Improved sulfur-resistant ability on CO oxidation of Pd/Ce＿(0.75)Zr＿(0.25)O＿2 over Pd/CeO_2-TiO_2 and Pd/CeO_2  

作　　者：沈美庆 林放 魏光曦 王建强 朱少春 

机构地区：[1]Key Laboratory for Green Chemical Technology of State Education Ministry, School of Chemical Engineering & Technology, Tianjin University [2]State Key Laboratory of Engines, Tianjin University [3]Collaborative Innovation Center of Chemical Science and Engineering

出　　处：《Journal of Rare Earths》2015年第1期56-61,共6页稀土学报（英文版）

基　　金：supported by the Introduction of Talent and Technology Cooperation Plan of Tianjin(14RCGFGX00849)

摘　　要：The influence of sulfation on Pd/Ce0.75Zr0.25O2, Pd/Ce O2-Ti O2 and Pd/Ce O2 was investigated. Physical structure and chemical properties of different catalysts were characterized by N2 adsorption, X-ray diffraction（XRD）, CO chemisorption, X-ray photoelectron spectroscopy（XPS）, Fourier transform infrared spectroscopy（FT-IR） and X-ray fluorescence（XRF）. After 10 h SO2 sulfation, it was found that the decrement on CO oxidation catalytic activity was limited on Pd/Ce0.75Zr0.25O2 compared to Pd/Ce O2-Ti O2 and Pd/Ce O2. It demonstrated that Pd/Ce0.75Zr0.25O2 was more sulfur resistant compared to the other two catalysts. After sulfur exposure, catalyst texture was not much influenced as shown by N2 adsorption and XRD, and surface Pd atoms were poisoned indicated by CO chemisorption results. Pd/Ce0.75Zr0.25O2 and Pd/Ce O2-Ti O2 exhibited less sulfur accumulation compared to Pd/Ce O2 in the sulfation process. Furthermore, XPS results clarified that surface sulfur amount, especially surface sulfates amount on the sulfated catalysts was more crucial for the deactivation in sulfur containing environment.The influence of sulfation on Pd/Ce0.75Zr0.25O2, Pd/Ce O2-Ti O2 and Pd/Ce O2 was investigated. Physical structure and chemical properties of different catalysts were characterized by N2 adsorption, X-ray diffraction（XRD）, CO chemisorption, X-ray photoelectron spectroscopy（XPS）, Fourier transform infrared spectroscopy（FT-IR） and X-ray fluorescence（XRF）. After 10 h SO2 sulfation, it was found that the decrement on CO oxidation catalytic activity was limited on Pd/Ce0.75Zr0.25O2 compared to Pd/Ce O2-Ti O2 and Pd/Ce O2. It demonstrated that Pd/Ce0.75Zr0.25O2 was more sulfur resistant compared to the other two catalysts. After sulfur exposure, catalyst texture was not much influenced as shown by N2 adsorption and XRD, and surface Pd atoms were poisoned indicated by CO chemisorption results. Pd/Ce0.75Zr0.25O2 and Pd/Ce O2-Ti O2 exhibited less sulfur accumulation compared to Pd/Ce O2 in the sulfation process. Furthermore, XPS results clarified that surface sulfur amount, especially surface sulfates amount on the sulfated catalysts was more crucial for the deactivation in sulfur containing environment.

关 键 词：Pd/Ce0.75Zr0.25O2 Pd/CeO2-TiO2 diesel oxidation catalyst SO2 poison XPS rare earths 

分 类 号：O643.36[理学—物理化学] TQ426.96[理学—化学]