Single-Atom Anchored g-C(3)N(4) Monolayer as Efficient Catalysts for Nitrogen Reduction Reaction

Electrochemical N(2) reduction reaction (NRR) is a promising approach for NH(3) production under mild conditions. Herein, the catalytic performance of 3d transition metal (TM) atoms anchored on s-triazine-based g-C(3)N(4) (TM@g-C(3)N(4)) in NRR is systematically investigated by density functional theory (DFT) calculations. Among these TM@g-C(3)N(4) systems, the V@g-C(3)N(4), Cr@g-C(3)N(4), Mn@g-C(3)N(4), Fe@g-C(3)N(4), and Co@g-C(3)N(4) monolayers have lower ΔG(*NNH) values, especially the V@g-C(3)N(4) monolayer has the lowest limiting potential of −0.60 V and the corresponding limiting-potential steps are [Formula: see text] for both alternating and distal mechanisms. For V@g-C(3)N(4), the transferred charge and spin moment contributed by the anchored V atom activate N(2) molecule. The metal conductivity of V@g-C(3)N(4) provides an effective guarantee for charge transfer between adsorbates and V atom during N(2) reduction reaction. After N(2) adsorption, the p-d orbital hybridization of *N(2) and V atoms can provide or receive electrons for the intermediate products, which makes the reduction process follow acceptance-donation mechanism. The results provide an important reference to design high efficiency single atom catalysts (SACs) for N(2) reduction.