How Does Structural Disorder Impact Heterogeneous Catalysts? The Case of Ammonia Decomposition on Non-Stoichiometric Lithium Imide

Among the many catalysts suggested for ammonia decomposition, Li2NH has been shown to be quite promising. In the recent past, we have performed extensive \textit{ab-initio}-quality simulations to explain the workings of this unusual catalyst. In the complex scenario that has emerged, surface dynamics and structural disorder enhanced by the interaction with the reacting ammonia molecules played a crucial role. Non-stoichiometric lithium imide Li(2-x)(NH2)x(NH)(1-x) has been reported to have better catalytic performances than pure lithium imide. Stimulated by these findings, we follow up our first study simulating the ammonia decomposition on such non-stoichiometric compound. We attribute the enhanced reactivity to the fact that the compositional disorder further enhances the fluctuations in the topmost layers of the catalyst, strengthening our dynamical picture of this catalytic process.