Lateral Asymmetric Fe‐Mn Dual‐Atomic Sites for Efficient Nitrate Reduction ^†

Comprehensive Summary The development of efficient electrocatalysts for the reduction of nitrate (NO 3 ‐ ) to ammonia (NH 3 ) offers a sustainable alternative to the energy‐intensive Haber–Bosch process, positioning this approach as a key focus in low‐carbon and environmental research. However, practical implementation of the nitrate reduction reaction (NO 3 ‐ RR) remains challenging due to the complexity of proton‐coupled electron transfer and the sluggish kinetics arising from diverse reaction intermediates. In this work, we present an asymmetric Fe/Mn diatomic catalyst anchored on a metal–organic framework (MOF)‐derived carbon skeleton, which exhibits outstanding catalytic performance for NH 3 synthesis, achieving a Faradaic efficiency of 98.7% at −0.4 V vs. RHE. Through combined in situ X‐ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations, we reveal that in the asymmetric Fe‐Mn/SNC structure, strong electronic coupling between Fe and Mn active sites, together with synergistic modulation by S and N atoms, effectively optimizes the electronic structure, enhances structural stability, and ensures optimal atomic dispersion. The proposed transverse coordination‐asymmetric heteronuclear diatomic cooperation mechanism provides a novel design strategy for advancing nitrate reduction and electrocatalytic ammonia synthesis.