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

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 C9N4 substrate (Mo@C9N4) to form an efficient single-atom catalyst (SAC) is proposed for the conversion of N-2 to NH3. By employing density functional theory (DFT) calculations, we demonstrated that gas phase N-2 can be sufficiently activated and efficiently reduced to NH3 on the surface of Mo@C9N4. 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@C9N4 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. (C) 2020 Published by ELSEVIER B.V. and Science Press on behalf of Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences.