Heteronuclear transition metal decorated C2N monolayer: Promising catalysts for nitrogen reduction reactions

Electrochemical nitrogen reduction reaction offers a sustainable alternative to the energy-intensive Haber-Bosch for Ammonia (NH 3 ) synthesis. The electrocatalytic performance of heteronuclear double transition metal catalysts (TM 2 @C 2 N, TM = Fe, Co, Ni, Cu, and Mo) anchored on C 2 N monolayer is investigated using the first-principles calculations. The binding energy calculations confirm that all structures are thermodynamically stable except for the Ni–Cu@C 2 N catalyst. A selectivity test between NRR and the competing hydrogen evolution reaction (HER) identifies five catalysts that exhibit NRR selectivity. The Co–Mo@C 2 N and Ni–Mo@C 2 N catalysts stand out, achieving 100 % Faradaic efficiency, making them highly promising candidates for efficient NH 3 production. Our calculated reaction pathways identify potential-determining steps for alternating and distal mechanisms. Co–Mo@C 2 N demonstrates a limiting potential of −0.57 eV compared to −0.77 eV in the case of Ni–Mo@C 2 N. The synergistic role of Co and Mo atoms in Co–Mo@C 2 N, particularly during the distal mechanism, highlights the advantage of heteronuclear active sites in enabling efficient electrocatalytic N 2 conversion to NH 3 . Our ab-initio molecular dynamics simulations confirm the thermal stability of selected catalysts under operating conditions. Our findings highlight the crucial role of heteronuclear sites in improving catalytic efficiency and selectivity. The robust structural stability, efficient charge transfer, and favorable reaction energetics position these Co–Mo@C 2 N and Ni–Mo@C 2 N catalysts in the list of highly promising catalysts for sustainable ammonia production through the electrochemical NRR. • Co–Mo@C 2 N and Ni–Mo@C 2 N show excellent electrochemical nitrogen reduction activity. • Achieve 100 % Faradaic efficiency, suppressing the competing HER. • Co–Mo@C 2 N has a low limiting potential of − 0.57 eV , outperforming Ni–Mo@C 2 N (− 0.77 eV ). • Strong charge transfer from Mo weakens the N N bond, boosting catalytic performance. • Bimetallic catalysts (Mo with Co/Ni) balance efficiency, stability, and affordability.