A study of ammonia borane and its derivatives

Thesis

This thesis reports the investigation of molecular materials for hydrogen storage applications with a particular emphasis on alkali-metal amidoboranes. I have developed new routes for the synthesis of $alpha$-LiNH$_{2}$BH$_{3}$ and NaNH$_{2}$BH$_{3}$, and have studied their hydrogen storage properties by thermogravimetric analysis, variable temperature X-ray and neutron diffraction and inelastic neutron scattering. I report the synthesis and full structural characterization of two new materials, KNH$_{2}$BH$_{3}$ and $beta$-LiNH$_{2}$BH$_{3}$, and have performed initial studies on a tetragonal phase of a variant of LiNH$_{2}$BH$_{3}$ with a preliminary structure solution. I have also performed variable temperature neutron diffraction on ammonium borodeuteride, ND$_{4}$BD$_{4}$, and report the full structural characterisation of the three phases identified as a result of these measurements. Furthermore, variable temperature inelastic neutron scatting (INS) measurements were performed on ammonia borane, NH$_{3}$BH$_{3}$, and the results are discussed in terms of crystallographic phase changes.

Authors: Ryan, K

• Publication date: 2011
• DOI: 10.5287/ora-m8yjv2dyy
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: Oxford University, UK
• Language: English
• Keywords: hydrogen storage; ammonia borane; neutron scattering
• Subjects: Solid state chemistry; Chemistry & allied sciences; Chemical crystallography; Inorganic chemistry; Advanced materials; Crystallography; Hydrogen Storage