Oxygen Storage Capacity, Specific Surface Area, and Pore‐Size Distribution of Ceria–Zirconia Solid Solutions Directly Formed by Thermal Hydrolysis

Abstract

The oxygen storage capacity (OSC) of CeO2–ZrO2 solid solutions that were directly formed as nanocrystals by thermal hydrolysis of acidic aqueous solutions of (NH4)2Ce(NO3)6 and ZrOCl2 at 150°C increased from 94 μmol of O2/g for pure CeO2 to >400 μmol of O2/g for compositions of CeO2/ZrO2 with molar ratios (C/Z) from 74.1/25.9 to 41.7/58.3 (maximum value of 431 μmol O2/g was reached at the composition C/Z = 51.7/48.3) and then decreased with increased ZrO2 content in the solid solutions. As compared with pure CeO2, the CeO2–ZrO2 solid solutions that contained <84.8 mol% ZrO2 maintained high specific surface area and large pore volume with nanosized pores (pore size at maximum pore volume) <10 nm in diameter after heat treatment at 700°C.