Boron chemistry for energy application

The present work is structured around boron-based materials expected to be used in the field of 'energy'. We especially worked on two types of materials. (i) With the first type, solid-state hydrogen storage was targeted. Hydrazine borane N₂H₄BH₃ was used as precursor of novel derivatives obtained by mechano-synthesis. We first made it react with lithium amide LiNH₂ to obtain LiN₂H₃BH₃.0.25NH₃. Then, we considered calcium hydride CaH₂; it reacted with N₂H₄BH₃ at 67° (after ball-milling) to form a new phase, calcium hydrazinidoborane of formula Ca(N₂H₃BH₃)₂. (ii) The second type of boron-based materials we investigated is about anionic poly-boranes. They are known to be stable in aqueous solution and accordingly could be used as anodic fuel of direct liquid-fed fuel cell. We aimed at synthesizing and fully characterizing two salts: sodium closo-decaborane Na₂B₁₀H₁₀ and sodium 1-oxa-nido-dodeca-borate NaB₁₁H₁₂O. Their potential for the aforementioned application was tested by cyclic voltammetry by using bulk electrodes of platinum, silver and gold. All of our results are presented, discussed in detail and put into perspective in the present thesis. (author)