Abstract: A zeolite structure is provided which has partition walls composed of a zeolite ion-exchanged with a metal ion and forming a plurality of cells extending from one end face of the zeolite structure to its other end face and functioning as a passage of fluid and which has a honeycomb shape. The content per unit zeolite amount of the metal ion in the surface portion of the partition wall is larger than the content per unit zeolite amount of the metal ion in the inner portion of the partition wall and is preferably 1.1 to 5.0 times the content per unit zeolite amount of the metal ion in the inner portion of the partition wall.

Abstract: A honeycomb structural body includes porous partition walls arranged to form a plurality of cells which become through channels of a fluid, porosities of the partition walls are from 45 to 70%, a pore diameter distribution of the partition walls is measured by mercury porosimetry, the pore diameter distribution indicates a bimodal distribution, in the bimodal distribution, a pore diameter at the maximum peak value of a small pore side distribution is from 1 to 10 ?m, and a pore diameter at the maximum peak value of a large pore side distribution exceeds 10 ?m, and a ratio between a pore volume of the small pores and a pore volume of the large pores is in a range of 1:7 to 1:1 in the honeycomb structural body.

Abstract: A honeycomb filter includes a tubular honeycomb structure having porous partition walls with which there are formed a plurality of cells extending from one end surface to the other end surface to become through channels of a fluid; and plugged portions arranged in one open end portion of each of predetermined cells and the other open end portion of each of the remaining cells, porosities of the partition walls are 46% or less, a pore volume ratio of pores having pore diameters of 40 ?m or more is 7.5% or less, and a pore volume ratio of pores having pore diameters of 10 ?m or less is 25% or less, a permeability of the honeycomb structure is 0.8 ?m2 or more, and a coefficient of thermal expansion of the honeycomb structure in a range of 40 to 800° C. is 1.0×10?6/° C. or less.

Abstract: A honeycomb structural body includes porous partition walls arranged to form a plurality of cells which become through channels of a fluid, porosities of the partition walls are from 45 to 70%, a pore diameter distribution of the partition walls is measured by mercury porosimetry, the pore diameter distribution indicates a bimodal distribution, in the bimodal distribution, a pore diameter at the maximum peak value of a small pore side distribution is from 1 to 10 ?m, and a pore diameter at the maximum peak value of a large pore side distribution exceeds 10 ?m, and a ratio between a pore volume of the small pores and a pore volume of the large pores is in a range of 1:7 to 1:1 in the honeycomb structural body.

Abstract: A zeolite structure which has partition walls composed of a zeolite ion-exchanged with a metal ion and forming a plurality of cells extending from one end face of the zeolite structure to its other end face and functioning as a passage of fluid and which has a honeycomb shape, wherein the content per unit zeolite amount of the metal ion in the surface portion of the partition wall is larger than the content per unit zeolite amount of the metal ion in the inner portion of the partition wall and is preferably 1.1 to 5.0 times the content per unit zeolite amount of the metal ion in the inner portion of the partition wall.