The first principles study of the dual-atom catalyst based on g-C3N5 for efficient nitrogen fixation

Electrocatalytic nitrogen reduction reaction (NRR) for ammonia production has broad prospects because of its mild green reaction conditions. However, the available catalysts cannot meet the needs of industrial ammonia production due to low catalytic activity and poor selectivity. In our work, the dual-atom catalysts (DAC) supported by g-C3N5 with transition metals dual-atom were designed based on the first principles calculation. Based on the criteria of stability, catalytic activity, and the competitive landscape between NRR and hydrogen evolution reaction (HER), the Ni2/g-C3N5 stands out as the most promising candidate among 30 designed diatomic catalysts for NRR, exhibiting remarkable potential for this reaction. In fact, the Ni2/g-C3N5 possesses low limiting potential (-0.27 V) and its selectivity of NRR is nearly 100%. Importantly, by comprehensively considering the pivotal parameters of charge order, electronegativity, and d-band center, a dedicated descriptive descriptor has been formulated. This results not only profoundly uncovers the intrinsic origins of catalytic activity in the NRR but also significantly expedites the screening process for highly efficient catalysts. Our work not only accelerates the search for an NRR catalyst with high activity but also provides theoretical guidance for subsequent experiments on DACs.