Synthesis of ultrafine ceria powders by mechanochemical processing

The synthesis of ultrafine cerium dioxide (CeO2) powders via mechanochemical reaction and subsequent calcination was studied. Anhydrous CeCl3 and NaOH powders, along with NaCl diluent, were mechanically milled. A solid-state displacement reaction-CeCl3 + 3NaOH --> Ce(OH)(3) + 3NaCl-was induced during milling in a steady-state manner. Calcination of the as-milled powder in air at 500 degreesC resulted in the formation of CeO2 nanoparticles in the NaCl matrix. A simple washing process to remove the NaCI yielded CeO2 particles similar to 10 nm in size. The particle size was controlled in the range of similar to 10-500 nm by changing the calcination temperature.