Conversion Characteristics of Double-Layer Washcoat Tri-Metal Three-Way Catalyst Using High Cell Density Substrate

• Published in: JSME International Journal Series B Fluids and Thermal Engineering Vol. 48; no. 4; pp. 874 - 881
• Main Authors: CHOI, Byungchul, JEONG, Jongwoo, SON, Geonseog, UNG, Myunggun J
• Format: Journal Article
• Language: English
• Published: Tokyo The Japan Society of Mechanical Engineers 2005; Japan Society of Mechanical Engineers; Japan Science and Technology Agency
• Subjects: Air pollution caused by fuel industries; Applied sciences; Catalyzer; Double-Layer Washcoat; Durability; Emission; Energy; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Gasoline Engine; Pollution reduction; Precious Metal(PM); Stack gas and industrial effluent processing; Three-Way Catalyst; Precious Metal(PM); Air pollution control; Gasoline engine; Emission; Durability; Palladium; Double-Layer Washcoat; Supported catalyst; Catalyzer; Rhodium; Platinum; Three way catalyst; Three-Way Catalyst; Catalyst activity
• ISSN: 1340-8054; 1347-5371
• DOI: 10.1299/jsmeb.48.874

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.