储氧材料Ce0.6Zr0.4-xPrxO2-δ的性能及在三效催化剂中的应用

采用溶胶-凝胶法制备了系列三效催化剂储氧材料Ce0.6Zr0.4-xPrxO2-δ（x=0．05，0．10，0．15）。X射线衍射证实形成的固溶体为萤石型立方相结构；BET比表面积分析表明，随着Pr的掺杂量由x=0．05递增到工=0．15，在650℃焙烧的样品其比表面积由66．5增加到79.9m^2／g，而未掺杂样品Ce0．6Zr0.4O2的比表面积为65．1m^2，g；粒度分布及透射电镜分析发现，制备的固溶体在水相中存在着团聚现象。应用在含有Pt，Rh和Pd的三效催化剂的制备。催化活性测试表明，在铈锆氧化物储氧材料中掺杂少量Pr，可降低三效催化剂对CO、C3H6和NO的起燃温度。不论是在富燃区还是在贫燃区，所有掺杂Pr的三效催化剂对各气体的催化转化率均高于未掺杂Pr的三效催化剂。

Surface and Texture Properties of Tb-Doped Ceria-Zirconia Solid Solution Prepared by Sol-Gel Method

The three-way catalysts （TWCs） promoters Ce0.6Zr0.4- x TbxO2-y were prepared by sol-gel method. BET surface areas analysis indicated that an increase of the dopant Tb content from x = 0.05 to x = 0.15 favors an increase of surface area from 66.8 to 80.4 m^2· g^-1 compared with the undoped sample Ce0 .6oZr0.40O2 65.1 m^2·g^- 1 after calcination at 650℃. Transmission electron microscopy （TEM） observation indicated that the doped samples have a higher thermal stability. The XRD and Raman spectra confirmed that the Ce0.6Zr0.4-xTbxO2-y cubic solid solution is formed. XPS analysis revealed that Ce and Tb mainly existed in the form of Ce^4＋ and Tb^3 ＋ , and Zr existed in the form of Zr^4＋ on the surface of the samples. The doped samples were homogenous in composition ; the introduction of Tb into the CeO2-ZrO2 promoters resuited in the formation of a solid solution, and the concentration of surface lattice oxygen was increased.

镨改性铈锆氧化物固溶体的制备与表征

采用溶胶-凝胶法制备了不同比例的Pr掺杂铈锆氧化物固溶体Ce0.6Zr0.4-xPrxO2-y(x=0.05,0.10,0.15)。X射线衍射证实形成的固溶体为萤石型立方相结构;BET比表面积分析表明,随着Pr的掺杂量由x=0.05递增到x=0.15,在650℃焙烧的样品其比表面积由66.5m2.g-1增加到79.9m2.g-1,而未掺杂样品Ce0.6Zr0.4O2的比表面积为65.1 m2.g-1;粒度分布及透射电镜分析发现,制备的固溶体在水相中存在着团聚现象。应用在含有Pt,Rh和Pd的三效催化剂的制备。催化活性测试表明,在铈锆氧化物储氧材料中掺杂少量Pr,可降低三效催化剂对CO、C3H6和NO的起燃温度。不论是在富燃区还是在贫燃区,所有掺杂Pr的三效催化剂对各气体的催化转化率均高于未掺杂Pr的三效催化剂。