A substrate (11) of an exhaust gas purification catalyst (10) includes inflow-side cells (21), outflow-side cells (22), and porous partition walls (23), each separating the inflow-side cell and the outflow-side cell. Catalyst portions (14, 15) are provided on the surfaces of the partition walls that each face the inflow-side cell and/or the surfaces of the partition walls that each face the outflow-side cell. In a cross section vertical to an exhaust gas flow direction, the percentage of the total area of voids, each void satisfying the expression L/{2(πS).sup.1/2}≤1.1 (wherein L is the perimeter of the void in the cross section, and S is the area of the void in the cross section), is greater than 10% to 30% or less based on the apparent area of the catalyst portion present on the partition wall. The content of zirconium element in terms of oxide (amount of ZrO2) in the catalyst portions is from 35 mass % to 85 mass %.

Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

The present invention relates to a particulate filter, in particular a particulate filter for use in an emission treatment system of an internal combustion engine. The particulate filter provides an advantageous combination of low back pressure and high fresh filtration efficiency.

An electrically heating converter includes: a pillar shaped honeycomb structure made of conductive ceramics, including: an outer peripheral wall; and a partition wall disposed on an inner side of the outer peripheral wall, the partition wall defining a plurality of cells, each of the cells penetrating from one end face to other end face to form a flow path; metal electrodes; conductive connecting portions arranged on a surface of the pillar shaped honeycomb structure; and a pressing member configured to press the metal electrodes against the conductive connecting portions, so that the metal electrodes are electrically connected to the pillar shaped honeycomb structure. Each of the conductive connecting portions has an electrical resistivity lower than that of the pillar shaped honeycomb structure.

There is provided an exhaust gas purification device that shows a high HC removal performance under a condition in which a rich air-fuel mixture is introduced. The exhaust gas purification device includes a substrate, a first catalyst layer, and a second catalyst layer. The substrate includes an upstream end and a downstream end. The first catalyst layer is disposed on a surface of the partition wall in an upstream region including the upstream end of the substrate. The second catalyst layer is disposed inside the partition wall in a downstream region including the downstream end of the substrate. The first catalyst layer contains a first metal catalyst and alumina-zirconia composite oxide. The second catalyst layer contains a second metal catalyst.

The present invention relates generally to the field of exhaust treatment systems for purifying exhaust gas discharged from a lean burn engine. The exhaust treatment system comprises a Diesel Oxidation Catalyst (DOC), a Catalyzed Soot Filter (CSF), a reductant injector, an AEI zeolite based Selective Catalyzed Reduction (SCR) catalyst and an Ammonia Oxidation Catalyst (AMOX) downstream to the AEI zeolite based SCR catalyst.

A pillar-shaped honeycomb structure including an outer peripheral side wall, a plurality of first cells provided on an inner peripheral side of the outer peripheral side wall, the first cells extending from a first end surface to a second end surface, each opening on the first end surface and having a sealing portion with an average void ratio of 4% or less on the second end surface, and a plurality of second cells provided on the inner peripheral side of the outer peripheral side wall, the second cells extending from the first end surface to the second end surface, each having a sealing portion with an average void ratio of 4% or less on the first end surface and opening on the second end surface, the first cells and the second cells being alternately arranged adjacent to each other with a partition wall interposed therebetween.

A process for coating substrates of motor vehicle exhaust gas catalysts is described, and includes steps of applying a suspension (e.g., washcoat) to a substrate, allowing a shear force to act on the applied washcoat, as in pressure transmitted by gas (e.g., air), and then sucking and/or pressing the washcoat into the substrate. The process in inclusive of providing the suspension (washcoat) containing the catalytic material from above in a metered charge process. An apparatus for carrying out the noted process steps is also featured.

The present invention provides an exhaust gas purification catalyst including a base material and a catalyst layer 20 that is arranged on the base material. The catalyst layer 20 includes a catalyst metal and a carrying material carrying the catalyst metal. The catalyst layer 20 satisfies below: (1) in a pore distribution curve measured by a mercury porosimeter, a peak for the largest pore volume exists within a range of a pore diameter equal to or more than 1 μm and not more than 10 μm; and (2) on an electron microscopy observation image (with a 1000-fold magnification) of a surface of the catalyst layer 20, when areas of a plurality of voids comprised in the electron microscopy observation image are respectively calculated, a standard deviation for the areas of the plurality of voids is not more than 30 μm.sup.2.

An apparatus (1) for dry powder coating a filter (2), comprising: i) a filter holder for holding a filter; ii) an inlet passage (5) for receiving a mixture of dry powder and gas, the inlet passage (5) communicating in use with an inlet face (3) of the filter (2) held by the filter holder; and iii) an outlet passage (6) comprising a first end (31) communicating in use with an outlet face (4) of the filter (2) held by the filter holder and a second end (32) communicating with a vacuum generator (9).

The inlet passage (5) comprises a diffuser (21) , and a divergent portion (22), downstream of the diffuser (21), that is outwardly tapered, or otherwise increases in its area for flow, towards the inlet face (3) of the filter (2).