Fundamental Study and Possible Application of New Concept Honeycomb Substrate for Emission Control

To meet the legislation of future diesel emission level, high-performance catalysts are desired. One of the key technologies to realize the catalyst is to highly disperse the precious metal on the catalytic support with high specific surface area. The catalytic support with high specific surface area is directly extruded in honeycomb configuration (New honeycomb substrate) and, as a result, the amount of catalytic support and the surface area reached to around factor of two compared with the conventional catalytic support. Through the fundamental study and the evaluation of the HC/CO conversion performance of the catalyst made of the new honeycomb substrate by Synthetic Gas Bench and/Engine Bench, it was found that the new honeycomb substrate could highly disperse the precious metal even after thermal aging and that the gas conversion efficiency is same level even if loaded precious metal amount is smaller compared with the conventional catalyst made of the catalytic support that is wash-coated with γ-alumina on cordierite substrate. This new honeycomb substrate makes it possible to reduce the volume of catalytic support or to enhance the storage capacity of NOx in NSC due to its high surface area.