A honeycomb structure body has a skin part of a cylindrical shape and a honeycomb structural part formed with the skin part together in a monolithic body. The skin part and the honeycomb structural part have partition walls of a porous structure. The cells have first cells arranged adjacent to the skin part and second cells arranged adjacent to the first cells. The skin part, the first cells and the second cells form an outer peripheral section. A central section is arranged inside the outer peripheral section. The honeycomb structure body satisfies a relationship in which a thermal expansion coefficient of the outer peripheral section is greater than a thermal expansion coefficient of the central section.

A honeycomb filter includes a pillar-shaped honeycomb structure having porous partition walls provided, surrounding a plurality of cells which serve as fluid through channels extending from an inflow end face to an outflow end face, and porous plugging portions provided either at the ends on the inflow end face or the outflow end face of the cells, wherein the plugging portions are composed of a porous material, the honeycomb structure has a central region and a circumferential region, and a ratio of an area of the circumferential region with respect to that of the central region ranges from 0.1 to 0.5, a plugging length L1 in the cell extending direction of a central plugging portion in the central region is larger than a plugging length L2 of a circumferential plugging portion in the circumferential region, L1 ranges from 7 to 9 mm, and L2 from 3 to 6 mm.

A ceramic porous body including: skeleton portions including an aggregate and at least one bonding material; and pore portions formed between the skeleton portions, the pore portions being capable of allowing a fluid to flow therethrough, wherein the pore portions have a pore volume ratio of pores having a pore diameter of from 10 to 15 m, of from 4 to 17% or more.

A honeycomb structure has a plurality of cells formed by a plurality of partition walls. The partition walls are formed of a porous material composed predominantly of cordierite. Each partition wall includes surface layer portions having a porosity of 50% or more and an inside portion having a porosity of 50% or more, the surface layer portions being portions ranging respectively from opposite surfaces to a depth corresponding to 25% of the thickness of the partition wall, and the inside portion being the other portion. The surface layer portions and the inside portion both include pores having axial pore widths of less than 30 m and pores having axial pore widths of 30 m or more. A mean axial pore width in the surface layer portions is smaller than a mean axial pore width in the inside portion.

In order to provide a shaped body which has good high-temperature resistance, to which a coating material adheres permanently, and which is easy to produce, a shaped body is proposed which has a channel structure formed by shaping a material of the shaped body and a pore structure in the material of the shaped body, wherein the material of the shaped body comprises a particulate base material or is formed therefrom at least in part, wherein the base material comprises a cordierite material and/or a mullite material, wherein particles of the base material are connected to one another directly and/or indirectly, and wherein approximately 5 vol. % of a coating material or more, based on a total volume of the pore structure, can be or is absorbed into pores of the pore structure.

A filtration article is disclosed comprising a plugged porous honeycomb filter body, deposits of inorganic particles within the plugged honeycomb filter body, the deposits having a porosity in a range of greater than 95% to less than or equal to 99.9% and an average thickness in a range of greater than or equal to 0.5 m to less than or equal to 200 m, and at least some of the inorganic particles being fused to each other and/or to the filter body. The particles are fused by one or more of low-melting inorganic particles, inorganic particles capable of chemical bonding organic fusion bonds or organic chemical bonds between inorganic particles coated with an organic binder.

A plugged honeycomb structure has a plurality of cells defined by partition walls to become through channels for fluid, one end of each of the predetermined cells is plugged by a plugging member, the other end of each of the residual cells is plugged by the plugging member, the partition wall is made of a cordierite component as a main component, and a value obtained by dividing Young's modulus of a plugging structure portion formed by the partition walls and the plugging member by Young's modulus of a cell structure portion formed by the partition walls is in a range of 1.05 to 2.00.

A honeycomb body having a porous ceramic honeycomb structure with a first end, a second end, and a plurality of walls having wall surfaces defining a plurality of inner channels. A highly porous layer is disposed on one or more of the wall surfaces of the honeycomb body. The highly porous layer has a porosity greater than 90%, and has an average thickness of greater than or equal to 0.5 m and less than or equal to 10 m. A method of making a honeycomb body includes depositing a layer precursor on a ceramic honeycomb body and binding the layer precursor to the ceramic honeycomb body to form the highly porous layer.

An exhaust purification system includes an LAF sensor provided in an exhaust pipe and generates a signal corresponding to an air-fuel ratio of exhaust gas. An upstream catalytic converter is downstream of the LAF sensor and has a catalyst to purify the exhaust gas. An O2 sensor is downstream of the upstream catalytic converter, and generates a signal corresponding to the air-fuel ratio of the exhaust gas. A GPF is downstream of a the O2 sensor and purifies the exhaust gas. An ECU controls an air-fuel mixture in an engine using output signal KACT of the LAF sensor and an output signal VO2 of the O2 sensor such that the air-fuel ratio of exhaust gas flowing into the GPF converges to a target value near the stoichiometric ratio. The GPF has a filter substrate and a downstream TWC supported by a partition of the filter substrate.

A plugged honeycomb structure includes a honeycomb structure body, and a plurality of plugging portions, the honeycomb structure body further includes pass-through hole portions each of which is formed in at least a part of a partition wall intersection portion in which the partition walls intersect in one end face and each of which interconnects a pair of cells facing each other at a position corresponding to the partition wall intersection portion to enable pass-through of a fluid, and a value obtained by dividing a diameter of a first virtual inscribed circle inscribed at a position of a minimum hole width of the pass-through hole portion by a diameter of a second virtual inscribed circle inscribed at a position of a minimum plugging width between the plugging portions facing each other is in a range of 0.05 to 0.74.