Textural-structural properties and soot oxidation activity of MnOx-CeO2 mixed oxides

A series of MnOx-CeO2 mixed oxides were prepared using a sol-gel method followed by calcinations at various temperatures. The soot oxidation activities were measured in different NO concentrations under loose contact conditions. A quasi-parabolic curve is observed for the apparent dependency of activity on the catalyst surface area. As the surface area is below 8 m(2)/g, the soot oxidation is limited by the availability of NO2 due to the separation and sintering of the mixed oxides. The rate-determining step turns to be NO2 reaction with soot for the high-surface-area catalysts. (c) 2010 Elsevier B.V. All rights reserved.