Single-atomic Fe−N3C sites with optimized oxophilicity for high-efficiency periodate activation toward pollutant abatement via preferential 1O2

Single-atom catalysts (SACs) are an effective strategy for maximizing the efficiency and reducing the costs of advanced oxidation processes (AOPs). Herein, a novel SAC with Fe−N 3 C sites was synthesized for emerging periodate (PI)-based AOPs. The optimized catalyst demonstrates superior performance, achieving 100 % removal of diclofenac (DCF) within 20 min via predominant singlet oxygen ( 1 O 2 ). Compared to the Fe−N 4 configuration, the Fe−N 3 C site enables an unprecedented 152.9-fold increase in the pollutant degradation rate, surpassing most reported catalysts. Density functional theory (DFT) calculations reveal that the Fe−N 3 C sites reduce the oxophilicity of the Fe centers, thereby lowering the energy barrier for 1 O 2 desorption and promoting its preferential generation. The DCF degradation pathway was further elucidated by Fukui constants. Furthermore, the Fe−N 3 C/PI system exhibits excellent stability with negligible leaching of Fe ions and strong resistance to common wastewater components. This work provides new insights into the design of efficient SACs and the construction of PI-based AOPs for water decontamination.