Synthesis of Ultrafine Ceria Powders by Mechanochemical Processing

The synthesis of ultrafine cerium dioxide (CeO 2 ) powders via mechanochemical reaction and subsequent calcination was studied. Anhydrous CeCl 3 and NaOH powders, along with NaCl diluent, were mechanically milled. A solid‐state displacement reaction—CeCl 3 + 3NaOH → Ce(OH) 3 + 3NaCl—was induced during milling in a steady‐state manner. Calcination of the as‐milled powder in air at 500°C resulted in the formation of CeO 2 nanoparticles in the NaCl matrix. A simple washing process to remove the NaCl yielded CeO 2 particles ∼10 nm in size. The particle size was controlled in the range of ∼10–500 nm by changing the calcination temperature.