Flexible Iron Clusters Promoting Ammonia Synthesis: A Density Functional Theory Prediction

In recent years, significant research has been conducted on supported clusters due to their high dispersion, atomic efficiency, and unsaturated coordination, particularly in ammonia synthesis. This study investigates the catalytic performance of flexible iron clusters embedded in two-dimensional carbon–nitrogen materials for ammonia synthesis. Using density functional theory and ab initio molecular dynamics simulations, we demonstrate that the structural flexibility of these clusters significantly enhances their catalytic activity. The flexibility coefficient, derived from the full width at half maximum of the Fe–Fe radial distribution function, is introduced as a novel descriptor for N₂ bond cleavage. Our findings reveal that flexible Fe clusters adaptively modify their structures during the reaction process, lowering energy barriers for N₂ activation and subsequent hydrogenation. This study opens new avenues for designing advanced catalytic systems based on structural flexibility to meet the growing demand for sustainable and energy-efficient ammonia production.