Improvements In Converter Durability and Activity via Catalyst Formulation

The performance data for monolithic ceramic converters, to date, shows that fuel management, engine characteristics, substrate design, catalyst formulation, substrate/coating interaction, and packaging design have a profound influence on converter durability and sustained activity and that certain trade-offs are necessary to optimize the overall performance of the converter system. This paper concentrates on the effect of the catalyst system on light-off performance, steady state conversion efficiency, pressure drop, high temperature strength, and thermal shock resistance. The physical properties and engine test data for Corning's EX-20, 400/6 square cell substrate with two different catalyst formulations, production high-tech vs advanced high-tech, show that the advanced catalyst results in marked improvement in mechanical durability and catalytic activity over that achievable with the production catalyst due to improved substrate/coating interaction.