Ce0．67Zr0．33O2材料的制备和表征及其负载单Pd三效催化剂的性能

Preparation and Characterization of Ce_(0.67)Zr_(0.33)O_2 and the Activity of Its Supported Only-Pd Three-Way Catalysts

采用共沉淀法、均匀沉淀法、微乳法和水热法四种方法制备了铈锆固溶体(CZ),对其进行了X射线衍射和N2吸附脱附分析.以CZ为载体制备了负载单Pd三效催化剂,并对催化剂进行了氧化还原性能测试.结果表明,制备方法对CZ载体的物理、化学性能有显著的影响,而其负载单Pd催化剂的催化活性与CZ载体比表面积的大小没有明显的对应关系.采用共沉淀法制备的CZ载体具有相对良好的热稳定性以及储放氧能力,其负载单Pd催化剂在老化前后表面PdO物种有良好的还原性能,并表现出优异的三效催化性能.

Ce0.67Zr0.33O2 （CZ） was prepared by the co-precipitation method, hydrothermal method, homogeneous precipitation method, and microemulsion method and characterized by X-ray diffraction and N2 adsorption-desorption. Only-Pd/CZ catalysts were prepared and studied by temperature-programmed reduction and activity tests. The results showed that preparation methods have great effect on the support properties, and there is no direct relationship between catalytic activity and support surface area. The CZ support prepared by the co-precipitation method showed relatively good thermal stability and oxygen storage property. The PdO species on CZ prepared by co-precipitation exhibited high reducibility before and after aging. The only-Pd catalysts have excellent three-way catalytic activity.