A honeycomb filter includes a honeycomb structure body having porous partition walls defining a plurality of cells which become through channels for fluid, plugging portions disposed in open ends of the cells, and a protective layer disposed to cover at least the surface of the honeycomb structure body, each of the honeycomb structure body and the plugging portion has a structure constituted of aggregates made of silicon carbide and a bonding material which bonds the aggregates to one another, the protective layer is a layer in which silicon is present as much as 40 mass % or more and oxygen is present as much as 40 mass % or more and a thickness is 0.5 μm or more, and an outer end face of both end faces of the plugging portion has an exposed region in which the protective layer is not disposed.

A catalyst includes LTA zeolite including copper ions, wherein a Si/Al ratio of the LTA zeolite is 2 to 50. The catalyst is coated on a honeycomb carrier or a filter. The catalyst removes NOx from a reaction gas at 100° C. or above. The catalyst has an NOx conversion rate of 80% at 450° C. or above.

A honeycomb structure includes a honeycomb substrate having porous partition walls defining a plurality of cells extending from one end face to the other end face, and one-side plugging portions configured to plug the cells in the one end face in accordance with a predetermined arrangement standard, and the partition walls include catalyst impregnated partition walls formed in a first region of a predetermined length extending from the one end face in which the one-side plugging portions are provided, along an axial direction of the honeycomb substrate and formed by impregnating a catalyst into partition wall inner portions, and catalyst layer partition walls formed in a second region of a predetermined length extending from the other end face along the axial direction of the honeycomb substrate and having catalyst layers which coat partition wall surfaces with the catalyst in the form of layers.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst composition comprises a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

A catalytic filter with enhanced catalyst carrying capability comprising high temperature resistant inorganic fibers, at least one binder and at least one high surface area catalyst support material. Also, a method for making the catalytic filter having at least one high surface area catalyst support material.

The invention relates to a coating suspension containing at least one platinum group metal on a support material, as well as manganese(II) carbonate, and to a method for coating a catalyst support substrate.

A Diesel Particulate Filter (DPF) assembly configured to be incorporated in the exhaust gas stream, the DPF assembly comprising: Quartz/Composite ceramic mixture disposed as filter elements, mechanical support components and optional electrical soot removal solutions including electrical, di-electrical and microwave solutions.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst comprises a first layer consisting essentially of a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.

Described is a method of coating the inside of an exhaust gas purification catalyst filter with a predetermined amount of catalyst slurry while adjusting the distribution of catalyst components in or on a cell wall of the filter. A predetermined amount of catalyst slurry can be injected into an internal channel of a filter to solve conventional problems caused by excess or surplus slurry injection. The predetermined amount of slurry injected into the internal channel of the filter is coated on or in the cell wall, depending on the viscosity and particle size of the slurry. This enables a coating profile in which the slurry distribution at a front portion of the filter and the slurry distribution at a back portion of the filter differ from each other. In addition, the coating profile on the inner surface of the cell wall or in the pores of the cell wall can be adjusted through the subsequent air blowing, so that the back pressure of the filter and the performance of the catalyst filter, such as catalytic activity, can be improved. In addition, the coating length in the filter can be adjusted by controlling the pressure of air during the air blowing.

A NO.sub.x adsorber catalyst and its use in an emission treatment system for internal combustion engines, is disclosed. The NO.sub.x adsorber catalyst composition comprises a support material, one or more platinum group metals disposed on the support material, and a NO.sub.x storage material.