Complexation-Assisted Synthesis of Hierarchical Fe-ZSM-5 Nanospheres with Stabilized Framework Fe2+ for Enhanced Fenton-like Degradation of Chlorobenzene

A novel Fe-doped ZSM-5 nanosphere catalyst was synthesized via a complex-assisted dynamic two-stage hydrothermal method using Na2EDTA as a chelating agent, followed by calcination under an inert atmosphere. The resulting material (Fe-ZSM-5EDTA-Ar) featured a hierarchical spherical architecture assembled from nanorods, possessing a high surface area (up to 511 m2/g), hierarchical porosity, and uniform dispersion of Fe species within the zeolite framework. Structural and spectroscopic analyses confirmed the successful isomorphous substitution of Fe2+/Fe3+ with a high proportion into the framework of ZSM-5, which concurrently enhanced structural stability and effectively suppressed iron leaching. Fe-ZSM-5EDTA-Ar demonstrated exceptional efficacy in the heterogeneous Fenton degradation of chlorobenzene (CB) employing H2O2 as the oxidant. This catalyst uniquely integrated high adsorption affinity with outstanding catalytic activity, resulting in complete dechlorination elimination of the target pollutant under optimized reaction conditions. Quenching experiments and electron paramagnetic resonance (EPR) collectively demonstrated that hydroxyl radicals were the dominant reactive oxygen species, driving the degradation process. Furthermore, Fe-ZSM-5EDTA-Ar also exhibited excellent recyclability in multiple cycles with negligible activity and iron loss. This work provides a robust synthesis strategy for designing stable and efficient zeolite-based Fenton catalysts for the remediation of chlorinated organic wastewater.