Effect of carbonization temperature on the textural properties of Ce0.8Zr0.2O2 solid solution by an improved citrate sol–gel method

Abstract

Abstract Ce 0.8 Zr 0.2 O 2 solid solutions were prepared via an improved citrate sol–gel method, in which a carbonization pretreatment in N 2 atmosphere at a high temperature was employed prior to the calcination of the citrate precursor in air atmosphere. The effect of carbonization temperature on the textural properties of Ce 0.8 Zr 0.2 O 2 solid solutions has been investigated, using TG–DSC, Raman, XRD, TEM, SEM and BET techniques. With low carbonization temperature, the Ce 0.8 Zr 0.2 O 2 oxides in intermediate carbonized mixtures remained in amorphous state, which could eventually agglomerate to large particles with low surface area after subsequent calcination in air atmosphere. In comparison, with high carbonization temperature, thermodynamic force drove Ce 0.8 Zr 0.2 O 2 oxides to be crystallized into large particles, which would not agglomerate further in oxidation step (carbon removal), thus leading to a material with high surface area and porous structure.