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

The oxygen storage capacity (OSC) of CeO 2 –ZrO 2 solid solutions that were directly formed as nanocrystals by thermal hydrolysis of acidic aqueous solutions of (NH 4 ) 2 Ce(NO 3 ) 6 and ZrOCl 2 at 150°C increased from 94 μmol of O 2 /g for pure CeO 2 to >400 μmol of O 2 /g for compositions of CeO 2 /ZrO 2 with molar ratios (C/Z) from 74.1/25.9 to 41.7/58.3 (maximum value of 431 μmol O 2 /g was reached at the composition C/Z = 51.7/48.3) and then decreased with increased ZrO 2 content in the solid solutions. As compared with pure CeO 2 , the CeO 2 –ZrO 2 solid solutions that contained <84.8 mol% ZrO 2 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.