Synergistic Electrocatalytic N2 Reduction over Asymmetric Heteronuclear Dual Ru‐Fe Sites

A heteronuclear Ru‐Fe dual atom catalyst with asymmetryic coordination environment anchored on N,S‐codoped Ti3C2Tx nanosheet is reported. The asymmetric dual Ru‐Fe sites breaks the scaling relationship and synergistically improve eNRR efficiency. Abstract The scaling relationship limit poses a significant challenge in single‐atom catalysts (SACs) for reactions involving multi‐intermediate interactions, such as the electrocatalytic nitrogen reduction reaction (eNRR) for ammonia synthesis. To overcome this limitation, a heteronuclear dual Ru‐Fe sites on N,S‐codoped Ti3C2Tx nanosheet (referred to as Fe1‐N^S‐Ru1/Ti3C2Tx) with precisely designed asymmetric coordination for eNRR is developed. Advanced characterizations verify the unique asymmetric coordination structure where Ru and Fe atoms are individually coordinated to N and S atoms, respectively, with the two metal centers interconnected via bridging N and S atoms. This catalyst achieves remarkable eNRR performance with an NH3 yield rate of 32.8 µg h−1 mg−1cat at −0.55 V and 47.1% Faradaic efficiency at −0.25 V, surpassing its homonuclear analogues by 3.2‐ and 2.3‐fold in activity and ≈3.0‐fold in selectivity. Experimental and theoretical studies reveal a synergistic mechanism, in which Ru sites effectively dissociate H2O to supply protons while the adjacent Fe sites selectively activate N2, effectively decoupling proton supply from N2 activation but also benefiting the formation of key intermediate *NNH. Additionally, the electronic interaction between Ru and Fe sites also lowers the energy barrier of the rate‐determining step, thereby significantly enhancing catalytic activity and selectivity. A heteronuclear Ru-Fe dual atom catalyst with asymmetryic coordination environment anchored on N,S-codoped Ti 3 C 2 T x nanosheet is reported. The asymmetric dual Ru-Fe sites breaks the scaling relationship and synergistically improve eNRR efficiency. Abstract The scaling relationship limit poses a significant challenge in single-atom catalysts (SACs) for reactions involving multi-intermediate interactions, such as the electrocatalytic nitrogen reduction reaction (eNRR) for ammonia synthesis. To overcome this limitation, a heteronuclear dual Ru-Fe sites on N,S-codoped Ti 3 C 2 T x nanosheet (referred to as Fe 1 -N^S-Ru 1 /Ti 3 C 2 T x ) with precisely designed asymmetric coordination for eNRR is developed. Advanced characterizations verify the unique asymmetric coordination structure where Ru and Fe atoms are individually coordinated to N and S atoms, respectively, with the two metal centers interconnected via bridging N and S atoms. This catalyst achieves remarkable eNRR performance with an NH 3 yield rate of 32.8 µg h −1 mg −1 cat at −0.55 V and 47.1% Faradaic efficiency at −0.25 V, surpassing its homonuclear analogues by 3.2- and 2.3-fold in activity and ≈3.0-fold in selectivity. Experimental and theoretical studies reveal a synergistic mechanism, in which Ru sites effectively dissociate H 2 O to supply protons while the adjacent Fe sites selectively activate N 2, effectively decoupling proton supply from N 2 activation but also benefiting the formation of key intermediate * NNH. Additionally, the electronic interaction between Ru and Fe sites also lowers the energy barrier of the rate-determining step, thereby significantly enhancing catalytic activity and selectivity. Advanced Science, Volume 12, Issue 48, December 29, 2025.