Effective Catalyst layout for ultra thin-wall and high cell-density ceramic substrate 973118
Catalytic performance can be improved by reducing bulk density (BD) and increasing geometric surface area (GSA) of ceramic substrate. Ultra thin-wall / high cell-density ceramic substrates, such as 3 mil/ 600 cpsi and 2 mil/ 900 cpsi have improved the catalytic performance over the conventional 6 mil/ 400 cpsi substrates. and are expected to help in complying with future emission regulations, as well as catalyst down-sizing. This paper describes the effects of BD and GSA using Pd-based catalysts. The significant reduction of hydrocarbons emissions was demonstrated at close-coupled location, and dual bed design was proven effective. The effectiveness at under-floor location was not as significant as the close-coupled location. This paper proposes the converter layout of dual bed close-coupled converter consisting of small volume 2 mill 900 cpsi front catalyst and large volume 3 mil/ 600 cpsi rear catalyst. The underfloor converter may be eliminated, if sufficient catalyst volume can be taken for the close-coupled converter.
Citation: Umehara, K., Yamada, T., Hijikata, T., Ichikawa, Y. et al., "Effective Catalyst layout for ultra thin-wall and high cell-density ceramic substrate," SAE Technical Paper 973118, 1997, https://doi.org/10.4271/973118. Download Citation
Kazuhiko Umehara, T. Yamada, T. Hijikata, Y. Ichikawa, F. Katsube
SAE Brasil 97 VI International Mobility Technology Conference and Exhibit