影响纳米CeO_2沉淀法合成的工艺因素研究  

Effect Factors on Synthesis of CeO_2 Nanoparticles by Precipitation Method

作　　者：邱冠周[1] 宋晓岚[1] 曲鹏[1] 杨振华[1] 吴雪兰[1] 王海波[1] 

机构地区：[1]中南大学资源加工与生物工程学院无机材料系,湖南长沙410083

出　　处：《中国稀土学报》2005年第3期321-327,共7页Journal of the Chinese Society of Rare Earths

基　　金：湖南省自然科学基金资助项目(03JJY3015);国家自然科学基金资助项目(59925412)

摘　　要：以Ce(NO3)3·6H2O为铈源, (NH4)2CO3·H2O为沉淀剂, 加入少量表面活性剂作分散剂, 采用液相沉淀法成功合成了纳米CeO2. 研究了反应温度、反应时间、搅拌速率、表面活性剂种类及用量、焙烧温度和焙烧时间等因素对纳米CeO2晶粒尺寸和相对密度的影响, 得出优化工艺条件, 通过XRD, DTA/TG, TEM, BET比表面积、 N2等温吸附与脱附、 BJH脱附孔径分布及杂质含量分析等方法对合成产品性能进行了表征. 结果表明: 采用浓度为0.1 mol·L-1的(NH4)2CO3·H2O溶液快速倒入浓度为0.1 mol·L-1 的Ce(NO3)3·6H2O溶液中以化学计量比进行反应, 同时加入0.4% (质量分数) PEG4000, 反应时间为10 min, 反应温度为40 ℃, 搅拌速率为800 r·min-1, 经水洗、醇洗、脱水和真空干燥后所得的前驱体于300 ℃的空气中焙烧1 h, 该条件下合成的CeO2属于立方晶系, 空间群为Fm3m, 原生晶粒粒径为5 nm左右, 颗粒粒径为20 nm以下, 比表面积达140.61 m2·g-1, 孔径分布为5～15 nm, 孔径峰值为9.3 nm, 纯度≥99.97%.High pure activing CeO2 nanoparticles were successfully synthesized by chemical precipitation method. The effect factors such as reaction temperature, reaction time, mechanical stirring velocity, surfactant, calcinations temperature and calcinations time on grain size or relative density of CeO2 nanoparticles are investigated, and optimizing conditions were obtained. The properties of CeO2 nanoparticles were characterized by XRD, DTA/TG, TEM, BET surface area, N2 isotherm adsorption and desorption, BJH desorption pore size distribution and impurity content analysis. The results show that CeO2 nanoparticles are formed entirely by heating the precursor Ce2(CO3)3 ·H2O, after water washing, ethanol washing, dehydrating and drying, at 300 ℃ for 1 h obtained from reaction of 0.1 mol·L -1 (NH4)2CO3·H2O solution as precipitator and 0.1 mol·L -1 Ce(NO3)3·6H2O according to chemical measure ratio with 0.4% PEG4000 as surfactant. The optimizing conditions of reaction are 40 ℃ reaction temperature, 10 min reaction time, 800 r·min -1 mechanical stirring velocity. The properties of CeO2 nanoparticles are of cubic crystal system and space group, about 5 nm average grain size, about 20 nm particle size, 140.61 m2·g -1 BET surface area, 5～15 nm pore size distribution and 9.3 nm maximum pore size, not lower than 99.97% purity.

关 键 词：纳米CEO2 沉淀法 影响因素 稀土 

分 类 号：O614.33[理学—无机化学] TB383[理学—化学]