Highly-efficient catalytic combustion performance of 1,2-dichlorobenzene over mesoporous TiO2–SiO2 supported CeMn oxides: The effect of acid sites and redox sites

Abstract

High specific surface area CeMn/TiO2–SiO2 catalysts were synthesized and evaluated for the catalytic combustion of 1,2-dichlorobenzene (o-DCB). Mesoporous TiO2–SiO2 supports were prepared by evaporation-induced self-assembly (EISA) method to investigate the promotion of Si on the acid properties of TiO2. Pore structures of TiO2–SiO2 were modulated by controlling the amount of hydrochloric acid during the preparation process of mesoporous supports, and the influence of structures and physicochemical properties of CeMn/TiO2–SiO2 catalysts on the activity and stability of o-DCB catalytic combustion were thoroughly studied. The results showed that Mn cations incorporated into CeO2 fluorite structure caused the formation of more active oxygen species. The active oxygen species and high specific surface area of catalysts played significant roles in o-DCB oxidation reaction. The influence of water on o-DCB catalytic combustion was also studied, and two different observations were obtained at low or high content of water. Due to deposition of Cl species on the surface of catalyst, CeMn/TiO2–SiO2 loses partial activity during o-DCB catalytic combustion, and most of activity could be recovered through Deacon reaction.