多元醇法制备条件对介孔Ce_(0.5)Zr_(0.5)O_2复合氧化物性能的影响

Influence of Polyol Method Preparation Conditions on the Performances of Mesoporous Ce_(0.5)Zr_(0.5)O_2 Mixed Oxide

采用多元醇法合成了一系列具有立方萤石结构的介孔Ce0.5Zr0.5O2(m-Ce0.5Zr0.5O2)复合氧化物,考察了前驱物和PVP浓度、反应时间、焙烧温度和时间等条件对m-Ce0.5Zr0.5O2复合氧化物性能的影响,并运用XRD、Raman、BET、FT-IR和TG等手段对样品进行了表征。结果表明,制备条件对m-Ce0.5Zr0.5O2复合氧化物的性能具有较大的影响,在前驱物和PVP浓度为0.04 M和0.16 M、反应时间7 h、焙烧温度和时间为673 K和4 h时,所制m-Ce0.5Zr0.5O2的性能最好,其比表面积、孔容和平均孔径分别为181 m2.g-1、0.282 cm3.g-1和3.75 nm。活性的测定结果表明,富氢条件下CuO/m-Ce0.5Zr0.5O2催化剂的CO氧化活性比CuO/cp-Ce0.5Zr0.5O2催化剂有较大幅度的提高.

Cubic fluorite-structured mesoporous Ce0.5Zr0.5O2（ m-Ce0.5Zr0.5O2） were synthesized via polyol method. The effects of preparation conditions, such as cerium and zirconium precursor and PVP concentration, reaction time, calcination temperature and time, on properties of m-Ce0.5Zr0.5O2 were investigated. The prepared samples were characterized by XRD, Raman, BET, FT-IR and TG. The preparation conditions on the performance of m-Ce0.5Zr0.5O2 mixed oxide have obviously effect. The specific surface area, pore volumn and average pore diameter of prepared sample are 181 m^2/g, 0. 282 cm^3·g^-1 and 3.75 nm , respectively, under the condition as： cerium and zirconium precursor concentration 0. 04M, PVP concentration 0. 16M, reaction time 7 h, calcination temperature 673K and calcination time 4 h. The activity of CuO/m-Ce0.5Zr0.5O2 is higer than that of CuO/cp-Ce0.5Zr0.5O2 catalyst for CO oxidation in H2-rieh gas.