title: Effects of synthesis methods on the performance of Pt + Rh/Ce0.6Zr0.4O2 three-way catalysts.
abstract: The 0.7 wt% Pt + 0.3 wt% Rh/Ce0.6Zr0.4O2 catalysts were fabricated via different methods, including ultrasonic-assisted membrane reduction (UAMR) co-precipitation, UAMR separation precipitation, co-impregnation, and sequential impregnation. The catalysts were physico-chemically characterized by N2 adsorption, XRD, TEM, and H2-TPR techniques, and evaluated for three-way catalytic activities with simulated automobile exhaust. UAMR co-precipitation- and UAMR separation precipitation-prepared catalysts exhibited a high surface area and metal dispersion, wide λ window and excellent conversion for NOx reduction under lean conditions. Both fresh and aged catalysts from UAMR-precipitation showed the high surface areas of ca. 60-67 m(2)/g and 18-22 m(2)/g, respectively, high metal dispersion of 41%-55%, and small active particle diameters of 2.1-2.7 nm. When these catalysts were aged, the catalysts prepared by the UAMR method exhibited a wider working window (Δλ = 0.284-0.287) than impregnated ones (Δλ = 0.065-0.115) as well as excellent three-way catalytic performance, and showed lower T50 (169°C) and T90 (195°C) for NO reduction than the aged catalysts from impregnation processes, which were at 265 and 309°C, respectively. This implied that the UAMR-separation precipitation has important potential for industrial applications to improve catalytic performance and thermal stability. The fresh and aged 0.7 wt% Pt + 0.3 wt% Rh/Ce0.6Zr0.4O2 catalysts prepared by the UAMR-separation precipitation method exhibited better catalytic performance than the corresponding catalysts prepared by conventional impregnation routes.
authors: Laboratory of Catalysis Chemistry and Nano-Science, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China. Electronic address: zhanzongcheng@emails.bjut.edu.cn.
authors: Zongcheng
authors: Z
authors: Zhan
authors: Laboratory of Catalysis Chemistry and Nano-Science, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
authors: Liyun
authors: L
authors: Song
authors: Laboratory of Catalysis Chemistry and Nano-Science, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
authors: Xiaojun
authors: X
authors: Liu
authors: Laboratory of Catalysis Chemistry and Nano-Science, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
authors: Jiao
authors: J
authors: Jiao
authors: Laboratory of Catalysis Chemistry and Nano-Science, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China.
authors: Jinzhou
authors: J
authors: Li
authors: Laboratory of Catalysis Chemistry and Nano-Science, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China. Electronic address: hehong@bjut.edu.cn.
authors: Hong
authors: H
authors: He
mesh_terms: D000397:Air Pollution / Q000517:prevention & control; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D002563:Cerium; D010984:Platinum; D015040:Zirconium; D012238:Rhodium
keywords: Pt and Rh nanoparticles; UAMR; precipitation; thermal stability; three way catalyst