Synthesis and performance of transition metal based perovskite catalysts for diesel soot oxidation

Abstract

In present investigation, the effect of the intrinsic factors including the structure, nature of B-site ions in the four systems LaCoO3, LaNiO3, LaFeO3 and LaZnOy perovskite-type oxide catalysts, and the external factors of catalyst-soot contacting model, and the operating parameters such as air flow rate and temperature on the catalytic performances for the combustion of diesel soot were reported. The catalysts were characterized by XRD, FTIR, SEM, and N2-sorption. Activity of the catalyst for soot oxidation was evaluated on the basis of light off temperature characteristics Ti, T50 and T100. LaCoO3, La-FeO3 and LaNiO3 samples possessed the perovskite structure, and gave high activities for the total oxidation of soot below 445 °C. Whereas, LaZnOy catalyst was not indicating the ABO3 perovskite structure and existed as a mixture of metal oxides. The activity order in decreasing sequence of the catalyst was as follows: LaCoO3>LaFeO3>LaNiO3>LaZnOy. SEM pictures of the perovskite samples showed that the particles sizes were close to 100 nm.