焙烧条件对Ce离子价态影响的XPS研究  

XPS Study on the Influence of Calcination Conditions to Cerium Ion Valence

作　　者：梅燕[1] 闫建平[1] 聂祚仁[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124

出　　处：《光谱学与光谱分析》2010年第1期270-273,共4页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(50525413);北京工业大学博士科研启动基金项目(X0009311200802)资助

摘　　要：在均相沉淀法制备含铈化合物的过程中,利用XRD和IR尤其是XPS研究了含Ce化合物在不同焙烧温度条件下产物的结构、铈离子的价态变化、化合物表面性质及其内核电子构型。XRD结果表明,焙烧温度的不同可产生不同的铈基化合物,导致产物中Ce离子价态的变化,IR结果也证实了这一点。单纯均相沉淀法得到的产物为三价的斜方晶系的单晶Ce_2O(CO_3)_2·H_2O(Ⅲ)微粒;将三价的Ce_2O(CO_3)_2·H_2O加热到200℃,产物转化成高价态六价化合物CeO(CO_3)_2·H_2O(Ⅵ);加热温度再升高到250℃,产物转化为稳定的四价化合物CeO_2(Ⅳ)。XPS通过对3种不同价态化合物的O(1s),Ce(3d),Ce(4d)峰进行精细扫描,研究了产物的表面性质及其内部电子构型,比较结果证实了不同价态铈化合物的形成是由于内核价电子构型的差异引起的。For the system of Ce（NO3 ）2· 6H2O and urea solution during homogeneous precipitation method, X-ray diffraction （XRD）, infrared spectrum （IR） and especially X-ray photoelectron spectroscopy （XPS） were used to study and characterize the product structure, variety of cerium ion valence, compound surface character and kernel electronic configurations. The results of XRD and IR showed that calcination temperature had a great effect on the cerium ion valence. The products are orthorhombie Ce2 O（CO3 ）2 · H2O with valence Ⅲ by using homogeneous precipitation method directly. When heated from the temperature 200 ℃ to 250 ℃, the product of CEO（CO3）2 · H2O with valence Ⅵ was finally changed into stable CeO2 with valence Ⅳ. XPS was used to study the surface character and kernel electronic configurations of the three different compounds through fine scanning of O（1s）, Ce（3d） and Ce（4d） apices, and the results approved that the compounds with different valences are caused by the different valence electronic configurations of the products.

关 键 词：焙烧 铈离子价态 X射线光电子能谱(XPS) 

分 类 号：O614.3[理学—无机化学] O643.3[理学—化学]