چكيده لاتين
The design of heterogeneous catalysts with high performance, chemical stability, and recyclability represents one of the key challenges in developing clean and efficient processes for fossil fuel purification. In this context, the present study focuses on the synthesis and evaluation of a novel catalytic nanocomposite with the structure SV2W10@MIL-101(Fe)-NH2, which has been designed and fabricated for the first time with the aim of optimizing the oxidative desulfurization (ODS) process. This nanocatalyst was constructed by encapsulating vanadium-containing polyoxometalate [SV2W10O40]4- (SV2W10) within the amino-functionalized metal–organic framework MIL-101(Fe)-NH2, thereby combining the outstanding properties of both components namely, high redox activity, large surface area, structural stability, and facile accessibility of active sites into a hybrid platform. The catalytic performance of the synthesized material was systematically evaluated and optimized for the removal of dibenzothiophene (DBT) and benzothiophene (BT) from a model fuel (n-octane). Key reaction parameters, including polyoxometalate loading, catalyst dosage, H2O2/DBT ratio, temperature, and reaction time, were thoroughly investigated, revealing the role of each parameter in enhancing process efficiency. Under optimal conditions, results demonstrated that in the presence of 25 mg of SV2W10@MIL-101(Fe)-NH2(3), acetonitrile as the extractive solvent, and H2O2 as the oxidant, the DBT conversion reached over 99% at 50 °C within 1 h. In contrast, the lower conversion of BT highlighted the selective nature of the synthesized structure toward bulkier sulfur-containing compounds. This finding underscores the rational and effective molecular-level design of the catalyst. Comprehensive characterization of the nanocomposite was conducted using FTIR, Raman, PXRD, TEM, FE-SEM, MAP, EDX, ICP-OES, BET, and TGA techniques, confirming the structural integrity, successful incorporation of polyoxometalate, favorable morphology, high thermal stability, and large accessible surface area. Furthermore, the recyclability of SV2W10@MIL-101(Fe)-NH2 was examined as an efficient heterogeneous catalyst with easy separation from the reaction medium. Notably, it maintained catalytic activity with negligible polyoxometalate leaching in the nanocatalyst after seven successive cycles. Overall, this nanocomposite represents an innovative catalytic platform with exceptional performance, high recyclability, and promising industrial potential, marking a significant step toward the advancement of novel desulfurization technologies and green fuel refining.
