Highly Dispersed Mn/Si-N/C Dual-Lewis Acid Sites for Enhanced Reactive Oxygen Species Generation and Efficient Water Purification

Heterogeneous catalytic ozonation has emerged as an effective approach for wastewater treatment, with its core challenge lying in the effective enhancement of reactive oxygen species (ROS) generation. This work proposed to synthesize a highly dispersed Mn/Si-N/C dual-Lewis acid sites catalyst by carrier surface modification. The successful preparation of a Mn/Si-N/C@Al2O3 catalyst was verified by a series of characterizations, including XRD, FT-IR, and XPS, and the introduction of Si-N/C significantly increased the Lewis acid site content (about 66%), which was positively correlated with the yields of ROS. Furthermore, the dual-Lewis acid sites improved the affinity for ozone and realized the enhanced generation of ROS (the yields increased by 13–60%). The chemical oxygen demand (COD) removal rate for actual wastewater reached more than 61%, and it remained stable after reuse of the catalyst 5 times. This work provides new ideas for the synthesis of efficient catalysts and enhanced generation of ROS in advanced oxidation processes.