Enhancing Catalytic Properties of Iron- and Nitrogen-Doped Carbon for Nitrogen Reduction through Structural Distortion: A Density Functional Theory Study

Abstract

In this study, we have performed the first-principles density functional theory calculations to predict the influence of structural distortion on the catalytic properties of Fe, N codoped carbon (Fe–N–C) for the nitrogen reduction reaction (NRR). On both FeN4 and FeN3 sites embedded in a graphene layer, our results show that compressive strain not only enhances the NRR activity manifested by a positive change in NRR limiting potential, but also changes the favorable NRR pathway from a hybrid path to a distal one. The activity enhancement is attributed to the strong binding of NRR intermediate species, *NNH, on the strained active sites. Moreover, we predict that the NRR selectivity on both FeN4 and FeN3 sites is improved by the structural distortion induced by compressive strain. Hence, our computational results suggest that the degree of compressive strain in the graphene layer of Fe–N–C catalysts could be tuned to enhance their catalytic activity and selectivity for NRR.