Lithium-nitrogen-hydrogen–transition metal composites for catalytic ammonia cracking: in situ neutron powder diffraction

Metal-nitrogen-hydrogen materials are an emerging family of affordable, earth-abundant catalysts for ammonia cracking, a critical process towards enabling the use of ammonia in energy storage. Lithium imide has been shown to out-perform commercial ruthenium-based catalysts1, and its activity may be further enhanced through the addition of transition metals2, although uncertainty persists surrounding the nature of the active phase and the role of the transition metals. Understanding in these areas is critical to inform the future design of these catalysts and thereby enable the wider use of ammonia as a zero-carbon energy store.
We request 4 days on POLARIS to conduct an in situ structural investigation on three composite ammonia decomposition catalysts: lithium imide–Cr, –Mn, and –Fe. We wish to probe the active form of the catalysts, determining whether the imide and transition metal species form an active ternary nitride or if transition metals affect the interconversion between lithium imide and amide.