A novel insight into the preparation method of Pd/Ce0.75Zr0.25O2-Al2O3 over high-stability close coupled catalysts

作     者：Sun, Min Hu, Wei Cheng, Tianqiong Chen, Yusheng Yao, Peng Zhao, Ming Yuan, Shandong Chen, Yaoqiang 

作者机构：Sichuan Univ Coll Chem Chengdu 610064 Sichuan Peoples R China Sichuan Univ Coll Chem Engn Chengdu 610064 Sichuan Peoples R China Sichuan Univ Inst New Energy & Low Carbon Technol Chengdu 610064 Sichuan Peoples R China 

出 版 物：《APPLIED SURFACE SCIENCE》 (应用表面科学)

年 卷 期：2019年第467卷

页      面：723-739页

核心收录：

学科分类：07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：National Hi-tech Research and Development Program of China (863 Program) [2015AA034603] 

主　　题：Thermal stability Preparation method Interaction Palladium dispersion Catalytic performance 

摘      要：A series of Ce0.75Zr0.25O2-Al2O3 samples were prepared by conventional coprecipitation, wet impregnation method and novel deposition precipitation, after the corresponding Pd-only close coupled catalysts were obtained by incipient wet impregnation. Differences in surface properties and catalytic performance were investigated systematically by a wealth of characterizations. XPS, H-2-TPR and CO chemisorption revealed that the different preparation methods of Ce0.75Zr0.25O2-Al2O3 led to different intensity of interaction between PdO species and support, thus forming different palladium dispersions. BET, XRD and activity evaluation indicated the catalyst obtained by novel deposition precipitation presented superior textural properties, catalytic performance and thermal stability, due to the strongest interaction proved by H-2-TPR, XPS and CO chemisorption, which could retard the sintering of noble metal during the aging process. HRTEM images indicate for the catalysts, PdO species are mainly dispersed and stabilized on the ceria resulting from the lower redox potential of Pd2+/Pd-0 (0.95 V) than that of Ce4+/Ce3+ (1.72 V). Consequently, it owned higher surface PdO content and dispersion than the catalysts prepared by coprecipitation and impregnation method, presenting its higher catalytic properties.