Computational Screening and Mechanistic Study of Transition Metal Single Atoms on WS ₂ for Electrocatalytic Nitrogen Reduction to Ammonia

NH₃ is a crucial substance extensively utilized in various fields, including chemical engineering, agriculture, and medicine. However, the conventional NH₃ synthesis method known as the Haber-Bosch process faces significant challenges such as severe reaction conditions, high energy consumption, and substantial CO₂ emissions. Consequently, employing electrochemical technology to convert atmospheric nitrogen sources and water into NH₃ using renewable energy has emerged as a method that offers both environmental benefits and economic value. Nevertheless, the electrocatalytic nitrogen reduction reaction (NRR) process is confronted with problems of low activity and poor selectivity. Therefore, there is an urgent need to identify electrocatalysts with excellent stability, catalytic activity, and selectivity. Based on density functional theory calculations, we designed a series of transition metal (TM = Ti-Cu; Zr-Ag; Hf-Au) atom-doped WS₂ formation in TM@WS₂ catalysts for the NRR process. Through a four-step screening strategy, V@WS₂, Os@WS₂, and Ir@WS₂ were identified as having outstanding activity and selectivity toward NRR. Furthermore, by analyzing the electronic structures, we revealed the source of the catalytic activity while exploring the intrinsic relationship between the electronic structure and catalytic performance. This research provides a certain degree of insight and theoretical basis for optimizing electrochemical NH₃ synthesis catalysts.