Insight into the better performance of Co than Pt on Ce-Sn catalyst for soot oxidation

In this study, a 3 %Co/Ce-Sn catalyst (T50 = 456 degrees C) exhibited much better performance than a noble 1 %Pt/CeSn catalyst (T50 = 510 degrees C) for soot oxidation. The 3 %Co/Ce-Sn catalyst also performed excellent poisoning resistances to H2O and SO2. Characterization results revealed that the introduction of Co induced more oxygen defects than Pt for the catalyst, which could be favorable to activating the surface chemisorbed oxygen to produce active oxygen species. Moreover, it was also identified that the active oxygen species govern the oxidation process of NO to NO2, which could then facilitate soot oxidation by a NO2-assisted mechanism. Our results provide significant understanding of the design of low-cost and high-performance catalyst for soot oxidation, and the obtained 3 %Co/Ce-Sn catalyst would be a promising candidate for the control of soot in diesel vehicles.

Automated summary

In this study, a 3 %Co/Ce-Sn catalyst displayed higher efficiency in soot oxidation compared to a 1 %Pt/CeSn catalyst. The 3 %Co/Ce-Sn catalyst also exhibited strong resistance to H2O and SO2 poisoning. The introduction of Co induced more oxygen defects, enabling the activation of chemisorbed oxygen and the production of active oxygen species. Furthermore, it was discovered that the oxidation process of NO to NO2 was governed by active oxygen species, which facilitated soot oxidation through a NO2-assisted mechanism. These findings provide valuable insights for the design of cost-effective and high-performance catalysts for soot oxidation, with the 3 %Co/Ce-Sn catalyst being a promising candidate for controlling soot in diesel vehicles.