title: Preparation of ceria-zirconia by modified coprecipitation method and its supported Pd-only three-way catalyst.
abstract: A CeO2-ZrO2 compound with mixed phase composition (CZ4) was prepared by modified co-precipitation method, and for comparison, single-phase Ce(0.2)Zr(0.8)O2, Ce(0.5)Zr(0.5)O2 and Ce(0.8)Zr(0.2)O2 were synthesized via simultaneous co-precipitation method. The textural, structural and redox properties, together with the catalytic performance of the supported Pd-only three-way catalysts were investigated systematically. The results revealed that the generation of numerous interface sites in Pd/CZ4 due to its mixed phase composition (as confirmed by TEM observation) had a positive influence on modifying its structural, redox properties and thermal stability. The XRD and Raman results revealed that the highest structural stability was obtained by Pd/CZ4 with negligible lattice variation and slightest grain growth after aging treatment. The XPS analysis demonstrated that the compositional heterogeneity of Pd/CZ4 could facilitate the formation of Ce(3+), and was beneficial to preserve high dispersion of Pd as well as maintain Pd at a more oxidized state. The H2-TPR and oxygen storage capacity measurements indicated that Pd/CZ4 possessed highest reduction ability as well as largest oxygen storage capacity regardless of thermal aging treatment. And consequently Pd/CZ4 exhibited improved three-way catalytic activity compared with the catalysts supported on single-phase Ce(x)Zr(1-x)O2 both before and after thermal aging treatment.
authors: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Sichuan, Chengdu 610064, China.
authors: Li
authors: L
authors: Lan
authors: Sichuan Zhongzi Exhaust Gas Cleaning Co., Ltd., Sichuan, Chengdu 611731, China.
authors: Shanhu
authors: S
authors: Chen
authors: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Sichuan, Chengdu 610064, China.
authors: Yi
authors: Y
authors: Cao
authors: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Sichuan, Chengdu 610064, China.
authors: Ming
authors: M
authors: Zhao
authors: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Sichuan, Chengdu 610064, China.
authors: Maochu
authors: M
authors: Gong
authors: Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Sichuan, Chengdu 610064, China; Center of Engineering of Vehicular Exhaust Gases Abatement, Sichuan Province, Sichuan, Chengdu 610064, China; Center of Engineering of Environmental Catalytic Material, Sichuan Province, Sichuan, Chengdu 610064, China. Electronic address: nic7501@scu.edu.cn.
authors: Yaoqiang
authors: Y
authors: Chen
keywords: Interface sites; Mixed phase composition; Modified coprecipitation method; Pd-only three-way catalysts