چكيده لاتين
Compounds from fuels to reduce the emission of sulfur dioxide (SO₂), a gas that contributes significantly to acid rain formation and poses risks to human health during combustion processes. In this context, oxidative desulfurization (ODS) has emerged as an effective and low-cost method for removing organosulfur compounds under mild conditions. Metal–organic frameworks (MOFs), owing to their porous structures, high surface areas, and tunable chemical functionalities, have attracted attention as ideal supports for the design of heterogeneous catalysts in ODS reactions. Meanwhile, polyoxometalates (POMs) are considered excellent catalytic components due to their high oxidative potential, thermal stability, and structural versatility. In this study, the polyoxometalate H₃(n-Bu₄N)₄[PMo₁₁O₃₉] was encapsulated within a MIL-101(Cr) MOF using a "bottle-around-ship" strategy to fabricate a heterogeneous catalyst for ODS. In this approach, the POM species was introduced into the reaction mixture during the synthesis of the MOF, allowing the MIL-101 framework to form around the POM. The resulting catalyst composite was characterized using Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). Scanning electron microscopy (SEM) was employed to analyze the morphology, while Brunauer–Emmett–Teller (BET) analysis was used to assess surface area and porosity. The POM loading within the MOF structure was evaluated by inductively coupled plasma mass spectrometry (ICP-MS). The catalytic performance of the synthesized composite was investigated for the removal of dibenzothiophene (DBT), a model sulfur compound, under both thermal reflux and ultrasonic-assisted conditions. Reaction efficiency was monitored via UV-Vis spectroscopy, and various oxidants, temperatures, and reaction times were tested to determine optimal conditions. Under optimal conditions (75 minutes, hydrogen peroxide as oxidant, and 50 °C), the desulfurization efficiency reached approximately 98%, confirming the high catalytic activity of the heterogeneous system. Additionally, recycling experiments demonstrated that the catalyst retained its structural integrity and catalytic efficiency over eight consecutive cycles without significant performance loss
