A comparative investigation of SO2 oxidative transfer over CuO with a CeO2 surface.

To further improve the catalytic desulfurization function of the Mg-Al spinel sulfur transfer agent in a fluid catalytic cracking (FCC) unit, the reaction paths of SO 2 oxidation by O 2 over the metal oxide surface of CuO (111) and CeO 2 (111) were investigated. In reference to the fact that SO 2 reacting with O 2 over CuO was a Mars-van Krevelen cycle, a similar reaction law for SO 2 oxidation over CeO 2 was also verified by characterization methods (e.g., IR, XPS). Meanwhile, the molecular simulation results indicated that the rate-control step of SO 2 oxidation over CeO 2 (111) and CuO (111) was a SO 3 desorption step. The lower energy barrier in the rate-control step corresponded to better catalytic performance; hence, it could explain the reason that CeO 2 had a better sulfur oxidization transfer performance than CuO. [ABSTRACT FROM AUTHOR]