In situ fabrication of highly active γ-MnO2/SmMnO3 catalyst for deep catalytic oxidation of gaseous benzene, ethylbenzene, toluene, and o-xylene

Abstract γ-MnO 2 , SmMnO 3 , and γ-MnO 2 /SmMnO 3 catalysts were prepared by facile methods, wherein the SmMnO 3 (SMO) perovskite was synthesized through one-step calcination and the γ-MnO 2 /SmMnO 3 was formed by an in situ growth of γ-MnO 2 on the surface of SMO. These materials ware characterized by XRD, SEM-mapping, N 2 -adsorption, XPS and H 2 -TPR to investigate their textural properties. Compared with that of SMO and γ-MnO 2 , the γ-MnO 2 /SMO shows better performance for catalytic oxidation of aromatic VOCs in wet air (10 vol. %), which may be attributed to its higher surface molar ratio of lattice oxygen to adsorbed oxygen (O latt /O ads ) and better low-temperature reducibility. Besides, for γ-MnO 2 /SMO catalyst, a successive oxidation route and the inner principle of BETX (benzene, ethylbenzene, toluene, and o-xylene) oxidation were also revealed via various tests and a comprehension of dynamics investigation. Meanwhile, the experiments under simulated realistic exhaust conditions displayed that the γ-MnO 2 /SmMnO 3 is also a good catalyst with high stability for aromatic VOCs oxidation, and fulfilled endurability to high humidity (20 vol.%).