Effects of ammonia concentration in hydrothermal treatment on structure and redox properties of cerium zirconium solid solution

• 作者: Yunhan Zhang Meisheng Cui Hao Wang Zheng Zhao Liangshi Wang Yongke Hou
• 来源期刊: 稀土学报（英文版）
• 年，卷（期）: 2021,（4）
• 所属期刊栏目: RARE EARTH CATALYSIS
• 页码范围: 419-426
• 页数: 8页
• 语种: 英文

摘要

Cerium zirconium solid solution is a key washcoat material for automotive three-way catalysts(TWCs).However,improving the redox ability and high temperature thermal stability of cerium zirconium solid solution is still a challenge.In this paper,the cerium zirconium solid solution was prepared by a coprecipitation-hydrothermal method,and the effects of the ammonia concentration on their structures and redox properties were investigated.The results show that when the ammonia concentration is 0.8 mol/L,the aged sample(1100 ℃/10 h)of cerium zirconium solid solution has the highest specific surface area of 23.01 m2/g.Additionally,the increase of ammonia concentration improves the uniformity of phase compositions and increases the oxygen vacancies.When the ammonia concentration reaches 0.4 mol/L,the cerium zirconium solid solution exhibits the best redox activity,with the lowest reduction temperature of 565 ℃.Therefore,increasing ammonia concentration in the hydrothermal treatment is beneficial to the thermal stability and redox performance of cerium zirconium solid solution.