Andrzej Adamski

Background: An abatement of emission of particulate matter (mainly soot) is a challenging problem of nowadays society. An active and cheap catalytic system for soot combustion can help in solving this problem. Objective: The aim of this study was to investigate influence of composition of Mn3-xFexO4 (x = 0 – 3) oxides exhibiting spinel structure on their catalytic properties in soot combustion. Methods: Materials were synthesized by coprecipitation and further thermal treatment. Their structure was verified by X-ray diffraction and Raman spectroscopy. The obtained catalysts were tested in model soot oxidation (Printex U) in both tight and loose contact modes. Results: It was found that different mechanisms of soot combustion occurred dependently on a chosen contact mode. Conclusion: It was confirmed that in the case of tight contact (TC) a coexistence of divalent manganese and iron species was decisive for catalytic activity, whereas a presence of trivalent manganese centers was crucial in the case of loose contact (LC). Mn1.2Fe1.8O4 was found to be the most active catalyst.