High Throughput Screening and Effective Optimization Strategy of WO₃-Supported Single-Atom Catalysts for Electrocatalytic Nitrogen Reduction Reaction

As the main method of industrial ammonia synthesis, the Haber–Bosch process has high energy consumption and will cause serious pollution to the environment, electrochemical ammonia synthesis provides an ideal strategy to solve this problem, however, the lack of highly active and selective catalysts limits its industrial application. To develop an efficient electrochemical nitrogen reduction (eNRR) catalyst, we designed and screened 38 WO3-supported single-atom catalysts (SACs) by density functional theory (DFT) calculations. Based on a four-step screening strategy, i.e., the stability of catalysts, nitrogen adsorption, catalytic activity, and selectivity, U/WO3 was screened out to have a low limit potential of −0.48 V when eNRR following the consecutive pathway. The electronic structure analysis shows that the effective activation of nitrogen by U/WO3 is due to the interaction that effectively moves the molecular orbitals of nitrogen to the low-energy region. Furthermore, we found the presence of oxygen vacancies on the WO3 substrate can effectively enhance the stability and catalytic activity of U/WO3 to NRR, in which the limiting potential of the distal path becomes −0.35 V, but it also makes the desorption of NH3 more difficult. This theoretical work provides a reasonable strategy for designing efficient eNRR catalysts under ambient conditions.