Newly Developed Flow Through Catalytic Honeycomb for Improving Future Emission Control - (PPT)

摘要

To find out the relationship between pore diameter distribution and gas conversion performance or substrate strength, NCH substrate with various macro pores were prepared and evaluated. Although the substrate strength drastically decreases with increasing macro pore diameter, CO/THC conversion efficiency does not depend on macro pore diameter. Because The reaction rate over the Pt surface is much larger than the rate of gas diffusing into the macro pores, the CO/THC oxidation performance depend not on the macro pore diameter but on the Pt surface area. The macro-pore affects not the performance of the gas oxidation reaction but substrate strength. Based on this, it is determined that we could eliminate the trade-off between the strength and the performance of the gas oxidation reaction by removing pores which are not necessary for CO/THC conversion. The number of active sites on Pt mainly affects the performance of the CO/THC oxidation reaction. The NO_x reduction reaction is determined by the NH_3 adsorption site, that is, the number of acid sites of zeolite. NO conversion efficiency depends not on cell geometries.