Systems and methods for removal of gas phase contaminants may utilize catalytic oxidation. For example, a method may include passing a gas that includes a gas phase contaminant through a catalytic membrane reactor at a temperature of about 150 C. to about 300 C., wherein the catalytic membrane reactor includes a bundle of tubular inorganic membranes, wherein each of the tubular inorganic membranes comprise a macroporous tubular substrate with an oxidative catalyst and a microporous layer disposed on a bore side of the macroporous tubular substrate, and wherein at least about 50% of the gas flows through the tubular inorganic membranes in a Knudsen flow regime; and oxidizing at least some of the gas phase contaminant with the oxidative catalyst layer, thereby reducing a concentration of the gas phase contaminant in the gas.

The present invention relates to coated substrates useful in catalytic converters. The coated substrates can have two washcoat layers, and in some embodiments, the first washcoat layer is divided into two zones. The substrates can be used in catalytic converters and emission control systems for treatment of exhaust gases from gasoline engines.

A CO slip catalyst, for treating an exhaust gas from a lean burn internal combustion engine, is disclosed. The CO slip catalyst comprises palladium and a ceria-containing material. The invention also includes a method for oxidizing excess CO in an exhaust gas, wherein the excess CO results from the periodic contact of an upstream catalyst under rich exhaust conditions. The method comprises contacting the excess CO in the exhaust gas with a CO slip catalyst at a temperature in the range of 100 to 700 C.

An object of the present invention is to provide an exhaust gas catalyst that can achieve high purification performance. The exhaust gas catalyst includes: a base material (3) having a plurality of inner wall surfaces (7) formed by a plurality of through holes (5) penetrating therethrough from a first end surface (3a) to a second end surface (3b); and a plurality of catalyst layers (9) formed on the plurality of inner wall surfaces (7), respectively, wherein: each of the through holes (5) has a central axis (5X); each of the catalyst layers (9) is sectioned into a first region (9A) extending from the first end surface (3a) toward the second end surface (3b) by a predetermined distance, a second region (9B) extending from the second end surface (3b) toward the first end surface (3a) by a predetermined distance, and a third region (9C) placed between the first region (9A) and the second region (9B); and the catalyst layer (9) is formed such that a distance (h1) from the central axis (5X) of the through hole (5) to an inner surface (9m) of the catalyst layer (9) in the first region (9A) of the catalyst layer (9) is smaller than a distance (h3) from the central axis (5X) of the through hole (5) to the inner surface (9m) of the catalyst layer (9) in the third region (9C) of the catalyst layer (9), but is larger than a distance (h2) from the central axis (5X) of the through hole (5) to the inner surface (9m) of the catalyst layer (9) in the second region (9B).

The present disclosure relates to a substrate containing passive NO.sub.x adsorption (PNA) materials for treatment of gases, and washcoats for use in preparing such a substrate. Also provided are methods of preparation of the PNA materials, as well as methods of preparation of the substrate containing the PNA materials. More specifically, the present disclosure relates to a coated substrate containing PNA materials for PNA systems, useful in the treatment of exhaust gases. Also disclosed are exhaust treatment systems, and vehicles, such as diesel or gasoline vehicles, particularly light-duty diesel or gasoline vehicles, using catalytic converters and exhaust treatment systems using the coated substrates.

Provided is a new catalyst that can have heightened purification performance for NOx under lean conditions. Proposed is an exhaust gas purification catalyst composition provided with: a carrier (A) comprising zirconium phosphate; a catalyst active component (a) supported on the carrier (A); a carrier (B) comprising an inorganic oxide porous body; and a catalyst active component (b) supported on the carrier (B).

The present disclosure relates to a substrate comprising nanomaterials for treatment of gases, washcoats for use in preparing such a substrate, and methods of preparation of the nanomaterials and the substrate comprising the nanomaterials. More specifically, the present disclosure relates to a substrate comprising nanomaterial for three-way catalytic converters for treatment of exhaust gases.

Provided are an exhaust gas purifying catalyst having high catalytic activity enabling combustion of PM at low temperatures and free from any risk of dispersal of metal elements arousing concern about environmental load, an exhaust gas purification device and filter having a high combustion efficiency of PM, and a method for producing the catalyst. An exhaust gas purifying catalyst contains: an oxide containing at least one element (A) selected from alkali metals and alkaline earth metals and at least one element (B) selected from Zr, Si, Al, and Ti; and a cesium salt.

A dual-layer catalyst includes a substrate, a first layer disposed on the substrate, and a second layer disposed on the first layer. The first layer includes a first catalyst for storing NO.sub.x when the first catalyst has a temperature below an active temperature of a second catalyst. The first catalyst is to release the stored NO.sub.x when the first catalyst is heated to the active temperature of the second catalyst. The second layer includes the second catalyst for ammonia Selective Catalytic Reduction of the released NO.sub.x. The dual-layer catalyst is to be included in a catalytic converter and a catalyst system for reducing NO.sub.x emissions from a diesel engine, the NO.sub.x emissions including NO.sub.x emitted during a predetermined cold-start time period.

The present invention concerns a process for the production of metal doped cerium compositions comprising a cerium oxide and a metal oxide by precipitation. The invention also concerns metal doped cerium compositions providing high crystallites size and exhibiting high thermal stabilities, which may be used as a catalytic support or for polishing applications.