Coordination Engineering of Heteronuclear Fe-Mo Dual-Atom Catalyst for Promoted Electrocatalytic Nitrogen Fixation: A DFT Study.

Developing efficient nanostructured electrocatalysts for N reduction to NH under mild conditions remains a major challenge. The Fe-Mo cofactor serves as the archetypal active site in nitrogenase. Inspired by nitrogenase, we designed a series of heteronuclear dual-atom catalysts (DACs) labeled as FeMoN X (a=1, 2, 3; X=B, C, O, S) anchored on the pore of g-C N to probe the impact of coordination on FeMo-catalyzed nitrogen fixation. The stability, reaction paths, activity, and selectivity of 12 different FeMoN X DACs have been systematically studied using density functional theory. Of these, four DACs (FeMoN B , FeMoN O , FeMoN O , and FeMoN C ) displayed promising nitrogen reduction reaction (NRR) performance. Notably, FeMoN O stands out with an ultralow limiting potential of -0.11 V and high selectivity. Analysis of the density of states and charge/spin changes shows FeMoN O 's high activity arises from optimal N binding on Fe initially and synergy of the FeMo dimer enabling protonation in NRR. This work contributes to the advancement of rational design for efficient NRR catalysts by regulating atomic coordination environments.