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制备了不同BaO含量的CeO2-ZrO2储氧材料,并以此材料为载体浸渍H2PdCl6制得三效催化剂。结果表明,不论新鲜还是1000℃老化状态下,以10%BaO添加CeO2-ZrO2储氧材料制备的Pd三效催化剂活性最佳,起燃和完全转化温度最低。XPS结果证实,10%BaO添加,通过稳定PdO活性组分并改变其电子环境使得催化剂有最佳活性。而随着BaO含量持续增加,Pd活性组分相对处于较氧化状态。储氧量、低温N2吸附-脱附测试以及XRD测试结果均表明10%BaO添加的材料储氧量,比表面积以及孔容均最大,而且有适应三效催化的孔径。这些结果均有助于以其制备的Pd三效催化剂获得更好的活性以及热稳定性。
CeO2-ZrO2 oxygen storage materials with different contents of BaO were prepared, and three-way catalysts were prepared by impregnating H2PdCl6 with this material. The results showed that the Pd three-way catalyst prepared by adding CeO2-ZrO2 oxygen storage material with 10% BaO had the best activity and the lowest ignition and complete conversion temperature, both fresh and 1000 ℃. The XPS results confirmed that the addition of 10% BaO gave the best catalyst activity by stabilizing the PdO active component and changing its electronic environment. With the continuous increase of BaO content, Pd active components are relatively oxidized. The oxygen storage capacity, low temperature N2 adsorption-desorption test and XRD test results show that the oxygen storage capacity, specific surface area and pore volume of the 10% BaO-added material are the largest, and have the pore size suitable for the three-way catalysis. These results all help to obtain better activity and thermal stability of the Pd three-way catalyst prepared by it.