Tailoring thermal stability of ceria-zirconia mixed oxide by doping of rare earth elements:From theory to experiment  

作　　者：Zheng Zhao Xiaowei Huang Yongqi Zhang Juanyu Yang Meisheng Cui Yongke Hou Zongyu Feng 

机构地区：[1]National Engineering Research Center for Rare Earth Materials,GRINM Group Corporation Limited,Beijing 100088,China [2]Griem Hi-tech Co.,Ltd.,Langfang 065000,China [3]Rare Earth Functional Materials(Xiong’an)Innovation Center Co.,Ltd.,Baoding 071700,China

出　　处：《Journal of Rare Earths》2022年第8期1272-1280,共9页稀土学报（英文版）

基　　金：Project supported by China Postdoctoral Science Foundation(2020M680616);Major State Research Development Program of Hebei province(20374202D)。

摘　　要：Ceria-zirconia mixed oxides(CZMO)are widely used in many important catalysis fields.However,pure CZMO is known to have poor thermal stability.In this paper,a strategy was proposed to design Ce_(0.475)Zr_(0.475)M_(0.05)O_(2)(M=La,Y,Pr,Nd,Pm,Sm,Eu,Gd,Tb,Er,Lu,and,Yb)oxide surface with high thermal stability by using first-principles molecular dynamics(FPMD)simulation and experiment method.Through the structure stability analysis at different temperatures,the surface energyγas a function of R_(ion)/D_(ave)is identified as a quantitative structure descriptor for analyzing the doping effect of rare earth(RE)elements on the thermal stability of Ce_(0.475)Zr_(0.475)M_(0.05)O_(2).By doping the suitable RE,γcan be adjusted to the optimal range to enhance the thermal stability of Ce_(0.475)Zr_(0.475)M_(0.05)O_(2).With this strategy,it can be predicted that the sequence of thermal stability improvement is Y>La>Gd>Nd>Pr>Pm>Sm>Eu>Tb>Er>Yb>Lu,which was further verified by our experiment results.After thermal treatment at 1100℃for 10 h,the specific surface area(SSA)of aged Y-CZ and La-CZ samples can reach 21.34 and 19.51 m~2/g,which is 63.02%and 49.04%higher than the CZMO sample without doping because the surface doping of Y and La is in favor of inhibiting the surface atoms thermal displacement.In a word,the strategy proposed in this work can be expected to provide a viable way for designing the highly efficient CZMO materials in extensive applications and promoting the usages of the high-abundance rare-earth elements Y and La.

关 键 词：Cerium zirconium oxides surface Thermal stability DOPING Structure descriptor Rare earth metals Theory and experiment 

分 类 号：TQ13[化学工程—无机化工]