Phosphorus vacancy-rich FeP@Al₂O₃ catalyze hydrogen peroxide decomposition for wastewater purification: Catalytic mechanism and performance evaluation

In this work, phosphorus vacancies-rich (PV-rich) FeP@Al2O3 spheres with 4-6 mm were prepared by FeSO4 as initial material and porous Al2O3 as carrier. The formation of FeP@Al2O3 experienced oxidation, polymerization, load, transformation and phosphorization processes. PV-rich FeP@Al2O3 catalyst not only overcame the short-comings of powder catalyst, such as easy loss and difficult recovery after reaction, but also exhibited high catalytic activity for the activation of H2O2 and the degradation of antibiotics and dyes. The high removal efficiencies were remained over 9 cycles. Mechanism research indicated that both Fe and P could activate H2O2 to generate (OH)-O-center dot. Experimental and density functional theory calculation results showed that the formation of PVs allowed more electrons to be transferred to O-2 to produce O-2(center dot-). The (OH)-O-center dot and O-2(center dot-) can effectively degrade pollutants in a batch reactor and a continuous degradation reactor. This study provided an essential reference for the rational design of high-performance Fenton-like catalyst to degrade organic wastewaters.