Synergistic Deep Extractive Oxidative Desulfurization of Fuel Over PW ₁₁ Mn@MOF‐525

ABSTRACT

Deep desulfurization of fuels is critical for environmental protection and clean energy production. Herein, a novel composite catalyst, PW ₁₁ Mn@MOF‐525, was synthesized by in situ encapsulation of a manganese‐substituted Keggin‐type polyoxometalate PW ₁₁ Mn within a zirconium‐based metal–organic framework (MOF‐525). The catalyst was thoroughly characterized by various methods, confirming uniform dispersion of PW ₁₁ Mn within the MOF pores without framework collapse. The PW ₁₁ Mn@MOF‐525 composite was applied for extractive catalytic oxidative desulfurization (ECODS) of dibenzothiophene (DBT) using H ₂ O ₂ as oxidant and acetonitrile as extractant. Under optimized conditions, the composite achieved 99.2% DBT removal within 80 min, owing to synergistic H ₂ O ₂ activation by the Lewis acidic Zr‐oxo clusters and redox‐active PW ₁₁ Mn clusters. Kinetic analysis revealed pseudo‐first‐order behavior with an activation energy of 57.66 kJ·mol ⁻¹ . Radical trapping experiments identified hydroxyl radicals (·OH) as the dominant active species. The catalyst exhibited excellent recyclability, maintaining 94.9% DBT removal after five cycles with negligible leaching. This work demonstrates that encapsulation of polyoxometalates within MOF‐525 is a promising strategy for efficient and stable deep oxidative desulfurization.