Abstract: With the increasingly strict regulations on exhaust emissions, the higher requirements have been built for the filtration of diesel particulate filters (DPF), and traditional DPF filters can not match the demand for precise filtration of nanoparticles in exhaust. In this study, Co_0.8Fe_xCe_0.2-xCr₂O₄ series spinel-type catalyst was loaded on aluminum borate whiskers by hexadecyl dimethyl ammonium bromide (CTAB)-assisted co-precipitation method. The unique hierarchical microstructure design of “whisker enhanced filter-bimetallic doping catalytic oxidation” achieves a combination of efficient filtration performance and low-temperature catalytic performance, enabling catalytic oxidation of carbon soot particles at lower temperatures. Fe and Ce co-doping produces significant synergistic effects, increasing the concentrations of oxygen species (oxygen vacancies, Co³⁺ and Cr⁶⁺) on the catalyst surface and enhancing reaction activity. This hierarchically microstructure integrates the efficient filtration performance and low-temperature catalytic performance together, which demonstrates the catalytic purification of soot particles at lower temperature, and the co-doping of Fe and Ce produces a significant synergistic effect, optimizing the concentration and reactivity of oxygen species (oxygen vacancy, Co³⁺, Cr⁶⁺) on the surface of the catalyst. The temperature of carbon soot particles 50% conversion (T₅₀=446 ℃) was significantly better than that of the blank cordierite sample (T₅₀=567 ℃). Five cyclic stability testing shows that the catalysts have good stability and CO₂ selectivity (86%-94%). This unique hierarchical microstructure effectively shows a unity of efficient particle filtration and low temperature catalytic combustion performance, and has potential application in the field of diesel particulate filter (DPF).

Key words: soot particle, cordierite, aluminum borate whisker, catalytic oxidation, filtration