Anchoring Mo on C9N4 monolayers as an efficient single atom catalyst for nitrogen fixation

Abstract

This work reports a novel Mo-based SAC catalyst (Mo@C 9 N 4 ), which exhibits excellent activity and selectivity toward electrochemical nitrogen reduction reaction with favorable limiting potential of 0.40 V. Electrochemical nitrogen fixation via a convenient and sustainable manner, exhibits an intriguing prospect for ammonia generation under ambient conditions. Currently, the design and development of high-efficiency and low-cost electrocatalysts remains the major challenge confronting nitrogen reduction reaction (NRR). Herein, anchoring the single Mo atom on the C 9 N 4 substrate (Mo@C 9 N 4 ) to form an efficient single-atom catalyst (SAC) is proposed for the conversion of N 2 to NH 3 . By employing density functional theory (DFT) calculations, we demonstrated that gas phase N 2 can be sufficiently activated and efficiently reduced to NH 3 on the surface of Mo@C 9 N 4 . Meanwhile, we found that the NRR dominantly occurred on the Mo center via a preferred distal pathway with favorable limiting potential of 0.40 V. Importantly, the as-established Mo@C 9 N 4 catalyst exhibits an outstanding structural stability and good selectivity toward NRR. These findings provide a promising platform for designing Mo-based SACs for electrochemical N 2 fixation.