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Fresh Pd/CeO_2/Al_2O_3 close coupled catalyst was prepared by the stepwise impregnation method and calcined at 550 °C for 3 h, which was then pretreated at 700, 800, and 900 °C for 3 h, respectively. Finally, these pretreated catalysts were aged at 1000 °C for 3 h to study their anti-aging properties. The catalytic activities of the catalysts were investigated detailedly, and the results showed that the catalyst pretreated at 800 °C before aging treatment possessed the best anti-aging performance for C_3H_8 oxidation. XRD and XPS results indicated that well-crystallized CeO_2 particles were formed during calcinations at 800 °C, which made CeO_2 an effective promoter. HRTEM revealed that Pd particles found on the edge of CeO_2 over the aged catalyst pretreated at 800 °C were relatively smaller than those over the catalysts without pretreatment. H_2-TPR and XPS results also implied that the interaction between well-crystallized CeO_2 and Pd suppressed the deactivation of PdO sites and further enhanced the catalytic performance.
Fresh Pd / CeO 2 / Al 2 O 3 close coupled catalyst was prepared by the stepwise impregnation method and calcined at 550 ° C for 3 h, which was then pretreated at 700, 800, and 900 ° C for 3 h, respectively. Finally, these pretreated catalysts were aged at 1000 ° C for 3 h to study their anti-aging properties. The catalytic activities of the catalysts were investigated detailedly, and the results showed that the catalyst pretreated at 800 ° C before aging treatment possessed the best anti-aging performance for C_3H_8 oxidation. XRD and XPS results indicated that well-crystallized CeO_2 particles were formed during calcinations at 800 ° C, which made CeO_2 an effective promoter. HRTEM revealed that Pd particles found on the edge of CeO_2 over the aged catalyst pretreated at 800 ° C were relatively smaller than those over the catalysts without pretreatment. H_2-TPR and XPS results also implied that the interaction between well-crystallized CeO_2 and Pd suppressed the deactivation of PdO sites and further enhanced the catalytic performance.