Effect of Co3O4 on the kinetics of thermal decomposition of diesel particulate matter

Abstract

Catalytic combustion of diesel particulate matter was performed over a cobalt (II,III) oxide (Co3O4) catalyst in a thermogravimetric analysis system, at distinct heating rates and catalyst contents. Kinetic parameters were then estimated for several experimental conditions, based on the Flynn-Wall-Ozawa method. These catalysts show a good activity for diesel particulate oxidation, which is observed to be a factor of the cobalt (II,III) oxide content. The results show that the addition of a catalyst has little effect on volatilisation and oxidation of soluble organic fraction but boosts the soot oxidation process. Considering the thermal gravimetric characteristics of non-catalysed particulates as a baseline, with the increased trend of the catalyst (cobalt (II,III) oxide) contents of 10 and 15 wt%, the ignition temperature, the temperature corresponding to the weight loss peak and the burnout temperature of the soot oxidation would descend at the same time. The activation energy observed for non-catalysed and 15 wt% cobalt (II,III) oxide-catalysed reactions are 212·6 and 172·3 kJ/mol respectively, which also confirms the catalytic activity of the catalyst for diesel particulate oxidation.