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 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.

To provide a means removing chlorine gas, which can remove chlorine gas contained in, for example, exhaust gas with high efficiency and does not require frequent exchange. A chlorine gas decomposition catalyst including a metal oxide (X), wherein the metal oxide (X) includes an oxide (X1) of at least one element selected from the group consisting of Ce and Co.

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.

Described is a catalyst composition suitable for use as a selective catalytic reduction catalyst, including small-pore molecular sieve particles having a pore structure and a maximum ring size of eight tetrahedral atoms and impregnated with a promoter metal, and metal oxide particles dispersed within the small-pore molecular sieve particles and external to the pore structure of the small-pore molecular sieve particles, wherein the metal oxide particles include one or more oxides of a transition metal or lanthanide of Group 3 or Group 4 of the Periodic Table. A method for preparing the catalyst, a method for selectively reducing nitrogen oxides, and an exhaust gas treatment system are also described.

The present invention relates to a VOC reduction system and a VOC reduction method that applies pulse type thermal energy to a catalyst to activate the catalyst and oxidizes and removes the VOC.

A phosphor-transition metal-photocatalyst hybrid composite material includes a plurality of beads including a phosphor material, a binder, and zeolite, a plurality of transition metal particles supported on the surface of each of the plurality of beads, and a photocatalyst layer formed on the surface of each of the plurality of beads supporting the transition metal particles by coating a photocatalyst material.

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.

There are provided an exhaust gas-purifying three-way catalyst having a large palladium surface area and excellent in heat resistance and three-way purification performance, easy to produce, and also excellent in productivity, and a method for producing the same, an exhaust gas-purifying catalytic converter, and the like. An exhaust gas-purifying three-way catalyst comprising at least at least one selected from the group consisting of base material particles (A) of a Nd-solid dissolved zirconia-based complex oxide comprising Nd and Zr as constituent metal elements in the following mass proportions in terms of oxides, and base material particles (B) of a La-solid dissolved zirconia-based complex oxide comprising La and Zr, and optionally Nd, as constituent metal elements in the following mass proportions in terms of oxides; and Pd catalyst particles supported on the at least one selected from the group consisting of the base material particles (A) and the base material particles (B), under a reducing atmosphere:

TABLE-US-00001 (Nd-solid dissolved zirconia-based complex oxide) ZrO.sub.2 50 to 75% by mass Nd.sub.2O.sub.3 25 to 50% by mass (La-solid dissolved zirconia-based complex oxide) ZrO.sub.2 50 to 80% by mass La.sub.2O.sub.3 20 to 50% by mass Nd.sub.2O.sub.3 0 to 20% by mass

with a total amount of La.sub.2O.sub.3 and Nd.sub.2O.sub.3 being 20 to 50% by mass.

A composition including cerium and zirconium oxides, including at least 30 wt.-% cerium oxide is desired. Following calcination at a temperature of 900 DEG C. for 4 hours, the composition has two populations of pores, the diameters of the first population being centered around a value of between 5 nm and 15 nm for a composition including 30% to 65% cerium oxide or between 10 nm and 20 nm for more than 65% cerium oxide and the diameter of the second population being centered around a value of between 45 nm and 65 nm for 30% to 65% cerium oxide or between 60 nm and 100 nm for more than 65% cerium oxide.