A process for removing hydrocarbons from a feed stream containing hydrocarbons includes introducing ozone to the feed stream to produce an ozone doped stream containing ozone and hydrocarbons, and contacting the ozone doped stream with a supported metal catalyst at a temperature of from 100? C. to 300? C. to produce a treated stream, wherein the supported metal catalyst comprises iron supported on a support selected from aluminosilicates, silica-aluminas, silicates and aluminas. A process for removing NO.sub.x from a feed stream containing NO.sub.x, and an apparatus for removing hydrocarbons and/or NO.sub.x from a feed stream containing hydrocarbons and/or NO.sub.x are also provided.

A method of regenerating an exhaust gas purification filter, in particular for internal combustion engines, uses a vaporized liquid that is to be introduced into the exhaust gas flow. A surface temperature of a heating element in a vaporizer chamber is limited to a maximum of 700 to 750 C.

The present invention relates to three-way conversion catalysts (TWC) for the treatment of an exhaust gas stream comprising nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons (HC), comprising platinum group metal (PGM), a refractory metal oxide support, and a carrier characterized in that the platinum group metal (PGM) comprises platinum, palladium and rhodium, as well as methods and uses thereof.

The invention provides an automotive catalyst composite that includes a catalytic material on a carrier, the catalytic material including a plurality of core-shell support particles including a core and a shell surrounding the core, wherein the core includes a plurality of particles having a primary particle size distribution d.sub.90 of up to about 5 ?m, wherein the core particles include particles of one or more molecular sieves and optionally particles of one or more refractory metal oxides; and wherein the shell comprises nanoparticles of one or more refractory metal oxides, wherein the nanoparticles have a primary particle size distribution d.sub.90 in the range of about 5 nm to about 1000 nm (1 ?m); and optionally, one or more platinum group metals (PGMs) on the core-shell support. The invention also provides an exhaust gas treatment system and related method of treating exhaust gas utilizing the catalyst composite.

Coated gasoline particulate filters (cGPFs) that are produced according to varied material compositions and catalyst configurations are disclosed. The cGPFs include FeCe (rich)-activated Rh compositions that provide greater catalytic functionality. These cGPFs are incorporated within engine systems as components of TWC systems for controlling and reducing engine exhaust emissions. The conversion performance of these TWC systems is assessed and compared employing worldwide harmonized light duty test cycle (WLTC) protocol within a gasoline fueled internal combustion engine. These TWC systems exhibit a significant catalytic performance when compared with the catalytic performance of a PGM-based Original Equipment Manufacturer (OEM) catalyst employed in TWC applications. Further, TWC catalysts are produced including Fe-activated Rh layers comprising dopant elements. The catalytic performance of the TWC catalysts is evaluated by performing light-off and standard isothermal oxygen storage capacity oscillating tests. The TWC catalysts exhibit improved catalytic performance and significant oxygen storage capacity.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate; and a catalytic region on the substrate; wherein the catalytic region comprises a first platinum group metal (PGM) component, an oxygen storage component (OSC) material, a rare earth metal oxide, and an inorganic oxide; and wherein the rare earth metal oxide has an average diameter (d.sub.50) of more than 100 nm.

Described are exhaust gas treatment systems for treatment of a gasoline engine exhaust gas stream containing NOx, particulate matter, and sulfur. The exhaust gas treatment system comprises: one or more catalytic articles selected from a three-way conversion catalyst (TWC), a lean NOx trap (LNT), and an integrated LNT-TWC; a platinum-containing catalytic article downstream from the one or more catalytic articles; and one or more selective catalytic reduction (SCR) catalytic articles immediately downstream from the platinum-containing catalytic article, the one or more SCR catalytic articles including a molecular sieve. The system stabilizes the SCR catalytic article from poisoning by sulfur.

A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprises: a substrate; and a catalytic region on the substrate; wherein the catalytic region comprises a platinum group metal (PGM) component, an oxide, and a rare earth metal component; wherein the oxide is an inorganic oxide, an oxygen storage component (OSC) material, or a mixture thereof; wherein the rare earth metal component concentration by element on the surface of the oxide per unit specific surface area of the oxide is 1 mol/m.sup.2 to 20 mol/m.sup.2.

An exhaust gas purification catalyst, characterized by having a catalyst layer containing palladium, rhodium, and alumina, which supports a sulfate of an alkaline-earth metal selected from barium sulfate and strontium sulfate, and the correlation coefficients .sub.Pd,AE and .sub.Rh,AE calculated from the characteristic X-ray intensity measured using an electron beam micro-analyzer for the palladium, rhodium, and alkaline-earth metal being +0.75 to +1.00 and 0.00 to +0.25, respectively, using 350 points as measurement points obtained by equally dividing the catalyst layer into 351 parts in the thickness direction on a virtual straight line that runs through the catalyst layer in the thickness direction.

An exhaust gas purifying catalyst according to the present invention is provided with a base material 10 and a catalyst-coated layer 30. The catalyst-coated layer 30 is provided with a lower layer 34 and an upper layer 32. The upper layer 32 contains Rh and/or Pt as a noble metal catalyst. The lower layer 34 contains Pd as a noble metal catalyst. The lower layer 34 is provided with a front-stage lower layer 34a positioned on an upstream side and a rear-stage lower layer 34b positioned on a downstream side. The front-stage lower layer 34a is a Ce-free layer that does not contain a Ce-containing oxide. The rear-stage lower layer 34b is a Ce-containing layer that contains a Ce-containing oxide with a pyrochlore structure.