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以浸渍法制备了α Al2 O3 负载的含钯La0 9Sr0 1CoO3 δ钙钛矿样品 ,探讨了水热老化对样品催化CO NO反应性能的影响 ,并以XRD ,TPR和XPS等对样品在水热老化前后的结构进行了表征 .结果表明 ,钯的引入方式直接影响样品的水热性能 .掺钯样品 (LaSrCoPd)具有良好的水热性能 ,经水热老化后 ,其催化活性显著提高 ,显示出最好的催化性能 ;样品中钯离子位于钙钛矿晶相内 ,形成α Al2 O3 负载的La0 9Sr0 1Co0 95Pd0 0 5O3 δ.La0 9Sr0 1CoO3 δ/α Al2 O3 负载钯的样品 (Pd/LaSrCo)具有最高的初活性 ,但经水热老化后 ,其催化活性明显降低 .在水热老化过程中 ,La0 9Sr0 1CoO3 δ钙钛矿的结构稳定 ,但含钯钙钛矿晶相中的钯离子迁移聚集成独立的PdO颗粒 ,较小的PdO颗粒聚集成较大的颗粒 .水热老化后 ,Pd/LaSrCo样品表面裸露的钯原子数目减少 ,导致其催化活性降低 ;而LaSrCoPd样品表面裸露的钯原子数目增多 ,导致其催化活性升高 .
An α Al 2 O 3 -supported La0 9Sr0 1CoO3 δ perovskite was prepared by impregnation method. The effects of hydrothermal aging on the catalytic CO NO reactivity of the sample were investigated. The effects of hydrothermal aging on the samples were investigated by XRD, TPR and XPS. The results show that the introduction of palladium directly affects the hydrothermal performance of the sample.The palladium-doped sample (LaSrCoPd) has good hydrothermal properties, and its catalytic activity is significantly increased after hydrothermal aging (Pd / LaSrCo) was the highest in the samples with the Pd ions in the perovskite crystal phase and forming the α Al 2 O 3 supported La0 9Sr0 1Co0 95Pd0 0 5O3 δ. La0 9Sr0 1CoO3 δ / α Al2 O3 , But its catalytic activity decreased obviously after hydrothermal aging.In the process of hydrothermal aging, the structure of La0 9Sr0 1CoO3 δ perovskite was stable, but the migration of palladium ions in the crystal phase of palladium-containing perovskite aggregated into The smaller PdO particles and the smaller PdO particles aggregated into larger particles.After hydrothermal aging, the number of bare palladium atoms on Pd / LaSrCo samples decreased, which led to the decrease of their catalytic activity. However, the surface of LaSrCoPd samples were bare An increase in the number of atoms, which leads to increased catalytic activity.