Honeycomb structural body for exhaust emission control and honeycomb catalyst body for exhaust emission control

A honeycomb structural body for exhaust gas purification, which comprises,

• a plurality of cell partition walls (ribs) forming a group of cells adjacent to each other, and
• a honeycomb outer wall surrounding and holding the group of cells, wherein an exhaust gas flowing through the cells is purified by a catalyst layer to be loaded on the cell partition walls or by a catalyst to be contained in the cell partition walls,
• characterized in that the cell partition walls satisfy a relation shown by the following expression (1), with respect to the material properties and the cell structure:
• σ/E≧0.0161·α·(GSA)/{HD·(ρc·C·λc)0.5} (b 1)
• {in the expression (1), σ [MPa] is a material strength (one-rib bending);
• E [MPa] is a material Young's modulus (one-rib bending);
• α [1/K] is a thermal expansion coefficient of honeycomb in a direction perpendicular to a direction of gas flow, with a proviso of α≧1;
• GSA [m2/m3] is a geographical surface area per volume of honeycomb structure;
• HD [m] is a hydraulic diameter of the cell of honeycomb structure;
• ρc [kg/m3] is a bulk density of honeycomb structure;
• C [J/kgK] is a material specific heat;
• and λc [W/mK] is a thermal conductivity of the cell of honeycomb structure which is λ·b/p (λ is a material thermal conductivity [W/mK], b is a rib thickness [m], and p is a cell pitch (an interval between ribs) [m])}.