Catalytic aerobic desulfurization of fuels in the presence of nanosized mixed carbide FeWC

Nanosized mixed tungsten-iron carbide (FeWC) was successfully applied in aerobic oxidative desulfurization. The combination of catalytically active centers responsible for the activation of oxygen and the oxidation of sulfur-containing compounds made it possible to obtain a highly efficient catalyst. The catalyst was synthesized by microwave irradiation, allowing to obtain a nanoscale catalyst in just 15 min. The catalyst was characterized in detail by a variety of methods: XRD, HRTEM, EDX, SEM, XPS, and low-temperature nitrogen adsorption/ desorption. The key factors influencing the dibenzothiophene (DBT) oxidation were investigated. Under opti-mized conditions DBT conversion was 100% in 1 h at 130 degrees C, 6 atm. The possible mechanisms including oxygen activation, alkyl peroxide formation, and substrate oxidation by tungsten peroxo-complexes were discussed. The catalyst retains its activity for at least 5 cycles of oxidation-regeneration. Aerobic oxidative desulfurization of straight-run gasoline in the presence of FeWC was performed and sulfur content was reduced from 995 to 6 ppm.

Automated summary

Nanosized mixed tungsten-iron carbide (FeWC) was synthesized by microwave irradiation and used as an efficient catalyst for aerobic oxidative desulfurization. The catalyst showed high activity for dibenzothiophene oxidation under optimized conditions. The possible mechanisms for oxygen activation and substrate oxidation were discussed. The presence of FeWC in straight-run gasoline resulted in a significant reduction in sulfur content.