Detailed structural evolution of lithium hydride under flowing ammonia and hydrogen by in situ neutron diffraction

There has been tremendous interest in metal hydride chemistry over the last two to three decades, with the emphasis on the use of lightweight hydrides as potential high-capacity hydrogen stores. One of the most promising lightweight hydrogen store such as LiH has gathered great attention because of its chemical simplicity, high thermal stability, and high gravimetric content of 8.1% mass, and it involves hydrogen cycling between lithium imide and lithium amide. Under gas flowing conditions, we expect to form non-stoichiometric phases of hydride-nitride in the form of Li1+xNH2−x. we propose for the first time a detailed in situ neutron diffraction study of the ammonolysis reaction (hydrogen generation) of lithium hydride using gaseous ammonia and hydrogenation reaction (ammonia synthesis) under hydrogen flow. We expect the coexistence of the hydride-amide phases and their impact on the Hδ+-Hδ- exchange mechanism involved will be of interest to a broader hydrogen generation, storage and ammonia synthesis communities. We ask for 3 days on Polaris to study four separate samples under flowing gas conditions.