用正电子湮没研究Fe(Ⅲ)在γ-Al_2O_3载体中的自发扩散  

Spontaneous Dispersion of the Fe(Ⅲ) Salt into γ-Al_2O_3 Studied by Positron Annihilation

作　　者：朱俊[1] 张奇林[1] 李威[1] 罗锡辉[2] 

机构地区：[1]武汉大学物理科学与技术学院,湖北武汉430072 [2]抚顺石油化工研究院,辽宁抚顺113001

出　　处：《武汉大学学报（理学版）》2009年第4期447-450,共4页Journal of Wuhan University:Natural Science Edition

基　　金：国家自然科学基金资助项目(10675093)

摘　　要：采用机械混合的办法，将Fe（NO3）3·9H2O加载于多孔γ-Al2O3载体，并利用正电子湮没寿命谱学研究其自发扩散过程．实验测量了不同Fe（Ⅲ）质量分数的样品（1．3％～4．2％）在不同温度（100～600℃）烘烤后的正电子寿命谱．实验结果表明，未烘烤时，Fe（Ⅲ）主要分布在γ-Al2O3载体颗粒表面；烘烤后，Fe（Ⅲ）向γ-Al2O3载体颗粒的内部二次孔扩散，并首先占据活性中心的位置．同时，部分Fe（Ⅲ）扩散到γ-Al2O3载体的微孔中．在烘烤温度大于400℃时，能使Fe（Ⅲ）和γ-Al2O3载体中均匀分布．The samples were prepared from mechanical mixtures of Fe（NO3 ）3· 9H2O with γ-Al2O3, and then the spontaneous dispersions of the Fe（ Ⅲ ） inlo the γ-Al2O3support were studied by positron annihilation spectroscopy. We measured the positron annihilation lifetime spectra of the samples with different Fe（Ⅲ） （1.3%-4.2%） contents heated at different temperatures 100-600 ℃. h showed that with no heating, most of Fe（Ⅲ） was mainly located at the surface of the support. When the samples were heated, Fe（ Ⅲ ） would go to inner secondary pores and take the active-centres first, some went to the mircopores. When heated over 400℃ , Fe（ Ⅲ ） could disperse evenly.

关 键 词：正电子湮没谱学 铁离子 Γ-AL2O3 自发扩散 

分 类 号：TQ426.61[化学工程]