Reconstructing the Linear Relations by Designing Bi-Atom Sites on NbS2 for the Efficient Nitrogen Reduction Reaction

Abstract

Tremendous enthusiasm for bi-atom catalysts (BACs) for the nitrogen reduction reaction (NRR) has been aroused due to the insufficient activation of N2 in single-atom catalysts (SACs). Herein, using density functional theory (DFT) calculations, the catalytic activities toward NRR of the NbS2-based SACs and BACs have been investigated. Our results reveal that there are typical volcano relationships between catalytic activities (limiting potentials) and the adsorption free energies of NNH* (∆G(NNH)*) on SACs, but the peak limiting potential is only −0.57 V. Interestingly, this volcano relationship can be reconstructed by supporting bi-atoms sites on NbS2, in which ∆G(NH2)* can serve as the descriptor to predict the catalytic performance of BACs. Most importantly, the optimal limiting potential of Mn2 BAC can reach a significant −0.26 V via an enzymatic pathway. These results compare catalytic activities between SACs and BACs and provide a theoretical basis for exploring novel, highly efficient electrocatalysts for NRR.