JSME International Journal Series B Fluids and Thermal Engineering
Online ISSN : 1347-5371
Print ISSN : 1340-8054
ISSN-L : 1340-8054
Conversion Characteristics of Double-Layer Washcoat Tri-Metal Three-Way Catalyst Using High Cell Density Substrate
Byungchul CHOIJongwoo JEONGGeonseog SONMyunggun J UNG
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2005 Volume 48 Issue 4 Pages 874-881


The research was conducted to evaluate conversion characteristics of three-way catalyst(TWC) with a double-layer washcoat to improve the light-off temperature and the thermal durability. The evaluations considered factors such as the PM loading ratio and loading quantity of the tri-metal catalyst for Rh-Pd-Pt configuration, the washcoat composition, and the cell density. The higher cell density of TWC can improve the light-off temperature because of the lower heat capacity of the substrate and the increase of the surface area. Loading quantity and ratio of precious metals has appropriate value to light-off performance in each cell density of substrate. A proper selection of the bottom layer washcoat loaded with Pd can promote thermal stability and the upper layer washcoat with an excellent ability of oxygen storage can improve the light-off performance and the durability of the double-layer TWC. The best TWC with double-layer was 9Hy(0.6x11x3) with 140cell/cm2 substrate.

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© 2005 by The Japan Society of Mechanical Engineers
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