Enhanced activation of peroxymonosulfate by Fe/N co-doped ordered mesoporous carbon with dual active sites for efficient removal of m-cresol

Abstract

The novel Fe-N co-doped ordered mesoporous carbon with high catalytic activity in m-cresol removal was prepared by urea-assisted impregnation and simple pyrolysis method. During the preparation of the Fe-NC catalyst, the complexation of N elements in urea could anchor Fe, and the formation of C3N4 during urea pyrolysis could also prevent migration and aggregation of Fe species, which jointly improve the dispersion and stability of Fe. The FeN4 sites and highly dispersed Fe nanoparticles synergistically trigger the dual-site peroxymonosulfate (PMS) activation for highly efficient m-cresol degradation, while the ordered mesoporous structure of the catalyst could improve the mass transfer rate of the catalytic process, which together promote catalytic degradation of m-cresol by PMS activation. Reactive oxygen species (ROS) analytic experiments demonstrate that the system degrades m-cresol by free radical pathway mainly based on SO4-· and ·OH, and partially based on ·OH as the active components, and a possible PMS activation mechanism by 5Fe-50 for m-cresol degradation was proposed. This study can provide theoretical guidance for the preparation of efficient and stable catalysts for the degradation of organic pollutants by activated PMS.