Soot Combustion over Nanostructured Ceria with Different Morphologies

Abstract

In this study, nano-structure ceria with three different morphologies (nanorod, nanoparticle and flake) have been prepared by hydrothermal and solvothermal methods. The ceria samples were deeply characterized by XRD, SEM, TEM, H2-TPR, XPS and in-situ DRIFTS, and tested for soot combustion in absence/presence NO atmospheres under loose and tight contact conditions. The prepared ceria samples exhibit excellent catalytic activities, especially, the CeO2 with nanorod (Ce-R) shows the best catalytic activity, for which the peak temperature of soot combustion (Tm) is about 500 and 368 °C in loose and tight contact conditions, respectively. The catalytic activity for Ce-R is higher than that of the reported CeO2 catalysts and reaches a level that of precious metals. The characterization results reveal that the maximal amounts of adsorbed oxygen species on the surface of the nanostructure Ce-R catalyst should be the crucial role to decide the catalytic soot performance. High BET surface area may also be a positive effect on soot oxidation activity under loose contact conditions.

Enhanced Catalytic Performance of Manganese and Cobalt Co–doped CeO2 Catalysts for Diesel Soot Oxidation

“…The reaction between intermediate and either O ads or gaseous O 2 produces CO/CO 2 . At the same time, ceria can act as oxygen buffer by providing oxygen with shifting between Ce 4+ and Ce 3+ during the reaction …”

“…At the same time, ceria can act as oxygen buffer by providing oxygen with shifting between Ce 4 + and Ce 3 + during the reaction. [42] Therefore, from the above proposed mechanism it is anticipated that the surface adsorbed oxygen species and high concentration of Ce 3 + /Ce 4 + ions play key role in the soot oxidation. In this work, we have successfully prepared codoped ceria catalysts and tested towards soot oxidation under tight contact conditions.…”

Ag/CeO2 Composites for Catalytic Abatement of CO, Soot and VOCs

“…In Ref. [96] hydrothermal and solvothermal methods were used to prepare nanostructured ceria with different morphology (nanorod, nanoparticle, and flake). The nanorod sample showed the best catalytic activity (soot combustion temperatures for TC and LC modes were 368 and 500 °C, Comparing to the morphologies in groups 1 and 2, the three-dimensional shape of SA stars may involve more of the soot cake layer that can be a reason for enhancement of the total number of contact points and higher catalytic activity ( Figure 5).…”

“…In Ref. [96] hydrothermal and solvothermal methods were used to prepare nanostructured ceria with different morphology (nanorod, nanoparticle, and flake). The nanorod sample showed the best catalytic activity (soot combustion temperatures for TC and LC modes were 368 and 500 °C, A comparison of the catalytic performance of pure ceria with different morphology under LC conditions was carried in [60], and the results were compared to those reported in Refs.…”

“…In Ref. [96] hydrothermal and solvothermal methods were used to prepare nanostructured ceria with different morphology (nanorod, nanoparticle, and flake). The nanorod sample showed the best catalytic activity (soot combustion temperatures for TC and LC modes were 368 and 500 • C, respectively) that was attributed to the maximal amount of adsorbed oxygen species on its surface.…”