沉淀方法对铈锆铝复合氧化物结构和性能的影响  

Effect of Precipitation Method on Performance of CeO2-ZrO2-Al2O3 Composite Oxide

作　　者：杨黄根 晏全[1] 韦庆敏[1] 陈渊[1] 朱立刚[1] 覃利琴[1] 肖益鸿[2] Yang Huanggen;Yan Quan;Wei Qingmin;Chen Yuan;Zhu Ligang;Qin Liqin;Xiao Yihong(Guangxi Key Laboratory of Agricultural Resources Chemistry and Biotechnology,Yulin Normal University,Yulin 537000,China;National Engineering Research Center of Chemical Fertilizer Catalyst,Fuzhou University,Fuzhou 350002,China)

机构地区：[1]玉林师范学院广西农产资源化学与生物技术重点实验室,广西玉林537000 [2]福州大学化肥催化剂国家工程研究中心,福建福州350002

出　　处：《中国稀土学报》2020年第2期160-168,共9页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(21767029,51862034);广西自然科学基金项目(2017GXNSFAA198197);广西科技计划项目-重点研发计划项目(桂科AB18050004);玉林师范学院校级科研项目(2017YJKY24)资助。

摘　　要：采用共沉淀法(CZA)、沉淀悬浊液混合法(CZ+A)、分步沉淀法Ⅰ(CZ-A)和分步沉淀法Ⅱ(A-CZ)4种不同沉淀方法制备铈锆铝复合氧化物(Ce,Zr,Al摩尔比为1∶1∶2),利用X射线粉末衍射(XRD)等手段研究其结构及性能。结果表明:4种样品均只出现归属于Zr0.4Ce0.6O2立方相的特征衍射峰,其中CZA-1000的晶胞参数和晶粒尺寸明显更小;4种样品均具有介孔特征,比表面积较大,老化后只有CZA-1000仍呈现孔径单峰分布曲线,孔径分布最小且最窄;老化后CZA-1000的储氧量最大;CZA-1000还原峰主峰温度比其他3种老化样品的低23~30℃,CZA-1000体相氧的移动性能更强,而其他3种老化样品还原峰主峰温度更高,烧结更严重。研究发现,共沉淀法制备的CZA样品中铈锆和Al2O3粒子以纳米尺度均匀混合,相互之间有着更强的作用和更好的“扩散阻碍”效应,具有更好的结构、织构、储氧、还原和耐热性能。Ceria-zirconia-alumina composite oxides(the molar ratio of Ce,Zr and Al is 1∶1∶2)were prepared by the coprecipitation(CZA),mixing suspension of precipitates(CZ+A),stepwise precipitationⅠ(CZ-A)andⅡ(A-CZ)methods,respectively.The structure and performance of the composite oxides were studied by X-ray diffraction(XRD)and other means.The results showed that the characteristic diffraction peaks belonging to Zr0.4Ce0.6 O2 cubic phase only appeared in the four kinds of samples,among which the cell parameters and crystal size of CZA-1000 were significantly smaller;Four kinds of samples possessed mesoporous characteristics,larger specific surface area,and only CZA-1000 still showed unimodal distribution curve,narrow and the smallest pore size distribution.The oxygen storage capacity(OSC)of the aging CZA-1000 was the largest.The main peak temperature of the reduction peak of CZA-1000 was 23~30℃lower than that of the other three aging samples.The bulk phase oxygen of CZA-1000 has stronger mobile performance,while the main peak temperature of the reduction peak of the other three aging samples were higher and the sintering is more serious.It was found that the particles of cerium-zirconium and alumina in the CZA samples prepared by co-precipitation were evenly mixed at the nanoscale,with stronger interaction and better“diffusion obstruction”effect among each other,thus exhibiting better structure,texture,oxygen storage,reduction and heat resistance properties.

关 键 词：铈锆铝复合氧化物 沉淀方法 储氧性能 还原性能 

分 类 号：O643[理学—物理化学]