Ngk Insulators, Inc.

Chika Goto

Yukio Miyairi

Masataka Yamashita

Toshio Yamada

Shogo Hirose

Tsubasa Aoki

A honeycomb structure includes a pillar-shaped honeycomb structure body having a porous partition wall defining a plurality of cells serving as fluid through channels extending from a first end face to a second end face, and having a circumferential wall disposed so as to encompass the circumference of the partition wall, wherein a thickness of the partition wall is 50 to 132 &#x3bc;m, a porosity of the partition wall is 40 to 55%, an open frontal area of pores on the surface of the partition wall per unit surface area of the partition wall is 10 to 15%, and a percentage (S/S&#xd7;100%) of the ratio of an opening area Sof the pores having an opening diameter of 10 &#x3bc;m or less to a total opening area Sof the pores opened to the surface of the partition wall is 90% or more.

Honeycomb structure

A substrate with a surface-collection-layer includes a honeycomb substrate having a porous partition wall that defines and forms cells, and a plurality of plugging portions. A surface-collection-layer is formed on a surface of the partition wall that forms the remaining cells, and the thickness of the surface-collection-layer on the outlet-side open end is larger than the thickness of the surface-collection-layer in a center area of the substrate. The partition wall has predetermined thickness, porosity, and average pore size. The surface-collection-layer has a predetermined thickness, porosity, and average pore size, and the substrate has a predetermined cell density.

Substrate with surface-collection-layer and catalyst-carrying substrate with surface-collection-layer

There is provided a honeycomb catalyst body including, a honeycomb substrate, plugging portions, and a three way catalyst. All the cells are open in the inflow side end face, the honeycomb substrate has two regions of an inflow side region and an outflow side region, the inflow side region of the honeycomb substrate is a region from the inflow side end face to a position of 10 to 90% of a length in an central axial direction of the honeycomb substrate from the inflow side end face, and 100 to 400 g/L of the three way catalyst is loaded on the partition walls in the inflow side region, no catalyst is loaded on the partition walls in the outflow side region, and a ratio of the length to a diameter of the inflow side end face of the honeycomb substrate is 1.1 to 2.0.

Honeycomb catalyst body

A honeycomb structure wherein the thickness of each partition wall is 50.8 &#x3bc;m inclusive to 161.5 &#x3bc;m exclusive, the cell density is 15.5 to 62.0 cells/cm, the cell opening ratio of the honeycomb structure body is 76 to 91%, the porosity of the partition walls is 35 to 45%, the average pore diameter of the partition walls is 2 &#x3bc;m inclusive to 10 &#x3bc;m exclusive, the material for the partition walls includes at least one member selected from the group consisting of cordierite, aluminum titanate, silicon carbide, alumina and mullite, and the value obtained by dividing the average pore diameter of the partition walls by the thickness of the partition walls is larger than 0.04 but smaller than 0.065.

There is provided a honeycomb catalyst body comprising a honeycomb base body having porous partition walls forming a plurality of divided cells which extend from one end face of honeycomb base body to its other end face and which function as a fluid passage, and an outer wall present at the outermost peripheral portion of honeycomb base body, plugged portions provided so as to plug part of the plurality of divided cells, and a catalyst loaded on the partition walls of honeycomb base body. The plurality of divided cells include outermost peripheral cells formed by the partition walls and the outer wall, and of the outermost peripheral cells, those cells whose hydraulic diameter is 5 to 75% of the hydraulic diameter of a cell other than the outermost peripheral cells, are through-cells having no plugged portion.

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Nagoya, Japan

Chika Goto