Improved reactivity for toluene oxidation on MnOx/CeO2-ZrO2 catalyst by the synthesis of cubic-tetragonal interfaces

[Display omitted] •Cubic-tetragonal interface in Ce-Zr solid solution was successfully synthesized.•The catalyst interface promoted the interaction between surface Mn and Ce species.•The catalyst interface improved catalytic performance for toluene oxidation.•Higher surface lattice oxygen concentration was obtained on the interfaces. In this study, the CeO2-ZrO2 solid solutions with cubic-tetragonal interfaces were prepared by an urea hydrolysis method and a solvothermal method. Then they were used as the supports and Mn/Ce-Zr catalysts were prepared by impregnation method. The catalytic performance of the catalysts for toluene oxidation were evaluated by a steady-state measurement and compared with that of Mn/Ce-Zr-ss without the interfaces, in which the support was prepared by co-precipitation. The result was found that the catalyst interfaces apparently enhanced catalytic activity for toluene oxidation. The coexistence of cubic and tetragonal phases and their interfaces were confirmed by XRD and HRTEM. H2-TPR and XPS results indicated that the cubic-tetragonal interfaces led to stronger interaction between surface Mn and Ce species and higher concentration of lattice oxygen produced from the catalyst surface. DRIFT spectra revealed that the catalyst interface promoted the adsorption of toluene and the formation of key intermediates at low temperatures. These would be important factors that caused a higher activity of the catalyst with cubic-tetragonal interfaces. Moreover, the promoting role of the interfaces might be related to the morphology, surface area and interface components of Ce-Zr supports.