Study of the preparation of CuWO₄/C composite and it's application in oxidative desulfurization of model oil

The CuWO₄/C composite was synthesized via a simple mixing-calcination method and characterized by various techniques including X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller and so on. The removal of dibenzothiophene (DBT) in model oil was studied by using CuWO₄/C as catalysts, hydrogen peroxide as oxidant, 1-ethyl-3-methylimidazole ethyl sulfate (EMIES) ionic liquid (IL) as the extractant. Results indicated that the CuWO₄/C composite exhibited a much higher desulfurization ratio than pure CuWO₄ under the same experimental conditions. The influence of reaction temperature, amount of hydrogen peroxide, amount of extractant on the desulfurization efficiency were investigated. The results indicated that under the optimal reaction conditions of 5 mL model oil, 0.02 g of CuWO₄/C, 0.2 mL of hydrogen peroxide, 1.0 mL of extractant, reaction temperature 70℃ and reaction time 180 min, the desulfurization efficiency of CuWO₄/C was 98.2%. The catalyst could be recycled 4 times without a significant decrease in activity.