Three-dimensional Hollow Catalysts with Edge-Defective Fe-Nx Sites and Enhanced Peroxymonosulfate Activation Performance: Preparation, Applications, and Mechanism

•Fe-N-C catalyst with a three-dimensional porous structure and excellent catalytic performance was synthesized.•The accessibility of internal active sites was enhanced by melamine-assisted pyrolysis.•Non radical pathway dominated by singlet oxygen played a key role in Fe-N-C/PMS system.•Pyrrole N can adsorb pollutants onto the catalyst surface, thereby shortening the mass transfer distance between pollutants and reactive oxygen species.•The degradation pathway and mechanism of BPAF has been studied based on LC-MS analysis.