The use of 18O2 to investigate the soot oxidation process on Co3O4, Co3O4-CeO2 and CeO2 catalysts in tight contact conditions

The reaction mechanism of soot oxidation in tight contact conditions and that of oxygen mobility in the crystal lattices of Co3O4, Co3O4-CeO2 and CeO2 was studied. The TPIE results suggested that oxygen mobility is the highest in the crystal lattice of Co3O4-CeO2. The Isotopic Transient Kinetic Analysis (ITKA) results suggested that soot oxidation proceeds mainly with the use of surface adsorbed oxygen on Co3O4, with lattice oxygen on CeO2 but without excluding the participation of small amounts of surface adsorbed oxygen, and in the case of Co3O4-CeO2 with the participation of both adsorbed surface and lattice oxygen.