CeO_2-ZrO_2固相溶液的制备和贮氧能力的研究  

STUDY ON PREPARATION AND OXYGEN STORAGE CAPACITY OF CeO_2-ZrO_2 SOLID SOLUTION

作　　者：袁文辉[1] 罗仡科[1] 

机构地区：[1]华南理工大学化工学院广东省绿色化学品技术重点实验室,广州510640

出　　处：《离子交换与吸附》2007年第4期322-329,共8页Ion Exchange and Adsorption

基　　金：教育部传热与节能重点实验室开发基金;广东省自然科学基金(04020126)资助

摘　　要：二氧化铈(CeO2)是优良的催化剂和催化剂促进剂,通过引入二氧化锆(ZrO2)可以提高其热稳定性及贮氧能力。研究以硝酸铈(IV)和氯氧锆为原料,用均相沉淀法制备CeO2-ZrO2固相溶液。用X光衍射(XRD)、差热-热重分析(DSC-TGA)、BET测定法和贮氧能力测定法对制备的CeO2-ZrO2进行了表征。BET测定制备的样品比表面积可达114m2/g;XRD结果表明,均相沉淀法制备样品具有萤石结构,Ce/Zr为3:1,450℃时即可制备出Ce0.75Zr0.25O2,800℃时,相结构稳定,TGA-DSC热分析没有出现热峰,说明样品热稳定性优良;通过100℃、200℃、400℃和800℃的氧贮存能力测定,实验结果表明,CeO2-ZrO2固体溶液的氧贮存能力随温度的升高而降低,在高温下的氧贮存能力随Zr含量的增加而增大,ZrO2的引入不但改进了CeO2的热稳定性,而且提高CeO2样品高温下的氧贮存能力。CeO2 as catalyst and catalyst promoter has attracted more interests. The thermal stability and oxygen storage capacity of CeO2 can be improved by ZrO2 doping. CeO2-ZrO2 solid solutions have prepared by homogenous precipitation with Ce（NOa）4 and ZrOC12 used as starting materials. XRD, DSC-TGA, BET and oxygen storage capacity test are used to characterize crystal structure and OSC of CeO2-ZrO2. BET measurement results show that the specific surface area of sample can reach 114m^2/g. XRD results shows that CeO2-ZrO2 solid solution obtained by homogenous precipitate is fluorite structured. When Ce/Zr is 3：1, Ce0.75Zr0.25O2 can be obtained at 45∩℃. Stable structured CeO2-ZrO2can be prepared at 800℃.No thermal peak seen in the TGA-DSC shows that CeO2-ZrO2 is thermal stable. Oxygen storage capacity results of samples obtained at 100℃, 200℃, 400℃ and 800℃ show that OSC of CeO2-ZrO2 increases with the increase of zirconium content, and decreases with increasing temperature. It is shown that both oxygen storage capacity and heat stability of CeO2 can be improved by ZrO2 doping.

关 键 词：CEO2-ZRO2 均相沉淀法 结构表征 贮氧能力 

分 类 号：O611.62[理学—无机化学]