Defective hierarchical porous Ce-UiO-66 excites phosphotungstic acid for superior low-temperature oxidative desulfurization

Metal-organic frameworks (MOFs) as host-guest catalyst in oxidative desulfurization (ODS) face challenges due to limited access to active sites through their microporosity. Herein, hierarchical porous Ce-UiO-66 (HCU) was synthesized through a templating method in an aqueous environment to enhance host accessibility; phosphotungstic acid (PW) was uniformly loaded within the mesopores of HCU via post-impregnation; Ce sites were exposed by selective removing the coordinated acetate from the HCU with the acid post-treatment, these synergistically optimized the catalytic potential of the composite. The resulting HCU@5PW-H demonstrates outstanding desulfurization performance (1000 ppm sulfur removal) within 16 minutes under mild conditions (40 °C, O/S molar ratio = 5) and maintains high efficiency over at least eight cycles. The catalytic mechanism involves the decomposition of H 2 O 2 to reactive oxygen species (ROS) and the formation of W VI -peroxo intermediates that determine the ODS activity. This synergistic mechanism offers a promising strategy to enhance the oxidation potential of hierarchical porous MOF-based host-guest catalysts under mild conditions.