Single‐Atom Bismuth Catalyst with Sulfur Modulation: Toward Efficient Electrochemical Ammonia Synthesis via NRR‐EGOR Integration

Exploring a nitrogen reduction reaction (NRR) technology utilizing single-atom electrocatalysts, our research aims to develop an environmentally benign and highly efficient approach for ammonia (NH₃) synthesis. A sulfur-doped single-atom bismuth-based nitride catalyst (S-BiNSPC) was synthesized via a molecular engineering strategy, and its structure and electrochemical NRR performance were thoroughly characterized. X-ray photoelectron spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS) analyses revealed that sulfur incorporation optimizes the electronic structure and local geometry of bismuth, significantly enhancing NRR activity. Experimental results demonstrated that S-BiNSPC exhibited excellent NRR performance in 0.1 m KOH electrolyte, achieving an ammonia yield of 77.71 µg.h^-1 mgcat^-1 and a Faraday efficiency (FE) of 37.03%. Density functional theory (DFT) calculations indicated that sulfur doping lowers the energy barrier for the initial hydrogenation step and optimizes the electronic structure for nitrogen activation. In a system where the NRR is coupled with the ethylene glycol oxidation reaction (EGOR), the reaction potential was reduced and the generation of high-value-added products was enabled. This research offers novel perspectives on the advancement of high-performance NRR catalysts and highlights their potential for practical implementation.