Study on the Catalytic Soot Combustion Properties of Cerium- and Lanthanum-Based Composite Oxide Catalysts

Three different types of carbon soot catalysts, CeFeCo, La-Mn-O and BiCeO, were prepared by impregnation, hydrothermal synthesis and co-precipitation methods. By comparing and analyzing the characterization results of the three samples, such as scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and H₂-temperature programmed reduction (TPR), it can be found that La-Mn-O sample has the largest proportion of chemisorbed oxygen, CeFeCo sample has the largest metal ion content, and Ce³⁺ content is higher than BiCeO sample. It can be found that CeFeCo has the lowest reduction peak at about 283 ℃ in the H₂-TPR. Finally, the activities of the three samples were evaluated by a temperature-programmed oxidation reaction system. The temperatures required to catalyze the oxidation of 50% soot for CeFeCo, La-Mn-O and BiCeO samples in tight contact were 329, 355 and 374 ℃, respectively, which were reduced by 265, 239 and 220 ℃, compared with the blank group. This indicates that all three catalysts were successfully prepared and had good catalytic soot combustion performance, and especially the CeFeCo catalyst exhibited the best low-temperature catalytic combustion performance.