高比表面Ce_xZr_(1-x)O_2复合氧化物的制备及表征

Preparation and Characterization of High Specific Surface Area Ce_xZr_(1-x)O_2 Mixed Oxide

分别采用共沉淀法和阴离子表面活性剂模板法制备了CexZr1-xO2复合氧化物。采用XRD、AFM、FTIR以及N2吸附-脱附等方法对样品进行了表征。结果表明,共沉淀法合成的样品在500℃煅烧2h后,生成了立方相Ce0.75Zr0.25O2和四方相Ce0.5Zr0.5O2固溶体,比表面积为62.1m2·g-1,孔体积为0.097cm3·g-1;以阴离子表面活性剂十二烷基苯磺酸钠(SDBS)为模板剂,乙二胺为助模板剂合成的样品在500℃煅烧2h后,生成了纯四方相Ce0.5Zr0.5O2固溶体,比表面积为180m2·g-1,孔体积为0.182cm3·g-1。结果表明,以阴离子表面活性剂SDBS为模板剂,可以合成高比表面积且具有介孔结构的Ce0.5Zr0.5O2复合氧化物;加入乙二胺作为助模板剂可明显的提高比表面积和孔体积。

CexZr1-xO2 mixed oxides were synthesized by co-precipitation reaction and anionic surfactant-assisted route, respectively. XRD, AFM, FTIR and N2 adsorption-desorption have been used for structural characterizations. The results show that the product prepared by co-precipitation reaction consists of cubic Ce0.75Zr0.25O2 and tetragonal Ce0.5Zr0.5O2 after calcination under 500℃ for 2 h, the specific surface area and total pore volume are 95.1 m^2·g^-1 and 0.097 cm^3·g^-1, respectively; the product prepared by anionic surfactant-assisted route has a pure tetragonal phase Ce0.5Zr0.5O2 solid solution after calcination under 500 ℃ for 2 h, the specific surface area and total pore volume are 180 m^2·g^-1 and 0.182 cm^3·g^-1, respectively. The use of SDBS as template agent can successfully synthesize mesoporous Ce0.5Zr0.5O2 solid solution with high specific surface area and the use of ethylenediamine as assisted-template agent can improve specific surface area and total pore volume.