Abstract: A porous composite includes a porous base material, and a porous collection layer. The collection layer is provided on the base material. The collection layer contains praseodymium oxide.

Abstract: A porous composite includes a porous base material and a porous collection layer formed on the base material. The collection layer has a thickness greater than or equal to 6 ?m. The collection layer has a plurality of large pores, each exposing the surface of the base material. A sum of areas of exposed regions of the base material that are each exposed from each large pore of the plurality of large pores is greater than or equal to 1% of the total area of the collection layer and less than or equal to 30% thereof. This allows the porous composite to achieve a favorable efficiency of collecting particulate matter and to increase the accessible area between the particulate matter and the collection layer and thereby accelerate oxidation of the particulate matter collected by the porous composite.

Abstract: A honeycomb filter including: a honeycomb structure having a porous partition wall provided surrounding a plurality of cells; and a plugging portion disposed to seal either one end portion on the inflow or the outflow end face side of the cells, wherein the cell in which the plugging portion is provided at the outflow end face side and the inflow end face side is open is defined as an inflow cell, the cell the plugging portion is provided at the inflow end face side and the outflow end face side is open is defined as an outflow cell, the honeycomb structure further has a trapping layer for the particulate matter on an inner surface side of the partition wall, the trapping layer includes a portion composed of a sintered body of CeO2 particles on at least a surface layer, and the average particle diameter is 1.1 ?m or less.

Abstract: A sensor element includes a ceramic layered body having a zirconia layer part and two alumina layer parts provided on both surfaces of the zirconia layer part, respectively, and a plurality of electrodes provided in the ceramic layered body. At least one of the two alumina layer parts contains Ti element, the zirconia layer part has a layer containing Zr element and Ti element in the vicinity of an interface with the at least one alumina layer part, and the layer contains Ti element in an amount from 0.05 to 5.0 mass %.

Abstract: A porous composite includes a porous base material, and a porous collection layer. The collection layer is provided on the base material. The collection layer contains praseodymium oxide.

Abstract: A porous composite includes a porous base material and a porous collection layer formed on the base material. The collection layer has a thickness greater than or equal to 6 ?m. The collection layer has a plurality of large pores, each exposing the surface of the base material. A sum of areas of exposed regions of the base material that are each exposed from each large pore of the plurality of large pores is greater than or equal to 1% of the total area of the collection layer and less than or equal to 30% thereof. This allows the porous composite to achieve a favorable efficiency of collecting particulate matter and to increase the accessible area between the particulate matter and the collection layer and thereby accelerate oxidation of the particulate matter collected by the porous composite.

Abstract: A honeycomb filter including: a honeycomb structure having a porous partition wall provided surrounding a plurality of cells; and a plugging portion disposed to seal either one end portion on the inflow or the outflow end face side of the cells, wherein the cell in which the plugging portion is provided at the outflow end face side and the inflow end face side is open is defined as an inflow cell, the cell the plugging portion is provided at the inflow end face side and the outflow end face side is open is defined as an outflow cell, the honeycomb structure further has a trapping layer for the particulate matter on an inner surface side of the partition wall, the trapping layer includes a portion composed of a sintered body of CeO2 particles on at least a surface layer, and the average particle diameter is 1.1 ?m or less.