Kinetic Analysis of Devolatilized Diesel-Soot Oxidation Catalyzed by Ag/Al(2)O(3) and Ag/CeO(2) Using Isoconversional and Master-Plots Techniques

[Image: see text] This work presented the kinetic analysis of devolatilized diesel-soot combustion accelerated by Ag/Al(2)O(3) and Ag/CeO(2) catalysts. Isoconversional and master-plots techniques were employed to estimate activation energy and identify the reaction model. The apparent activation energy of uncatalyzed soot oxidation was 101.85 kJ/mol, and it was reduced to 61.85 and 82.78 kJ/mol for the combustion catalyzed by Ag/Al(2)O(3) and Ag/CeO(2), respectively. The reaction-order model, f(α) = (1– α)n, with n of 1.4, 1, and 1 showed the best fit for the uncatalyzed soot oxidation and soot oxidation catalyzed by Ag/Al(2)O(3) and Ag/CeO(2), respectively. The proposed single-step reaction models were quite capable of reproducing experiments for the uncatalyzed soot oxidation and soot oxidation catalyzed by Ag/CeO(2). In the presence of Ag/Al(2)O(3), the oxidation rate at the first 20% of conversion was faster than the 1st-order reaction reflecting that the soot was rapidly oxidized by highly active species generated by Ag/Al(2)O(3). The oxidation of the remaining soot closely followed the 1st-order reaction mechanism.