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分别以ZrOCO3,ZrO(NO3)2和Zr(NO3)4为锆源采用双氧水氧化-共沉淀法合成了Ce0.45Zr0.45La0.1O1.95储氧材料,并用湿法浸渍法制备了Pd/Ce0.45Zr0.45La0.1O1.95三效催化剂,用X射线衍射、拉曼光谱、N2吸附、X射线光电子能谱、氢气程序升温还原和氧脉冲等技术对该催化剂进行了表征.结果表明,以ZrOCO3和ZrO(NO3)2为锆源时所制催化剂上只能检测到单一的CeO2-ZrO2立方相,而以Zr(NO3)4为锆源制备的催化剂经老化后却能检测到四方相;另外,在模拟汽车尾气组分和工作条件下考察了整体型Pd/Ce0.45Zr0.45La0.1O1.9催化剂的三效活性.结果表明,以ZrOCO3为前驱体制备的整体式Pd/Ce0.45Zr0.45La0.1O1.9催化剂对C3H8,CO和NO具有最佳的催化活性.认为ZrOCO3更有利于Zr4+和La3+进入CeO2晶格形成均一固溶体,从而提高催化剂的高温稳定性和氧化还原性能.
Ce0.45Zr0.45La0.1O1.95 oxygen storage materials were synthesized by hydrogen peroxide oxidation-coprecipitation method using ZrOCO3, ZrO (NO3) 2 and Zr (NO3) 4 as zirconium sources respectively. Pd / Ce0 .45Zr0.45La0.1O1.95 three-way catalyst, the catalyst was characterized by X-ray diffraction, Raman spectroscopy, N2 adsorption, X-ray photoelectron spectroscopy, hydrogen temperature programmed reduction and oxygen pulse.The results show that the ZrOCO3 and ZrO (NO3) 2 can only detect a single CeO2-ZrO2 cubic phase on the catalyst, while tetragonal phase can be detected on the catalyst prepared from Zr (NO3) 4 as zirconium source after aging. In addition, the three-way activity of the monolithic Pd / Ce0.45Zr0.45La0.1O1.9 catalyst was investigated under simulated vehicle exhaust components and operating conditions.The results show that the monolithic Pd / Ce0.45Zr0 catalyst prepared with ZrOCO3 as precursor .45La0.1O1.9catalyst has the best catalytic activity for C3H8, CO and NO.It is believed that ZrOCO3 is more conducive to Zr4 + and La3 + into the CeO2 lattice to form a uniform solid solution, thus improving the high temperature stability and redox performance of the catalyst.