摘要
采用共沉淀法制备了不同铈锆比的ZrxCe1-xO2(x=0,0.1,0.3,0.5,0.7,0.9,1.0)固溶体.利用热分析方法研究了Zrx(OH)4x.Ce1-x(OH)4(1-x)体系的热分解过程,并运用XRD对其热分解产物进行了表征.实验表明Zrx(OH)4x.Ce1-x(OH)4(1-x)在空气中的热分解是一步完成的,随着锆含量的增加分解温度逐渐提高.应用微分法和积分法相结合对该分解过程的分解机理进行了推测,得出了一系列分解反应的表观活化能E和指前因子A.发现其热分解反应遵循Zhuralev-Lesokin-Tempelman三维扩散机理,其动力学方程为:f(α)=3/2(1-α)4/3[(1-α)-1/3-1]-1;g(α)=[(1-α)-1/3-1]2,其表观活化能大小与样品中的锆含量有关.
Zr, Ce1-xO2 (x = 0, 0.1,0.3,0.5,0.7, 0.9, 1.0) solid solutions are prepared by co-precipitation method. TG-DTG-DTA thermal analysis technique is employed to study the thermal decomposition processes of Zrx (OH)4x·Ce1-x, (OH)4(1-x) precursors in air. The thermal decomposition products are confirmed by XRD. It is found that each thermal deamposition process is completed through one step and the decomposition temperature rises with the addition of Zr content. The decomposition mechanism and non-isothermal kinetic data are analyzed by Achar method and Coats-Redfern method. The possible mechanism follows Zhuralev-Lesokin-Tempelman three-dimension diffuse and the kinetic equation is : f(α)=3/2(1-α)^4/3[(1-α)^-1/3-1]^-1;g(α)=[(1-α)^-1/3-1]^2. The kinetic data ( activation energy and pre-exponential factor) possibly relate to Zr content in samples.
出处
《烟台大学学报(自然科学与工程版)》
CAS
2007年第4期254-258,共5页
Journal of Yantai University(Natural Science and Engineering Edition)
基金
国家自然科学基金资助项目(20473070)
山东省自然科学基金资助项目(Y2004B07)