Bimodal mesoporous CeO2–ZrO2-based materials prepared by PMMA nanosphere assisted co-precipitation and its thermal stability

Abstract

Bimodal mesoporous CeO2–ZrO2-based materials (CZP) are designed and prepared for high specific surface area and thermal stability. CZP is prepared by co-precipitation method and with the help of poly(methyl methacrylate) (PMMA) nanospheres. Its specific surface area reaches 93.8 m2/g higher than 54.8 m2/g of the unimodal mesoporous sample prepared without PMMA nanospheres (CZ). The pores of CZP are in the range of 2–100 nm and concentrate at 4 nm and 14 nm. CZ has narrowly distributed pores ranging from 2 nm to 8 nm. PMMA nanospheres have little effect on the crystal structure of the CeO2–ZrO2-based materials. Compared to CZ, CZP shows higher thermal stability. The specific surface area of CZP is higher than that of CZ at 800 °C. At 1000 °C, CZP is sintered to sponge-like morphology with pores over 100 nm, while CZ is sintered to dense solid granular morphology. The influence of PMMA nanospheres on oxygen storage capacity (OSC) and redox properties is in line with the changes in specific surface area. In addition, 1000 °C aged CZP presents better three-way catalysts (TWC) performance compared to CZ because of the porous sponge-like morphology of CZP.