Patent ID: 8334230

Claim:
A honeycomb structure comprising: at least one honeycomb unit having a longitudinal direction and comprising: a zeolite; an inorganic binder; and walls having a thickness of from about 0.10 mm to about 0.50 mm and extending along the longitudinal direction to define through-holes; a center area inside a boundary line passing through positions located at substantially a half of a length from a center of the honeycomb structure to a periphery of the honeycomb structure in a cross section perpendicular to the longitudinal direction; a peripheral area outside the boundary line; a thickness of the walls located in the peripheral area being larger than a thickness of the walls located in the center area; and a first opening ratio in the center area in the cross section being larger than a second opening ratio in the peripheral area in the cross section, wherein the zeolite comprises a secondary particle having an average particle diameter from about 0.5 μm to about 10 μm.