Oxidative desulfurization of diesel using promising heterogeneous tungsten catalysts and hydrogen peroxide

• Supported anions with Keggin- and Dawson-type structure catalyze OD using H2O2.
• Titania-supported tungsten catalysts show the best activity for the OD of diesel fuel.
• A mechanism via monoperoxo tungsten species is proposed for the OD process using H2O2.

Tungsten supported catalysts were evaluated in the oxidative desulfurization (OD) of diesel fuel (320 ppmw S) using hydrogen peroxide as oxidizing agent. These catalysts were prepared by equilibrium adsorption of tungsten from solution of tungsten (VI) oxide, tungstic acid, ammonium tungstate, ammonium metatungstate and phosphotungstic acid in supports such as alumina, silica, titania, titania–alumina and zirconia. The sulfur removal from diesel fuel was achieved up to 93.8 ppmw (70.7%) by oxidation under mild reaction conditions followed by acetonitrile extraction. The effects of the tungsten precursor, support, and solution concentration of tungsten used to prepare catalysts were evaluated. According to the results obtained a mechanistic proposal for this reaction is described.