A NO.sub.x trap catalyst is disclosed. The NO.sub.x trap catalyst comprises a noble metal, a NO.sub.x storage component, a support, and a first ceria-containing material. The first ceria-containing material is pre-aged prior to incorporation into the NOx trap catalyst, and may have a surface area of less than 80 m.sup.2/g. The invention also includes exhaust systems comprising the NO.sub.x trap catalyst, and a method for treating exhaust gas utilizing the NO.sub.x trap catalyst.

A catalytic wall-flow filter with improved ammonia emission control, and its use in an exhaust system for gasoline engines, are disclosed. The catalytic wall-flow filter comprises a wall-flow filter substrate; a first catalyst coated on the first plurality of channels, wherein the first catalyst comprises a zeolite; and a second catalyst coated on the second plurality of channels. The second catalyst comprises a platinum group metal (PGM) component, an oxygen storage capacity (OSC) material, and an inorganic oxide support.

A composition of formula
Ce.sub.1-a-b-cN.sub.aM.sub.bD.sub.cO.sub.xI
wherein M stands for one or more elements from the group of alkaline metals, except sodium, N is Bi and/or Sb, D is present, or is not present, and if present is selected from one or more of Mg, Ca, Sr, Ba; Y, La, Pr, Nd, Sm, Gd, Er; Fe, Zr, Nb, Al; a is a number within the range of 0<a0.9, b is a number within the range of 0<b0.3, c is a number within the range of 0<c0.2, a plus b plus c is <1, and x is a number within the range of 1.2x2, and its use for exhaust gas aftertreatment systems of Diesel engines, gasoline combustion engines, lean burn engines and power plants.

An inorganic oxide material doped with nano-rare earth oxide particles that is capable of trapping one or more of NO.sub.x or SO.sub.x at a temperature that is less than 400 C. The nano-rare earth oxide particles have a particle size that is less than 10 nanometers. The catalyst support can trap at least 0.5% NO.sub.2 at a temperature less than 350 C. and/or at least 0.4% SO.sub.2 at a temperature less than 325 C. The catalyst support can trap at least 0.5% NO.sub.2 and/or at least 0.2% SO.sub.2 at a temperature that is less than 250 C. after being aged at 800 C. for 16 hours in a 10% steam environment. The catalyst support exhibits at least a 25% increase in capacity for at least one of NO.sub.x or SO.sub.x trapping at a temperature that is less than 400 C. when compared to a conventional rare earth doped support in a 10% steam environment.

This disclosure is directed to catalyst compositions, catalytic articles for purifying exhaust gas emissions and methods of making and using the same. In particular, the disclosure relates to a catalytic article including a catalytic material on a substrate, wherein the catalytic material has a first layer and a second layer. The first layer provides effective lean NO.sub.x trap functionality and the second layer provides effective three-way conversion of carbon monoxide, hydrocarbons, and nitrogen oxides (NO.sub.x).

An oxidation catalyst composite, methods, and systems for the treatment of exhaust gas emissions from a diesel engine are described. More particularly, an oxidation catalyst composite including a first washcoat comprising a zeolite, Pt, and first refractory metal oxide support containing manganese, a second washcoat comprising a second refractory metal oxide support, a Pt component and a Pd component, and a third washcoat comprising palladium and a rare earth oxide component is described.

A NO.sub.x adsorber catalyst composition, 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 composition a support material and one or more platinum group metals disposed on the support material, wherein the support material comprises a mixed dopant NO.sub.x storage enhancer.

A method for preparing a metal-organic framework (MOF) comprising contacting one or more of a rare earth metal ion component with one or more of a tetratopic ligand component, sufficient to form a rare earth-based MOF for controlling moisture in an environment. A method of moisture control in an environment comprising adsorbing and/or desorbing water vapor in an environment using a MOF, the MOF including one or more of a rare earth metal ion component and one or more of a tetratopic ligand component. A method of controlling moisture in an environment comprising sensing the relative humidity in the environment comprising a MOF; and adsorbing water vapor on the MOF if the relative humidity is above a first level, sufficient to control moisture in an environment.

An object of the present invention is to provide a CeO.sub.2ZrO.sub.2-based complex oxide having a sufficiently reduced particle size and a method for producing the CeO.sub.2ZrO.sub.2-based complex oxide, and there are provided a complex oxide containing a zirconium element, a cerium element, and optionally another rare earth metal element, wherein D.sub.50 and D.sub.90 of the complex oxide measured by a laser diffraction scattering particle size distribution measurement method are 0.5 ?m or less and 1 ?m or less, respectively, and a method for producing the complex oxide.

A method for preparing a metal-organic framework (MOF) comprising contacting one or more of a rare earth metal ion component with one or more of a tetratopic ligand component, sufficient to form a rare earth-based MOF for controlling moisture in an environment. A method of moisture control in an environment comprising adsorbing and/or desorbing water vapor in an environment using a MOF, the MOF including one or more of a rare earth metal ion component and one or more of a tetratopic ligand component. A method of controlling moisture in an environment comprising sensing the relative humidity in the environment comprising a MOF; and adsorbing water vapor on the MOF if the relative humidity is above a first level, sufficient to control moisture in an environment. The examples relate to a MOF created from 1,2,4,5-Tetrakis(4-carboxyphenyl)benzene (BTEB) as tetratopic ligand, 2-fluorobenzoic acid and Y(NO3)3, Tb(NO3)3 and Yb(NO3)3 as rare earth metals.