Heterogeneous oxidative desulfurization of diesel oil by hydrogen peroxide: Catalysis of an amphipathic hybrid material supported on SiO2

• [Bmim]3PW12O40/SiO2 is an outstanding catalyst in oxidative desulfurization.
• [Bmim]3PW12O40/SiO2 is an amphipathic heterogeneous catalyst.
• Catalyst can stay at the interface to adsorb reactants from water and oil phase.
• Heterogeneous catalyst can easily recovered by centrifugation after reaction.
• [Bmim]3PW12O40/SiO2 can reused for 7 runs without a slight decrease in activity.

Here we described a catalytic system for oxidation of benzothiophene (BT), dibenzothiophene (DBT), or 4,6-dimethyl-dibenzothiophene (4,6-DMDBT) in model oil by catalysis using a hybrid material ([Bmim]3PW12O40) supported on SiO2. The [Bmim]3PW12O40 was synthesized by reacting H3PW12O40 with 1-butyl-3-methyl imidazolium bromide. The experimental results demonstrated that the SiO2-supported catalyst with 20 wt.% [Bmim]3PW12O40 exhibited a high catalytic activity, achieving the DBT, 4,6-DMDBT, and BT conversions of 100%, 100%, and 71.6% at 50 °C, atmospheric pressure, and H2O2/DBT molar ratio of 3.0 in 100 min. The catalyst was recycled conveniently by filtration and reused for seven times without a significant decrease on the activity. The reused catalyst can recover the oxidation activity only by drying at 100 °C for 4 h. This extraction and catalytic oxidative desulfurization (ECODS) system can remove 98.2% sulfur-contenting compounds from the diesel oil with sulfur-containing of 445 mg/L.

The [Bmim]3PW12O40/SiO2 is a heterogeneous catalyst possess hydrophilic and hydrophobic properties, and it can stay at the interface of the water and organic phase and does not dissolve in both of them. The catalyst can adsorb H2O2 and 4,6-DMDBT simultaneously to improve the oxidative reaction.Figure optionsDownload as PowerPoint slide