as 300 °C.
authors: IEM (Institut Europeen des Membranes), UMR 5635 (CNRS-ENSCM-UM2), Universite Montpellier 2, Place E. Bataillon, F-34095 Montpellier, France.
authors: Jean-Fabien
authors: JF
authors: Petit
authors: IEM (Institut Europeen des Membranes), UMR 5635 (CNRS-ENSCM-UM2), Universite Montpellier 2, Place E. Bataillon, F-34095 Montpellier, France.
authors: Georges
authors: G
authors: Moussa
authors: IEM (Institut Europeen des Membranes), UMR 5635 (CNRS-ENSCM-UM2), Universite Montpellier 2, Place E. Bataillon, F-34095 Montpellier, France. Electronic address: umit.demirci@um2.fr.
authors: Umit B
authors: UB
authors: Demirci
authors: Université Lyon 1, CNRS, UMR 5615, Laboratoire des Multimatériaux et Interfaces, 43 boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France.
authors: François
authors: F
authors: Toche
authors: Université Lyon 1, CNRS, UMR 5615, Laboratoire des Multimatériaux et Interfaces, 43 boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France.
authors: Rodica
authors: R
authors: Chiriac
authors: IEM (Institut Europeen des Membranes), UMR 5635 (CNRS-ENSCM-UM2), Universite Montpellier 2, Place E. Bataillon, F-34095 Montpellier, France.
authors: Philippe
authors: P
authors: Miele
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D008401:Gas Chromatography-Mass Spectrometry; D006859:Hydrogen / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D001896:Boron Compounds; D006859:Hydrogen
keywords: Ammonia borane; Boron nitride; Hydrazine; Hydrazine borane; Hydrogen; Polyborazylene