Facile template fabrication of Fe-Mn mixed oxides with hollow microsphere structure for efficient and stable catalytic oxidation of 1,2-dichlorobenzene

A series of novel Fe-Mn mixed oxide hollow microspheres are synthesized by a hard template approach and used for catalytic oxidation of 1,2-dichlorobenzene (DCB). The obtained materials are characterized by FAAS, XRD, N2 sorption, SEM, TEM, in situ FT-IR and XPS techniques. The results show that the proportions of Fe/Mn can make great influence on the physicochemical properties of Fe-Mn mixed oxides, and thus, affecting their catalytic performances in DCB oxidation. In particular, the FeMn20 catalyst (molar ratio Mn/(Fe + Mn) ≈ 20%) exhibits the highest catalytic performance (i.e., high catalytic activity and CO2 selectivity, long-term stability and good water-resistant ability). In situ FT-IR measurements and XPS results reveal that the FeMn20 catalyst shows almost no obvious carbon deposition after long-term testing. The excellent catalytic performance of FeMn20 catalyst is attributed to the combined effects of several factors such as small crystallite size, hierarchical porous structure and high surface active oxygen concentration. It is reasonable for us to believe that such Fe-Mn mixed oxide hollow microspheres represent a very promising catalyst system for total catalytic oxidation of chlorinated volatile organic pollutants.