Research progress on preparation of cerium-based oxide catalysts with specific morphology and their application for purification of diesel engine exhaust

The elimination of pollutants from diesel exhaust has received widespread research attention as they cause serious air pollution and pose a threat to human health. Catalytic post-treatment technology is one of the most effective and universal technologies to treat diesel exhaust pollutants. The design and development of efficient and low-cost catalysts is the key factor to realize the wide application of catalytic post-treatment technology. Cerium (Ce)-based oxides with specific morphologies are widely used to eliminate pollutants in diesel vehicle exhaust due to their unique physical and chemical properties, such as high catalytic activity, low cost and non-toxicity. In this review, the preparation methods of Ce-based oxide materials with specific morphologies, such as nanoparticles, nanocubes, nanorods, nanofibers, and multi-stage pores, are introduced in detail, and the research progress on using these catalysts for the removal of carbon monoxide, hydrocarbons, soot particles, nitrogen oxides, and other pollutants from diesel exhaust is reviewed in detail. Finally, the unresolved issues associated with using Ce-based oxide catalysts with a specific morphology to catalytically remove pollutants from diesel exhaust are highlighted, and future application prospects and development directions are discussed.