Ce0.35Zr0.55La0.10O1.95对低贵金属Pt-Rh型三效催化剂性能的影响

采用共沉淀技术制备了Ce0.35Zr0.55La0.10O1.95固溶体, 其织构和结构性能以及氧化还原性能分别采用BET、XRD和程序升温(TP)技术进行了表征. 制备了低贵金属Pt-Rh型三效催化剂, 考察了Ce0.35Zr0.55La0.10O1.95对催化剂性能的影响. XRD和BET的结果表明, 经600 ℃焙烧5 h后, Ce0.35Zr0.55La0.10O1.95具有与Ce0.50Zr0.50O2相似的立方结构和高的比表面积；经1000 ℃焙烧5 h后, 仍能保持稳定的立方结构和47.25 m2•g−1的比表面积, 表现出优越的织构性能和高的热稳定性. H2-TPR和O2-TPO的结果表明, Ce0.35Zr0.55La0.10O1.95具有比Ce0.50Zr0.50O2更好的氧化还原性能. 和含Ce0.50Zr0.50O2的催化剂相比, 含Ce0.35Zr0.55La0.10O1.95的催化剂具有较宽的工作窗口, 优越的低温起燃性能, 较强的水气变换能力；催化剂经1000 ℃高温水热老化5 h后, 仍具有良好的催化活性, 表现出了优异的抗老化性能.

Influence of Ce0.35Zr0.55La0.10O1.95 Solid Solution on the Performance of Pt-Rh Three-way Catalysts

Ce0.35Zr0.55La0.10O1.95 solid solution was prepared by coprecipitation technique and characterized by specific surface area measurements (BET), X-ray diffraction (XRD), and temperature-programmed (TP) technique. Ce0.35Zr0.55La0.10O1.95 was used to prepare low Pt-Rh three-way catalyst (TWC) and its influence on the performance of TWC was investigated. The results showed that Ce0.35Zr0.55La0.10O1.95 had a cubic structure similar to Ce0.50Zr0.50O2 and high specific area after calcined at 600 ℃ for 5 h. Furthermore, after being aged at 1000 ℃ for 5 h, Ce0.35Zr0.55La0.10O1.95 still maintained a stable cubic structure and a specific surface area of 47.25 m2•g−1. The results of H2-TPR and O2-TPO indicated that Ce0.35Zr0.55La0.10O1.95 had good redox properties. The catalyst containing Ce0.35Zr0.55La0.10O1.95 possessed fairly wide range of three-way working-windows, good low temperature light-off properties, and better ability of water-gas shift. Being hydrothermal aged at 1000 ℃, the catalyst containing Ce0.35Zr0.55La0.10O1.95 still showed good catalytic activity in comparison with Ce0.50Zr0.50O2 TWC, which indicated that Ce0.35Zr0.55La0.10O1.95 improved the anti-aging properties of the catalyst.