Screening Janus‐2H‐WSSe with Adsorbed Transition Metals as Efficient Catalyst for Nitrogen Reduction Reaction

Electrocatalytic nitrogen reduction reaction (NRR) provides a promising strategy for effective nitrogen fixation under mild conditions. Herein, structural stability and NRR catalytic activity of 29 transition metal (TM, Sc‐Hg) atoms adsorbed Janus 2H‐WSSe monolayers are studied using the first‐principles calculations. Six screened TM@S/Se‐WSSe (TM = Os, Re) and TM@Se‐WSSe (TM = Ir, Mo) systems are considered promising single‐atom catalysts (SACs) due to low limiting potential (−0.36 to −0.73 V) and high Faradaic efficiency (FE > 90.61%). High catalytic activity arises from the donation and back‐donation mechanisms between the empty/unoccupied TM‐ d orbitals and the bonding/antibonding N 2 ‐ p orbitals, which significantly promote the activation of N 2 and the charge transfer in the subsequent hydrogenation reactions. In addition, the catalytic activity trend of the screened TM@WSSe systems is further analyzed by four descriptors (Δ G *NNH , Δ G *NH2 , Δ G *N , and φ ). The high activity can be achieved by individually tuning Δ G *NH2 or Δ G *NNH . Meanwhile, the TM@WSSe with Δ G *N = −1.38 eV and φ = 6 exhibits the best catalytic activity. The results provide insights into designing efficient nitrogen fixation electrocatalysts.