Theoretical Study on B‐doped FeN4 Catalyst for Potential‐Dependent Oxygen Reduction Reaction

Abstract

AbstractElectrochemical reactions mostly take place at a constant potential, but traditional DFT calculations operate at a neutral charge state. In order to really model experimental conditions, we developed a fixed‐potential simulation framework via the iterated optimization and self‐consistence of the required Fermi level. The B‐doped graphene‐based FeN4 sites for oxygen reduction reaction were chosen as the model to evaluate the accuracy of the fixed‐potential simulation. The results demonstrate that *OH hydrogenation gets facile while O2 adsorption or hydrogenation becomes thermodynamically unfavorable due to the lower d‐band center of Fe atoms in the constant potential state than the neutral charge state. The onset potential of ORR over B‐doped FeN4 by performing potential‐dependent simulations agree well with experimental findings. This work indicates that the fixed‐potential simulation can provide a reasonable and accurate description on electrochemical reactions.