Removal of sulfur dioxide from dibenzothiophene sulfone over Mg-based oxide catalysts prepared by spray pyrolysis

Spray pyrolysis was used to prepare catalysts containing magnesium with mesopores. MgO-SiO₂, MgOAl₂O₃, and MgO-SiO₂-Al₂O₃ catalysts were synthesized using cetyltrimethylammonium bromide (CTAB) as a templating agent. The characteristics of the catalysts were examined by N₂ adsorption, XRD, XRF and the temperature-programmed desorption of carbon dioxide. The MgO-SiO₂ catalyst has well-developed mesopores, a large surface area and well dispersed magnesium oxide. The basic sites on the MgO-SiO₂ catalyst were much stronger than those on the MgO-SiO₂-Al₂O₃ and MgO-Al₂O₃ catalysts. The catalytic performance for the decomposition of dibenzothiophene sulfone (DBTS) to biphenyl and sulfur dioxide gas was examined in a fixed-bed reactor. The MgO-SiO₂ catalyst has the highest activity in the cracking of DBTS, which was attributed to the strong basicity due to the dispersed effect of magnesium oxide. Compared to the MgO catalyst, the mesoporous MgO-SiO₂ solid base can improve significantly the catalytic efficiency for the removal of sulfur dioxide from dibenzothiophene sulfone.