Recent advances in performances and mechanisms of cerium-based oxide catalysts for catalytic combustion of soot particles released from diesel engines

With the increasingly strict environmental protection regulations and the improvement of people’s awareness of environmental protection, the serious environmental pollution caused by soot particles from diesel vehicle exhaust has attracted people’s attention. Catalytic purification technology is one of the most effective ways to eliminate soot particles and the research and development of highly effective catalysts is one of the key factors for determining the application of this technology. In recent years, cerium-based oxide catalysts have been widely used for catalytic combustion of diesel soot particles due to their excellent oxidation-reduction performance, suitable surface acidity, and high oxygen storage/release capacity. The researches focusing on highly active essence of the cerium-based oxide catalysts in soot combustion are helpful to understand the fundamental theories of catalytic processes of soot combustion and provide scientific guidances for the optimization of existing catalysts and design of new-type catalysts. In this review, the recent research progress of cerium-based oxide catalysts for diesel soot combustion is summarized, including single cerium oxide catalyst and cerium-based oxide catalysts modified by rare earth metals, transition metals, noble metals and alkali (alkaline earth) metals. Meanwhile, the reaction mechanisms of above-mentioned catalysts are also summarized. Finally, the problems and development directions of cerium-based oxide catalysts for soot combustion are proposed and prospected.