氯化钠在直接热分解醋酸铈制备球形超细氧化铈粉末过程中的作用  

Effect of Sodium Chloride on Preparation of Spherical Ultrafine Ceria Powder by Direct Calcinating Cerium Acetate

作　　者：傅毛生[1,2] 李永绣[1] 危亮华[1] 

机构地区：[1]南昌大学稀土与微纳功能材料研究中心,江西南昌330047 [2]南昌航空大学环境与化学工程学院,江西南昌330063

出　　处：《稀土》2009年第3期1-5,共5页Chinese Rare Earths

基　　金：国家自然科学基金项目资助(201610002);江西省自然科学基金项目资助(02007;Q97001)

摘　　要：采用醋酸与碳酸铈反应获得醋酸铈前驱体,通过直接热分解制备氧化铈粉末,运用XRD、SEM、粒度测试仪和表面电位微电泳仪等表征手段,探讨氯化钠加入到醋酸铈前驱体中对氧化铈粉末形貌和粒度大小的影响。研究结果表明,氯化钠能促进氧化铈的晶化,而且煅烧温度对氧化铈的形貌和粒度大小有重要影响。当煅烧温度从600℃升高到1000℃,所得氧化铈粉末的中位粒径(D50)先增加后下降然后又增加,其中在800℃发生转折,其CeO2粉末的D50为1.57μm,粒子形貌为球状而且大小均匀,晶粒间只存在轻度团聚;当煅烧温度高于800℃,熔融氯化钠加速晶粒长大,粉末粒度增加较明显;而无氯化钠参与的醋酸铈前驱体在800℃热分解得到的CeO2粉末形貌各异而且大小不均匀,存在明显的局部烧结长大和粒子团聚现象,其D50为1.75μm。运用盐助机理模型对氯化钠在直接热分解醋酸铈前驱体制备氧化铈过程中的作用进行探讨。Cerium acetate precursor was prepared by liquid - phase reaction using cerium carbonate and acetic acid as raw materials, which was calcinated to synthesize ceria powders. The effects of sodium chloride on the morphology and granularity of as - synthesized ceria powders were investigated by XPtD, SEM, particle size analyzer and zeta potential analysis. The results show that the addition of sodium chloride in the cerium acetate precursor promotes the crystallinity of ceria, and calcination temperature plays a great importance role in the morphology and granularity of ceria. With increasing of calcination temperature from 600℃to 1000℃ ,the median particle sizes （D50） increased firstly and then decreased and finally increased. At the turning point of 800℃ ,assynthesized ceria had the minimum 1950 of 1.57μm and had spheroidal and uniformed particle shape, some of these nanograde particles were just loosely and slighdy agglomerated together. When the calcination temperature is over 800℃, molten sodium chloride promoted rapid growth of ceria grains and at the same time the granularity of as - synthesized ceria increased greatly. However, ceria powder synthesized by heating the cerium acetate precursor without the help of sodium chloride at 800℃ had irregular shape and uneven particle size,and exhibited greatly aggregated and partial sintering,D50 of which was 1.75tan.The effect of sodium chloride on preparation of ceria powder by calcinating the cerium acetate was explained by a salt- assisted mechanism scheme.

关 键 词：氯化钠 粒度 氧化铈 XRD 盐助机理 

分 类 号：O614.33[理学—无机化学]