Computational investigation of MnIr and FeIr electrocatalyst for nitrogen reduction reaction

Abstract

NH3 is not only an important component of agricultural and industrial production, but also an extremely promising energy carrier and storage intermediate. Currently, the Haber‐Bosch process used in industry for NH3 production has shortcomings such as high energy consumption and low output. The electrocatalytic nitrogen reduction reaction (NRR) can improve the route and conditions of NH3 synthesis through high‐efficient electrocatalyst, and realize the production mode of high efficiency and low energy consumption. Therefore, the design and synthesis of the NRR electrocatalysts with high catalytic performance are very important. Here, the first principles calculation based on density functional theory was used to form alloy catalysts by using Mn and Fe atoms instead of nine Ir atoms on the surface of Ir(100), and the electrocatalytic performance of the NRR was systematically studied. The results showed that N2 could be stably adsorbed on Mn9@Ir(100) and Fe9@Ir(100) in the side‐on configuration. The possible reaction pathways were analyzed and discussed, and the enzymatic pathway was determined to be the best. Through the simulation of the entire NRR process, it was found that the limit potential was only −0.659 and −0.647 V for Mn9@Ir(100) and Fe9@Ir(100). In addition, the electronic properties of Mn9@Ir(100) and Fe9@Ir(100) were analyzed utilizing charge density difference and density of states, and the reasons for their high activity were obtained. We hope this work can not only reduce the number of noble metals and develop highly active catalysts, but also provide theoretical support and guidance for the catalytic mechanism of alloy electrocatalysts.