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Herein, we report the high performance of Bi2O3interacted with ultrafine CeO2nanoparticles (NPs) for soot oxidation. With the increased Bi content, Bi2O3can be tuned from the amorphous phase to β-Bi2O3and finally to α-Bi2O3. The ultrafine CeO2NPs possessing abundant defects and large surface area are beneficial to forming β-Bi2O3. Our kinetic results show that the quantity of active oxygen species at the Bi–O–Ce interface is the determining factor for soot oxidation. Compared with other Bi2O3phases, the interaction between β-Bi2O3and CeO2can readily generate a larger quantity of active surface oxygen species with a higher turnover frequency. Consequently, the Bi2Ce8catalyst containing β-Bi2O3exhibits high activity and stability for soot oxidation and has the potential to be applied in real operations. Our discoveries provide insights into controlling active phase transformation and tuning interaction of metal oxides for various catalyst systems.

Herein, we investigate the De-NOxactivity of Pt/Ba/SnxCe1–xO2catalysts at high temperatures. Our results show that at high temperatures, their NOxstorage capacity (NSC), linked to the quantity of highly dispersed BaCO3species on the catalysts, determines the De-NOxactivity instead of the NOxoxidation and reduction ability. Moreover, we identify that monodentate nitrate species are more stable than free ion nitrate species on the Ce-containing catalysts. Thus, the presence of monodentate nitrate species is beneficial to improve the H2O and CO2tolerance by inhibiting the latter ones’ competitive adsorption on NOxstorage sites. Compared with other catalysts, Pt/Ba/Sn0.8Ce0.2O2possesses the larger amount of highly dispersed BaCO3species, and especially, more monodentate nitrate species are formed on it during the NOxstorage period. Thus, it exhibits the superior De-NOxperformance with NOxremoval percentage over 86% in the presence of H2O and CO2at 350∼500 °C.