A Readily Achieved Potentiostatic Method in Density Functional Theory Calculation for Improved Prediction of the Performance for Electrocatalytic Nitrogen Reduction Reaction

Accurate prediction of the catalytic performance of nitrogen reduction reaction catalysts based on density functional theory (DFT) calculation is of great significance for developing catalytic materials for nitrogen fixation. However, the applied electrode potential induced the fixation of Fermi level and solvation effect are commonly ignored in the current computational hydrogen electrode method, which leads to the large deviation between the calculation predicted limit potential and the experimentally measured limit potential. In this work, the simple external iteration method is proposed to simulate the Fermi level of the catalysts that are fixed by the applied electrode potential, along with the hybrid solvent model to describe the strong interaction, such as hydrogen bond, between the solvent molecules and the intermediates. This method allowed the theoretical and experimental limit potentials to be in good agreement, indicating the significant effect of the electrode potential and solvation in the DFT calculation. These results will guide the calculation-based prediction of other reaction systems in the field of electrocatalysis. The accuracy of overpotential prediction is greatly improved by means of the constant potential method combined with the hybrid solvent model.image

Automated summary

Accurate prediction of catalytic performance based on DFT calculation is crucial for nitrogen fixation. However, current computational methods ignore the effects of electrode potential and solvation, resulting in large deviations between predicted and measured potentials. This study proposes an external iteration method and a hybrid solvent model to account for these effects, achieving good agreement between theoretical and experimental potentials. These findings have important implications for prediction of other electrocatalytic systems.