Nanostructured Ce1-xZrxO2 Solid Solutions Produced by Mechanochemical Processing

Abstract

The nanostructured Ce1xZrxO2solid solutions (x0.2) have been successfully synthesized from CeCl3-ZrCl4-NaOH mixtures by mechanochemical processing as a gradual transformation, involvingin-situ CeO2and amorphous ZrO2formation as intermediates. Solid solutions type-Ce1xZrxO2along with NaCl as diluent were obtained at different milling times, with afinal composition of Ce0.8Zr0.2O2after 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 Ce0.8Zr0.2O2solid solution with high surface area and nanometric grains. The nanostructured Ce0.8Zr0.2O2solid 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 Ce1xZrxO2solid solution. Removal of NaCl previous to calcination improves notably the textural/microstructural characteristics of the Ce0.8Zr0.2O2solid solution.