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 

机构地区：[1]National Engineering Research Center for Rare Earth Materials.GRINM Group Corporation Limited.Beijing 100088,China [2]Grirem Advanced Materials Co.,Ltd.,Beijing 100088,China [3]General Research Institute for Nonferrous Metals,Beijing 100088,China [4]Rare Earth Functional Materials Innovation Center(Xiongan)Co.,Ltd.,Xiongan 071000,China

出　　处：《Journal of Rare Earths》2021年第4期419-426,共8页稀土学报（英文版）

基　　金：Project supported by the National Key Research and Development Program(2017YFC0211002).

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 m^(2)/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.

关 键 词：Ammonia concentration Hydrothermal treatment Cerium zirconium solid solution Thermal stability Redox Rare earths 

分 类 号：TQ426[化学工程]