Nanostructured Ce1−xZrxO2 solid solutions produced by mechanochemical processing

The nanostructured Ce1−xZrxO2 solid solutions (x ≤ 0.2) have been successfully synthesized from CeCl3–ZrCl4–NaOH mixtures by mechanochemical processing as a gradual transformation, involving in-situ CeO2 and amorphous ZrO2 formation as intermediates. Solid solutions type-Ce1−xZrxO2 along with NaCl as diluent were obtained at different milling times, with a final composition of Ce0.8Zr0.2O2 after 5 h and 15 h under high and low energetic milling conditions, respectively. The NaCl formed during the mechanochemical reaction, which is eliminated by washing after calcination of the as-milled sample, allows to obtain a Ce0.8Zr0.2O2 solid solution with high surface area and nanometric grains. The nanostructured Ce0.8Zr0.2O2 solid solution shows good thermal stability after prolonged heating at 600 °C. However, the addition of an extra amount of diluent during mechanochemical reaction evidences a detrimental effect, avoiding the formation of solid solution or deteriorating the textural/microstructuctural characteristics of the obtained Ce1−xZrxO2 solid solution. Removal of NaCl previous to calcination improves notably the textural/microstructural characteristics of the Ce0.8Zr0.2O2 solid solution.