Preparation of Mn-V-O binary oxides and their catalytic performance for aerobic oxidative desulfurization

Aerobic Oxidative Desulfurization (AODS) represents an economical and sustainable approach for the desulfurization of petroleum distillates, requiring high-performance catalysts to convert sulfides into sulphones under mild reaction conditions. The sheet-like Mn-V-O binary oxides were synthesized using a straightforward hydrothermal process. The crystal phase, morphology, and surface properties of the catalyst were examined using various techniques, including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The desulfurization performance over the catalyst of Mn-V-O binary oxides was assessed using oxygen as the oxidant, and the effects of reaction temperature, catalyst dosage, oxygen flow rate, and sulfide type on the desulfurization rate were investigated. The results indicate that when the reaction temperature is maintained at 110 °C, with 20 mL of model oil, 0.04 g of catalyst and an oxygen flow rate of 150 mL/min, the desulfurization rate can achieve 92.5%. The order of removal rate for different sulfides is as follows: dibenzothiophene (DBT) > 4,6-dimethyldibenzothiophene (4,6-DMDBT) > benzothiophene (BT). The catalyst can be reused up to five times while maintaining a desulfurization activity above 90%. Free radical capture experiments have demonstrated that the superoxide radicals are generated in the presence of the catalyst and oxygen, which effectively oxidize the DBT to DBTO₂.