Deoxydesulfurization of dibenzothiophene sulfone over cesium/MCM-41 catalysts

Dibenzothiophene sulfone, one of the products of the oxidative desulfurization of heavy oil, can be utilized through catalytic cracking. The object of the present study is to provide Cs/MCM-41 catalysts for the removal of sulfur dioxide from dibenzothiophene sulfone. Cesium oxide was deposited via an impregnation method on MCM-41, and the catalytic performances of the samples were investigated during the deoxydesulfurization of dibenzothiophene sulfone to biphenyl and sulfur dioxide gas. The influence of cesium loading on the basic properties of MCM- 41 was estimated by the temperature-programmed desorption of carbon dioxide. The dibenzothiophene sulfone conversions of the MCM-41, Cs(1 wt%)/MCM-41, Cs(3 wt%)/MCM-41 and Cs(10 wt%)/MCM-41 catalysts were 38.5, 52.1, 72.4 and 40.9%, respectively, which implies that the Cs(3 wt%)/MCM-41 catalyst has the highest activity. This result agrees with the finding of the basicity enhancement of MCM-41 with the addition of cesium, in which Cs(3 wt%)/MCM-41 exhibited a maximum number of basic sites.