Honeycomb structure and exhaust gas purifying device

A pillar shaped honeycomb structure, comprising:

• an outer peripheral wall;
• and
• a porous partition wall disposed inside the outer peripheral wall, the porous partition wall defining a plurality of cells, each of the cells extending from one end face to other end face to form a flow path,
• wherein a surface of the porous partition wall in the cells comprise a collecting layer having an average pore diameter lower than that of the porous partition wall;
• and
• wherein magnetic particles having a Curie point of 700° C. or higher are provided either or both between the surfaces of the porous partition wall and the collecting layer, and on the collecting layer,
• the collecting layer has a porosity of 40 to 80%,
• the collecting layer has an average pore diameter of 1 to 10 μm,
• the collecting layer has a thickness of 10 to 80 μm,
• a volume ratio of the magnetic particles is 1 to 30% to the total volume of the outer peripheral wall and the partition walls of the honeycomb structure,
• the pillar shaped honeycomb structure further comprises a heat insulating layer having a thermal conductivity lower than that of the collecting layer or the porous partition wall between the surface of the porous partition wall in the cells and the collecting layer,
• the porous partition wall is made of at least one, two or more materials selected from alumina (Al2O3), MgO, cordierite (2MgO·2SiO2·5SiO2), silicon carbide (SiC), aluminum titanate (Al2O3·TiO2), silicon nitride (Si3N4), mullite (3Al2O3·2SiO2), a silicon-silicon carbide-based composite material, and silicon carbide-cordierite based composite material, and
• the heat insulating layer is made of at least one, two or more materials selected from ZrO2, SiO2, TiO2, and glass.