Self-supported zeolite fibers with multiscale porosity boosting mass transfer and stability for environmental...

Hierarchically porous catalysts with well-organized active sites offer new opportunities for accelerating pollutant degradation in aqueous environments. However, diffusion limitations and catalyst poisoning often create a lab-to-field performance gap. Here we developed a self-supported, hierarchically porous zeolite fiber catalyst (Fe-HZF) via solid transformation, which features interconnected micro-meso-macro pores and well-distributed active sites, and compared it against a substrate-supported zeolite fiber (Fe-SZF). Herein, response surface methodology (RSM) optimization achieved ∼99 % methylene blue removal under optimal conditions, with Fe-HZF exhibiting a > 10-fold higher kinetic constant than Fe-SZF (k = 0.0639 vs. 0.00527 t^-1·min^-1) and an ultralow activation energy (3.25 kJ mol^-1), surpassing literature reported catalysts on both kinetic and thermodynamic metrics. Molecular dynamics simulations revealed nearly doubled pollutant diffusivity (2.864 × 10^-8 vs. 1.595 × 10^-8 m² s^-1) and reduced adsorption energy (-139 vs. -557 kcal mol^-1) of the pollutant and stronger reactive oxygen species generation within Fe-HZF compared to Fe-SZF. Importantly, Fe-HZF maintained appreciable degradation of tetracycline in a representative natural-water matrix. Moreoever, cycling tests and post-reaction characterization suggested that the decrease of performance mainly involved carbonaceous deposition, active-species evolution, and changes in surface oxygen functionalities. Collectively, this work establishes self-supported, multiscale porous zeolite architectures as a highly effective platform for rapid advanced oxidation, while providing mechanistic insights into poisoning-induced deactivation that inform the design of more durable catalysts for water purification.