Ozone-assisted oxidation of methyl ethyl ketone over mesoporous MnO_x/γ-Al₂O₃ catalysts

Mesoporous MnO_x/γ-Al₂O₃ (MA) catalysts were synthesized using two different manganese precursors (acetate and nitrate forms) to remove methyl ethyl ketone (MEK) via ozonation at room temperature. The MA catalyst prepared with the acetate precursor (MA-A) showed higher catalytic performance in the decomposition of MEK and ozone compared with the MA catalyst prepared with the nitrate precursor. Based on the N₂ physisorption and high-resolution transmission electron microscopy, the superior activity of MA-A could be attributed to its large surface area and pore volume, as well as the increased dispersion of MnO_x particles. In addition, an appropriate strength of surface acid sites and a higher ratio of active Mn³⁺/Mn⁴⁺ on MA-A resulted in the improved activity.