Characterization and reactivity of Mn-Ce-O composites for catalytic ozonation of antipyrine

Mn-Ce-Ocomposites were prepared by a redox-precipitation method and used as a catalyst for ozonation of antipyrine (AP) in aqueous solution. The phase composition, surface area and electron transfer ability of the products are dependent on the molar ratio of precursors. Mn-Ce-O(8/2) exhibited the highest activity for the degradation and mineralization of AP with ozone, which can be attributed to its high electron transfer ability. The decomposition of ozone into (OH)-O-center dot can be accelerated through the electron transfer between ozone and catalyst. The refractory intermediates in ozonation and catalytic ozonation were identified and the catalytic performances of Mn-Ce-O(8/2) for these intermediates were also investigated. The hydroxyl radical reaction played an important role in the degradation of the refractory intermediates, and the contribution of surface reactions was strengthened with decreasing pH. A possible mechanism for the catalytic ozonation of AP was proposed.