The synthesis of mesoporous Ce_1−x Zr _x O₂ by modified evaporation-induced self-assembly method

Mesoporous Ce_1−x Zr _x O₂ with high surface area was synthesized using a modified evaporation-induced self-assembly method that combined citric acid as complexing agent and cetyltrimethyl ammonium bromide as surfactant. The samples with different Ce/Zr molar ratio were characterized by thermogravimetry and differential thermal analysis, X-ray diffraction, transmission electron microscopy, selected area electron diffraction, Brunauer–Emmett–Teller (BET), and Barrett–Joyner–Halenda methods. It was found that when the Zr molar fraction was larger than 0.3, a mixture of cubic phase and tetragonal phase was formed. Ce_0.7Zr_0.3O₂ solid solution had the largest BET surface area (217 m² g⁻¹) and mesoporous structure. The catalytic performances of mesoporous Ce_1−x Zr _x O₂ for CO oxidation were examined. Mesoporous Ce_0.7Zr_0.3O₂ solid solution demonstrated the best catalytic activity due to the high surface area and an enhanced redox property caused by appropriate Zr⁴⁺ incorporation.