Provided herein is a catalytic article including a catalytic coating disposed on a substrate, wherein the catalytic coating comprises a bottom coating on the substrate and a top coating layer on the bottom coating layer, one such coating layer containing a platinum group metal on a refractory metal oxide support and the other such coating layer containing a ceria-containing molecular sieve. Such catalytic articles are effective toward treating exhaust gas streams of internal combustion engines and exhibit outstanding resistance to sulfur.

Provided herein is a catalytic article including a catalytic coating disposed on a substrate, wherein the catalytic coating comprises a bottom coating on the substrate and a top coating layer on the bottom coating layer, one such coating layer containing a platinum group metal on a refractory metal oxide support and the other such coating layer containing a ceria-containing molecular sieve. Such catalytic articles are effective toward treating exhaust gas streams of internal combustion engines and exhibit outstanding resistance to sulfur.

A nanostructured porous catalyst for rubber vulcanization, the catalyst comprising a high surface area.

The present disclosure relates to a method for forming a catalyst article comprising: (a) forming a slurry having a solids content of up to 50 wt % by mixing together at least the following components a crystalline molecular sieve in an H.sup.+ or NH.sub.4.sup.+ form, an insoluble active metal precursor and an aqueous solvent at a temperature in the range 10 to 35° C.; (b) coating a substrate with the slurry formed in step (a); and (c) calcining the coated substrate formed in step (b) to form a catalyst layer on the substrate. The present disclosure further relates to a catalyst article, particularly a catalyst article which is suitable for use in the selective catalytic reduction of nitrogen oxides, and to an exhaust system.

The present disclosure recognizes a correlation between zeolitic surface area (ZSA) of a catalyst composition and its catalytic activity. Particularly, the disclosure provides catalyst articles for diesel NO.sub.x abatement, including a substrate and a washcoat layer containing metal-promoted molecular sieves, wherein the zeolitic surface area (ZSA) of the catalyst article is about 100 m.sup.2/g or greater, the volumetric surface area is about 900 m.sup.2/in.sup.3 or greater, and/or the total zeolitic surface area (tZSA) is about 1200 m.sup.2 or greater. The disclosure further relates to methods for evaluating ZSA, volumetric ZSA, and tZSA, e.g., including the steps of coating a catalyst composition comprising metal-promoted molecular sieves onto a substrate; calcining and aging the catalyst composition; determining the ZSA (or volumetric ZSA or tZSA) thereof; and correlating the ZSA (or volumetric ZSA or tZSA) with catalyst composition NO.sub.x abatement activity to determine whether the catalyst composition is suitable for an intended use.

The present disclosure recognizes a correlation between zeolitic surface area (ZSA) of a catalyst composition and its catalytic activity. Particularly, the disclosure provides catalyst articles for diesel NO.sub.x abatement, including a substrate and a washcoat layer containing metal-promoted molecular sieves, wherein the zeolitic surface area (ZSA) of the catalyst article is about 100 m.sup.2/g or greater, the volumetric surface area is about 900 m.sup.2/in.sup.3 or greater, and/or the total zeolitic surface area (tZSA) is about 1200 m.sup.2 or greater. The disclosure further relates to methods for evaluating ZSA, volumetric ZSA, and tZSA, e.g., including the steps of coating a catalyst composition comprising metal-promoted molecular sieves onto a substrate; calcining and aging the catalyst composition; determining the ZSA (or volumetric ZSA or tZSA) thereof; and correlating the ZSA (or volumetric ZSA or tZSA) with catalyst composition NO.sub.x abatement activity to determine whether the catalyst composition is suitable for an intended use.

The present disclosure generally provides catalysts, catalyst articles and catalyst systems including such catalyst articles. In particular, the catalyst composition includes a metal ion-exchanged molecular sieve ion-exchanged with at least one additional metal, which reduces the number of metal centers often present in metal promoted zeolite catalysts. Methods of making and using the catalyst composition are also provided, as well as emission treatment systems including a catalyst article coated with the catalyst composition. The catalyst article present in such emission treatment systems is useful to catalyze the reduction of nitrogen oxides in gas exhaust in the presence of a reductant while minimizing the amount of dinitrogen oxide emission.

The present disclosure generally provides catalysts, catalyst articles and catalyst systems including such catalyst articles. In particular, the catalyst composition includes a metal ion-exchanged molecular sieve ion-exchanged with at least one additional metal, which reduces the number of metal centers often present in metal promoted zeolite catalysts. Methods of making and using the catalyst composition are also provided, as well as emission treatment systems including a catalyst article coated with the catalyst composition. The catalyst article present in such emission treatment systems is useful to catalyze the reduction of nitrogen oxides in gas exhaust in the presence of a reductant while minimizing the amount of dinitrogen oxide emission.

Provided herein is a catalytic article including a catalytic coating disposed on a substrate, wherein the catalytic coating comprises a bottom coating on the substrate and a top coating layer on the bottom coating layer, one such coating layer containing a platinum group metal on a refractory metal oxide support and the other such coating layer containing a ceria-containing molecular sieve. Such catalytic articles are effective toward treating exhaust gas streams of internal combustion engines and exhibit outstanding resistance to sulfur.

The present disclosure recognizes a correlation between zeolitic surface area (ZSA) of a catalyst composition and its catalytic activity. Particularly, the disclosure provides catalyst articles for diesel NO.sub.x abatement, including a substrate and a washcoat layer containing metal-promoted molecular sieves, wherein the zeolitic surface area (ZSA) of the catalyst article is about 100 m.sup.2/g or greater, the volumetric surface area is about 900 m.sup.2/in.sup.3 or greater, and/or the total zeolitic surface area (tZSA) is about 1200 m.sup.2 or greater. The disclosure further relates to methods for evaluating ZSA, volumetric ZSA, and tZSA, e.g., including the steps of coating a catalyst composition comprising metal-promoted molecular sieves onto a substrate; calcining and aging the catalyst composition; determining the ZSA (or volumetric ZSA or tZSA) thereof; and correlating the ZSA (or volumetric ZSA or tZSA) with catalyst composition NO.sub.x abatement activity to determine whether the catalyst composition is suitable for an intended use.