Post-synthetic acid treatment of aqueous synthesized bimetallic Ce/Zr MOF-801 enables efficient oxidative desulfurization of model fuels

Host-guest catalysts are promising for tailored applications but require innovative synthesis strategies. Herein, we report the first ambient aqueous-phase synthesis of bimetallic Ce/Zr MOF-801, followed by acid post-treatment. Utilizing defect engineering, Ce species are preferentially exposed within the robust Zr-MOF-801 substrate. This structural modification substantially enhances the host–guest catalyst’s oxidative desulfurization (ODS) performance. We systematically investigate synthesis parameters, spatiotemporal yield, and defect characterization, and refines catalytic conditions. Post-acid-treated Ce/Zr-MOF-801-H displays augmented external surface area (189 m 2 g −1 ), and exposed acidic sites while upholding the outstanding intrinsic stability of the Zr-MOF-801 substrate. Under optimal conditions (60 °C, 6 min), Ce/Zr-MOF-801-H completely eliminates dibenzothiophene (1000 ppm S), with a turnover frequency of 39.3 h −1 and catalytic activity of 53.2 mmol g −1 h −1 , far surpassing Zr-UiO-66-H. It maintains a desulfurization rate of 96.6% after five cycles. FTIR spectroscopy, quenching experiments, and ESR spectroscopy reveal that the exposed Ce sites serve dual roles: (1) activating the substrate by reducing the electron density of sulfur atoms and (2) facilitating H 2 O 2 into hydroxyl and superoxide radicals, driving ODS. This strategy not only advances industrial ODS applications but also sheds light on the synthesis of MOF-based host–guest catalysts.