Efficient and rapid removal of thiophene sulfides from fuel using zirconia-loaded phosphotungstic acid

In this study, a new type of composite was synthesized <i>via</i> the sol-gel method. The structure and properties of the composite were analyzed using X-ray diffraction, scanning electron microscopy, nitrogen isothermal adsorption and desorption tests, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Characterization results showed that phosphotungstic acid (PW₁₂) was successfully loaded on zirconium dioxide (ZrO₂). The oxidative desulfurization performance of 500 ppm dibenzothiophene (DBT) was studied with H₂O₂ as the oxidant and <i>x</i>PW₁₂/ZrO₂ as the catalyst. Under optimal conditions (<i>T</i> = 60 °C, O/S = 2 and <i>m</i> = 0.03 g), the desulfurization rate reached 97.85% within 20 min, and the activity did not decrease significantly after 8 cycles. The kinetics of the reaction was studied at different temperatures. Results showed that the oxidation rate conforms to quasi-first-order kinetics and the apparent activation energy is 23.32 kJ mol^-1. Therefore, the composite material is expected to be a catalyst for oxidative desulfurization.