Indexed by:Journal Papers

Date of Publication:2020-01-15

Journal:APPLIED SURFACE SCIENCE

Included Journals:EI、SCIE

Volume:500

ISSN No.:0169-4332

Key Words:Catalytic oxidation; VOCs; Benzene; Todorokite manganese dioxides; Samarium

Abstract:Catalytic VOCs oxidation is primarily developed towards the synthesis of active, stable and economical materials that work efficiently at low temperatures. Herein, an active todorokite-type MnO2 (T-MnO2) was prepared for the catalytic oxidation of gaseous benzene for the first time and the effect of samarium (Sm) modification was investigated. The T-MnO2 was much more active than the reported transition metal oxide counterparts, complete removal of 237 ppm of benzene achieved at a low reaction temperature of 175 degrees C and a very high space velocity of 120 L.g(-1).h(-1). According to ICP-OES, XRD and ATR, Sm existed as amorphous Sm2O3 in SmMnO. Of all tested samples, Sm0.01MnO (atomic ratio of Sm/Mn was 0.01) performed the best, exhibiting 100% conversion for 229 ppm of benzene at 150 degrees C and above under 120 L.g(-1).h(-1), and almost no residual benzene was detected at 200 degrees C and above even under 240 L.g(-1).h(-1). According to C6H6-TPD, XPS, H-2-TPR and O-2-TPD, the origin of the excellent performance of the Sm0.01MnO came from it having a high benzene adsorption capacity, strong binding with benzene molecules and plenty of active surface oxygen. Moreover, the effect of concomitant water on catalyst activity was elucidated.