Ce-Zr固溶体的纯度及其在三效催化剂中的作用

采用溶胶－凝胶法和有机溶剂分解法，制备了Ｃｅ－Ｚｒ固溶体。应用ＸＲＤ和ＬＲＳ谱测试，详细研究了经不同温度焙烧后固溶体的结构、晶相和热稳定性，并进行了储氧量、比表面积的测定和催化活性评价。结果表明，ＸＲＤ和ＬＲＳ相结合，可以较好地表征固溶体，并且储氧量高，但热稳定性较有机溶剂分解法制得的固溶体差；含富铈固溶体的三效催剂剂老化后的催化活性明显高于含纯ＣeＯ２的三效催化剂。

Phase Purity of CeO2-ZrO2 Solid Solutions and their Effects on Three-way Catalysts

A series of CeO 2 ZrO 2 and CeO 2 ZrO 2 La\-2O\-3 solid solutions were prepared by modified sol gel method and organic solvent decomposition method. The phase, structure and thermal stability of solid solutions were investigated by XRD and LRS at different calcining temperatures. The oxygen storage capacity(OSC), BET surface area and catalytic activity of these samples were also evaluated. A combined analysis of XRD and LRS can give precise information on the structure and phase purity of CeO 2 ZrO 2 solid solutions. It is shown that the product of modified sol gel method possesses higher OSC, purer fluorite cubic phase ,but lower thermal stability than that of organic solvent decomposition method. It is also shown that the light off temperatures of CO, NO and C 3H 6 for aged catalysts containing CZO or LCZO are much lower than that of containing CeO 2 in synthetic car exhaust.