Computational evaluation of FeMo heteroatom coeffect induced high electroreduction activity of N2-to-NH3

Fe-Mo system are recognized as the most successful nitrogenases system towards the synthesis of ammonia. At the same time, Fe or Mo plays a key role in nitrogenase enzymes together with the most common catalyst for nitrogen reduction reaction (NRR). Herein, we designed and explored NRR catalysts of bimetallic Fe-Mo atoms incorporating on three 2D materials, including graphdiyne (GD), Nitrogen atoms substituted graphene (G-N-6) and C2N, by means of density functional theory. Fe-Mo atoms supported on C2N is calculated to the most promising one owing to its lowest limiting potential (-0.17 V) and excellent selectivity against hydrogen evolution reaction. The superior performance of FeMo dual-atom NRR catalysts has also been verified by comparing to individual Fe or Mo involved catalysts on account of synergistic effects. Besides, the high NRR activity of FeMo@C2N could be ascribed to the high localized electronic states of 3d/4d and 2p orbitals near the Fermi level, providing the Fe-Mo active sites with optimal electronic state. Our studies would further inspire some experimental and theoretical researchers to find out the efficient catalysts with high activity for the synthesis of ammonia at room temperature.

Automated summary

Fe-Mo system is considered the most successful nitrogenase system in synthesizing ammonia, with Fe or Mo playing key roles in nitrogen reduction reaction (NRR). By incorporating Fe-Mo atoms on 2D materials, Fe-Mo supported on C2N is found to be the most promising NRR catalyst, showing superior performance and excellent selectivity. The high NRR activity of FeMo@C2N is attributed to the high localized electronic states near the Fermi level, providing optimal electronic state for Fe-Mo active sites.