Synthesis of mesoporous WO3/TiO2 catalyst and its excellent catalytic performance for the oxidation of dibenzothiophene

A series of WO3/TiO2 catalysts with a pore structure were successfully synthesized. The catalysts were systematically characterized and it was found that different calcination temperatures had great effects on the pore structure of the catalysts. The catalyst presented a mesoporous structure after calcining at 550 °C (expressed as 550-WO3/TiO2) and had the largest specific surface area among the mesoporous catalysts. The oxidation of dibenzothiophene (DBT) with 550-WO3/TiO2 catalyst reached 100% under optimum conditions. After recycling for 6 times, the oxidation of DBT could still achieve a DBT removal of 96.7%, suggesting that the catalyst had good stability and recycle performance. In addition, DBT sulfone (DBTO2) was proven to be the only oxidation product of DBT after the reaction, as observed by the GC-MS analysis. The catalytic activities of the catalyst on different substrates were also investigated, and the activities decreased in the order: DBT > 4-MDBT > 4,6-DMDBT > BT.