沉淀过程pH值对铈锆复合氧化物结构与性能的影响

采用加热回流老化技术制备了系列组成为0.6CeO₂-0.4ZrO₂的铈锆复合氧化物，通过N₂物理吸附、Raman光谱、UV-Vis 漫反射光谱等方法对沉淀过程pH值对铈锆复合氧化物结构及储氧性能的影响进行了研究。结果表明，沉淀过程pH值不同，将导致铈锆复合氧化物的组成产生波动，进而影响样品的晶相组成、缺陷性质、结晶程度和孔结构性质。控制沉淀pH值为10.5～11.0，可消除Si的影响，改善铈锆复合氧化物的孔结构，提高相均匀性，提高缺陷浓度，降低结晶度，从而可提高样品的储氧性能。

Effects of pH Value during Synthesis on the Structure and Performance of Ceria Zirconia Mixed Oxides

Heating reflux aging technology was first applied to obtain a series of ceria zirconia mixed oxides composed of 0.6CeO2-0.4ZrO2.N2 physical adsorption,FT-Raman,and UV-Vis diffuse spectroscopy techniques were preformed to investigate the relationships between the structure and oxygen storage capacity of ceria zirconia mixed oxides prepared at different pH value of precipitation.The composition of ceria zirconia mixed oxides fluctuated with the pH value of precipitation,leading to the variation in phase ingredients,defects,crystallization and texture.Controlling the pH value of precipitation at 10.5-11.0 can avoid the introduction of Si,improve the texture,phase homogeneity and defects concentration,decrease the degree of crystallization,and increase the oxygen storage capacity.