Cordierite/Aluminum Borate Whiskers/Co_0.8Fe<italic>_x</italic>Ce_0.2-<italic>_x</italic>Cr₂O₄ Catalysts: Preparation and Filtration Catalytic Performance for Carbon Soot

With increasingly strict regulations on exhaust emissions, the higher requirements have been built for filtration of diesel particulate filter (DPF) because traditional DPF cannot meet the demand for precise filtration of nanoparticles in exhaust. In this study, a series of Co0.8FexCe0.2-xCr2O4 spinel-type catalysts were 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 concentrations of oxygen species (oxygen vacancies), Co3+ and Cr6+ on the catalyst surface and enhancing reaction activity. Temperature of carbon soot particles at 50% conversion (T50=446 ℃) is significantly lower than that of the blank cordierite sample (T50=567 ℃). Five cyclic stability tests show that the catalysts have good stability and CO2 selectivity (86%-94%). In conclusion, this unique hierarchical microstructure exhibits a unity of efficient particle filtration and low temperature catalytic combustion performance, with potential application in the field of DPF.