The present disclosure provides an exhaust gas purification catalyst improved in OSC performance while maintaining an exhaust gas purification performance, which comprises a substrate and at least one catalyst layer formed on the substrate, wherein an uppermost catalyst layer contains a catalyst metal, a first OSC material having a pyrochlore structure, and a second OSC material having a higher oxygen storage/release rate than the first OSC material, wherein the uppermost catalyst layer consists of an upstream catalyst layer and a downstream catalyst layer, and wherein a proportion of a mass of the second OSC material based on a total mass of the first OSC material and the second OSC material is in a specific range in each of the upstream catalyst layer and the downstream catalyst layer.

The present technology relates generally to parallel passage contactors having active layers and methods for its use. Particularly, the present technology relates to parallel passage contactors having active layers with sorbents and/or catalysts and methods of use in sorptive gas separation and/or catalytic reactions.

A catalytic 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 a first platinum group metal (PGM) component and a support; a second catalytic region comprising a second PGM component on a support with low ammonia storage and a first SCR catalyst; and wherein the first catalytic region is covered by at least another catalytic region.

An exhaust aftertreatment system includes a cross-flow selective catalytic reduction catalyst. The cross-flow selective catalytic reduction catalyst includes a housing and a substrate assembly. The substrate assembly includes a plurality of first substrate layers defining a plurality of first flow channels and a plurality of second substrate layers defining a plurality of second flow channels. The exhaust aftertreatment system includes a passive NO.sub.x adsorber. The passive NO.sub.x adsorber includes a housing. The housing includes an inlet in exhaust gas receiving communication with the plurality of first flow channels of the cross-flow selective catalytic reduction catalyst. The housing includes an outlet in exhaust gas providing communication with the plurality of second flow channels of the cross-flow selective catalytic reduction catalyst. The passive NO.sub.x adsorber includes a substrate positioned in the housing. The substrate includes a passive NO.sub.x adsorber washcoat.

A catalyst arrangement deciding method for a flue gas denitrizer including a catalyst layer disposed in an exhaust gas passage includes: a step of investigating a location dependence of a degradation state of a catalyst in the catalyst layer after a lapse of a period of operation; and a step of deciding a first region of the catalyst layer in which a first catalyst is used and a second region of the catalyst layer in which a second catalyst different from the first catalyst is used, on the basis of the location dependence.

An oxidation catalyst for treating an exhaust gas produced by a diesel engine comprises a catalytic region and a substrate, wherein the catalytic region comprises a catalytic material comprising: bismuth (Bi) or an oxide thereof; a Group 8 metal or an oxide thereof; a platinum group metal (PGM) selected from the group consisting of (i) platinum (Pt), (ii) palladium (Pd) and (iii) platinum (Pt) and palladium (Pd); and a support material, which comprises alumina, silica, a mixed oxide of alumina and a refractory oxide, a mixed oxide of silica and a refractory oxide, a composite oxide of alumina and a refractory oxide, a composite oxide of silica and a refractory oxide, alumina doped with a refractory oxide or silica doped with a refractory oxide.

A three-way catalyst article, and its use in an exhaust system for compressed natural gas engines, is disclosed. The catalyst article for treating exhaust gas from compressed natural gas (CNG) engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the outlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first zeolite; and a second catalytic region beginning at the inlet end, wherein the second catalytic region comprises a second platinum group metal (PGM) component, a second oxygen storage capacity (OSC) material, and a second inorganic oxide; wherein the second PGM component is selected from the group consisting of palladium, platinum, rhodium or a combination thereof.

Process for the removal of NOx (NO, NO2) and nitrous oxide (N2O) contained in a process off-gas comprising the steps of (a) adding an amount of a NOx reducing agent into the process off-gas;(b) in a first stage passing the process off-gas admixed with the reducing agent through a catalyst active in selective catalytic reduction of NOx with the reducing agent and providing an effluent gas comprising the nitrous oxide and residual amounts of reducing agent; and(c) in a second stage passing the effluent gas through a catalyst comprising a cobalt compound and being active in decomposition of nitrous oxide and oxidation of the residual amounts of the reducing agent.

The present invention discloses a catalyst for in-situ CO2 capture and coupling reduction with biomass oxidation, a preparation method therefor and an application thereof. The catalyst is applied to the coupling reaction of photocatalytic CO2 reduction and biomass oxidation. The preparation of the catalyst is to synthesize layered double hydroxides (LDHs) containing CO32− between layers by using coprecipitation method, hydrothermal method, sol-gel method and the like, wherein the chemical formula is [M1-x2+Mx3+(OH)2]x+(An−)x/n.Math.mH2O, which has a thickness of 20-30 nm and an average particle diameter of 60-90 nm. Then metal ion vacancy defects are produced on LDHs laminate by using a NaOH/KOH selective etching to obtain the corresponding catalyst. The catalyst is used in photocatalytic reaction, characterized in that CO32− is continuously consumed in the reaction process, and the catalyst can absorb CO2 in the air for recovery after the reaction, and can be repeatedly used to continuously consume CO2 in the air, thus realizing the direct capture and effective utilization of CO2.

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.