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 surfaces of the partition walls that each face the inflow-side cell and/or 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 from 3 to 10% based on the apparent area of the catalyst portion present on the partition wall.

Zoned diesel oxidation catalysts containing a higher precious metal loading in the inlet zone that the outlet zone and an equal or shorter length inlet zone are described. Emission treatment systems and methods of remediating nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons using zoned diesel oxidation catalysts are also described.

The presently claimed invention provides a tri-metallic layered catalytic article comprising: a) a top layer comprising platinum supported on at least one of an oxygen storage component, zirconia component and an alumina component, and rhodium supported on an oxygen storage component; b) a bottom layer comprising a front zone and a rear zone, said front zone comprising palladium supported on an oxygen storage component and an alumina component, and the rear zone comprises platinum supported on at least one of an alumina component, a ceria component, and an oxygen storage component; and c) a substrate, wherein the weight ratio of palladium to platinum is in the range of 1.0:0.4 to 1.0:2.0.

Provided are a hydrocarbon adsorbent, an exhaust gas purifying catalyst, and an exhaust gas purifying system, which are capable of adsorbing hydrocarbons, storing the adsorbed hydrocarbons up to a relatively high temperature, and desorbing the adsorbed and stored hydrocarbons at a relatively high temperature.

The hydrocarbon adsorbent contains a multipore zeolite containing, outside the zeolite framework, at least one metal selected from the group consisting of transition metals belonging to Groups 3 to 12 in the periodic table, amphoteric metals belonging to Groups 13 and 14 in the periodic table, alkali metals, and alkaline earth metals; and has a content ratio of the metal of 9% by mass or less relative to the multipore zeolite containing the metal.

The present invention provides a catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end and an outlet end with an axial length L; a first catalytic region comprising support material particles; at least some of the support material particles are rhodium-supporting support material particles having rhodium supported thereon at a concentration of from 0.001 to 3.5 wt. %, based on the weight of the rhodium-supporting support material particle; and the rhodium is present at a loading of up to 20 g/ft.sup.3 relative to the first catalytic region.

An exhaust gas purification catalyst for providing removal performance of methane, which is chemically stable includes a substrate that divides cells through which an exhaust gas flows and a catalyst layer that is provided on a surface of the substrate. The catalyst layer includes a palladium layer containing palladium that extends from a first end part which is an end part on the side of the cells into which an exhaust gas flows to a second end part which is an end part on the side from which an exhaust gas flows out, a platinum layer containing platinum that extends from the second end part to the first end part, and a rhodium layer containing rhodium that is laminated on both the palladium layer and the platinum layer.

The present invention relates to a catalyzed particulate filter and methods comprising the filter for treatment of an exhaust gas from a gasoline engine, the catalyzed particulate filter comprising a gasoline particulate filter (GPF); a major catalytic layer coated onto or within an inlet side, an outlet side, or both sides of the GPF surfaces, the major catalytic layer comprising a first composition, wherein the first composition comprising a first support material; and a first platinum group metal (PGM); and a minor functional material layer placed onto or within an inlet side, an outlet side, or both sides of the GPF surfaces; the minor catalytic layer comprising a second composition; wherein the major catalytic layer has a higher loading than the minor functional material layer; the minor functional material layer is placed on top of the major catalytic layer, or the major catalytic material layer is placed on top of the minor functional layer. The catalyzed particulate filter provides an improved catalytic efficiency in conjunction with an efficient filter.

The present invention relates to a three-way catalyst (TWC) for treatment of exhaust gases from internal combustion engines operated with a predominantly stoichiometric air/fuel ratio, so called spark ignited engines.

The invention is in the field of catalysis. In particular, the invention is directed to a catalytic reactor body, a method for the production of a catalytic reactor body and a use of a catalytic reactor body.

The invention provides a catalytic reactor body, comprising a circumferential reactor wall extending in a main fluid flow direction of the reactor body between a reactor inlet and a reactor outlet thereby forming a channel for conducting a fluid; and a reactor bed arranged in the channel and being integrally formed with the circumferential reactor wall, wherein the reactor bed forms a plurality of sub-channels for guiding the fluid from the reactor inlet to the reactor outlet, each sub-channel defining a predetermined fluid path between the reactor inlet and the reactor outlet and being configured for directing the fluid in a direction at least partly transverse to the main flow direction.

Subject of the invention is an exhaust gas purification system for a gasoline engine, comprising in consecutive order the following devices: ⋅ a first three-way-catalyst (TWC1), a gasoline particulate filter (GPF) and a second three-way-catalyst (TWC2), ⋅ wherein the platinum-group metal concentration (PGM) of the TWC2 is greater than the PGM of the GPF, wherein the PGM is determined in g/ft3 of the volume of the device. Also disclosed are methods in which the system is used and uses of the system.