# Nature of the Lithium Amide–Imide Catalyst System under Ammonia Decomposition Conditions

## TL;DR

This study reveals how a lithium amide-imide catalyst changes during ammonia decomposition, showing phase transitions and structural changes at high temperatures.

## Contribution

The paper identifies a phase transition and formation of nitride hydride groups in the catalyst under ammonia decomposition conditions.

## Key findings

- The catalyst transitions from a molten amide-rich state to a solid imide-rich state above 460 °C.
- Gas release events indicate a phase change rather than a smooth amide-to-imide shift.
- Nitride hydride groups form at higher temperatures within the catalyst structure.

## Abstract

The varying stoichiometry of the lithium amide–imide
ammonia
decomposition catalyst under working conditions was ascertained by
calculating the gas release events in the ammonia decomposition experiments.
Rather than varying smoothly between amide and imide, the gas releases
showed evidence of a molten state with a majority of amide stoichiometry
before converting at temperatures above 460 °C to a solid with
a majority of imide stoichiometry. At higher temperatures, there was
indirect evidence of nitride hydride groups being formed within the
catalyst structure.