Preparation of high oxygen storage capacity and thermally stable ceria–zirconia solid solution

Abstract

Ceria–zirconia solid solution is a very important material in three-way catalysts for automotive emission control. High oxygen storage capacity (OSC) and thermally stable Ce_0.5Zr_0.5O₂ was prepared by a modified complexing–coprecipitation (CC) method, and its surface area reached 44 m² g⁻¹ after calcination at 1100 °C for 6 h. Based on the characterizations of its structural and physicochemical properties, it was found that Ce_0.5Zr_0.5O₂ prepared by the CC method existed as the t′′-phase with rich oxygen defects and surface Ce³⁺ and has a larger BET surface area, uniform particle and pore sizes, and excellent bulk oxygen migration and redox abilities than samples prepared by other methods. After being calcined at 1100 °C for 6 h, its surface area, OSC (and OSCC, oxygen storage capacity complete) and catalytic activity for the oxidation of CO were still the best among three Ce_0.5Zr_0.5O₂ solid solutions prepared by three methods whether it was used as the catalyst or as a support for a Pd catalyst, reflecting its good thermostability, although its particle and pore sizes were somewhat increased. This complexing–coprecipitation method can be used to prepare other high surface area and thermally stable inorganic materials.