Co3O4-CeO2 heterogenous interfaces as a high-efficient catalyst for soot oxidation

Developing advanced catalysts for efficiently eliminating soot particles could be significant for achieving the goal of Euro 6 and China VIB. Co3O4/CeO2 nanocomposites containing Co3O4-CeO2 interfaces are considered as efficient catalysts for removing soot particles, while the role of Co3O4-CeO2 interfaces is still unclear. In this study, Co3O4/CeO2 nanocomposites with different contents of Co3O4-CeO2 interfaces were prepared to investigate the role of Co3O4-CeO2 interfaces in promoting soot oxidation. Experimental results show that Co3O4-CeO2 interfaces can efficiently eliminate soot nanoparticles, while the content of which weakly influences the elimination temperatures and products selectivity. It was found that the reaction dynamic and intrinsic activity are found to change with the content of Co3O4-CeO2 interfaces. Further investigations demonstrate that a few amounts of Co3O4-CeO2 interfaces can significantly increase the O2-preferred active sites, but not significantly enhance the movability of active oxygen species and the activation of NO. Increasing Co3O4-CeO2 interfaces can enrich the NO-preferred active sites and enhance the movability of active oxidative species. As a result, rich Co3O4-CeO2 interfaces lead to low soot-eliminating temperatures (T50: 407 degrees C) and high intrinsic activity (TOF: 0.99 h-1), while a few amounts of Co3O4-CeO2 interfaces perform low soot-eliminating temperatures (T50: 403 degrees C) with low intrinsic activity (TOF: 0.68 h-1). Results of this work might be meaningful in designing robust nanomaterials with heterogenous interfaces.