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。
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 eeria zireonia mixed oxides prepared at different pH value of precipitation. The composition of eeria zireonia 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.