Precursor effects in preparation CeO2-ZrO2-Al2O3 materials

Abstract

In this work, a series of CeO2-ZrO2-Al2O3 (CZA) materials were prepared by deposition-precipitation method, among that, the Al(NO3)3.9H2O, pseudo-boehmite and Al2O3 were worked as aluminum precursor, respectively. The results of N2 adsorption-desorption, H2-TPR, TEM-mapping, XRD, and XPS show that the aluminum precursor has an impact on interaction between Al2O3 and CeO2-ZrO2 (CZ), resulting in differences in textural, structural and reduction properties of CZA materials. The CZA material from Al(NO3)3.9H2O displays superior textural properties and thermal stability due to the uniform distribution of Ce, Zr and Al. However, its reducing performance is limited own to stronger interactions among the components. On the contrary, the interaction between ZrO2 and Al2O3 is weaker when aluminum precursor is pseudo-boehmite or Al2O3, it facilitates the improvement of the reducing properties, but the obtained CZA material with a poor thermal stability due to the “mechanical-like” mixing mode between Ce-Zr and Al. Especially, the CZA deriving from pseudo-boehmite, possesses more oxygen vacancies and Oβ after aging, so it displays better redox performance.