School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
Phosphotungstic acid/activated carbon (PTA/AC) catalysts with various AC sizes or PTA content have been synthesized and characterized by N physisorption, X-ray diffraction, Fourier transform infrared spectroscopy and temperature programmed desorption of ammonia. These catalysts were then evaluated in terms of the removal of dibenzothiophene (DBT) by ultrasound-assisted oxidative desulfurization process. The results showed that the DBT conversion obviously increased with the decrease of AC support size and the increase of PTA content. After supporting PTA on AC, the DBT conversion can be improved by 38.9% after ultrasound irradiation for 10 min. In addition, the stability tests of PTA/AC showed that the catalytic oxidative activity of PTA/AC was nearly kept constant after ultrasound irradiation for 20 min, which makes it a promising catalyst to use in ultrasound-assisted oxidative desulfurization process.