A ceramic precursor composition suitable for sintering form a ceramic material or structure therefrom, for example, a ceramic honeycomb structure, a ceramic material or structure, for example, a ceramic honeycomb structure obtainable by sintering said ceramic precursor composition, a method for preparing said ceramic precursor composition and ceramic material or structure, for example, ceramic honeycomb structure, a diesel particulate filter comprising said ceramic structure, a selective diesel particulate filter comprising said ceramic structure, a gasoline particulate filter comprising said ceramic structure, a vehicle comprising said diesel particulate filter, selective diesel particulate filter or gasoline particulate filter, and a SCR catalyst system comprising said ceramic material or structure.

Porous ceramic honeycomb articles for use as particulate filters and processes for making the same are described herein. The porous ceramic honeycomb articles include a fired cordierite body. The fired cordierite body has a microcrack parameter (Nb.sup.3) of about 0.05 to about 0.25 prior to exposure to a microcracking condition. After exposure to the microcracking condition, the fired cordierite body has a microcrack parameter (Nb.sup.3) at least 20% greater than the microcrack parameter prior to exposure to the microcracking condition. The fired cordierite body has a coefficient of thermal expansion (CTE) of about 7.010.sup.7/ C. to about 15.010.sup.7/ C. over from about 25 C. to about 800 C. prior to exposure to the microcracking condition and a coefficient of thermal expansion of about 1.010.sup.7/ C. to about 10.010.sup.7/ C. over from about 25 C. to about 800 C. after exposure to the microcracking condition. The microcrack parameter may include a thermal cycle or a chemical treatment.

A ceramic honeycomb filter including a ceramic honeycomb structure having large numbers of flow paths partitioned by porous cell walls, and plugs disposed in the flow paths alternately on the exhaust gas inlet or outlet side, to remove particulate matter from an exhaust gas passing through the porous cell walls; the porous cell walls having porosity of 45-75%, the median pore diameter A (m) of the cell walls measured by mercury porosimetry, and the median pore diameter B (m) of the cell walls measured by a bubble point method meeting the formula of 35<(AB)/B10070, and the maximum pore diameter of the cell walls measured by a bubble point method being 100 m or less.

A pillar shaped honeycomb structure includes: an outer peripheral wall; and porous partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the cells extending from one end face to other end face to form a flow path, wherein the cells include a plurality of wire pieces made of a magnetic substance, the wire pieces being provided apart from each other via spaces or buffer materials in an extending direction of the cells.