ABSTRACT
The catalytic control of automobile exhaust pollutants is a common practice in the United States and Japan, and there are strong indications that the technology may be introduced in other parts of the world. Automobile exhaust catalysts have to satisfy a wide range of chemical and physical requirements. This chapter aims to propose new catalyst particle geometry, discuss its theoretical advantages, optimize its shape and pore structure with the help of appropriate mathematical models, and show first evidence of their improved performance in laboratory-scale reactors. A flat-slab geometry was used for spoked extrudates, neglecting curvatures due to the relative thinness of their walls with respect to the curvature radius. Pellet-type catalysts are easier to replace in their converter and have a favorable resistance to thermal excursions due in part to the higher melting point of alumina compared to that of cordierite.
