Provided are catalyst particles for treating vehicle exhaust gas, containing semiconductor nanoparticles supported by noble metals.

A low-temperature NO.sub.x storage catalyst for automobile exhaust purification and a preparation method thereof. Loading a noble metal salt solution on molecular sieve by equal volume impregnation method, wherein the noble metal salt solution comprises palladium nitrate and platinum nitrate, and the molecular sieve comprises SSZ, SAPO and BETA, then drying at 60-120° C. for 2-6 h, roasting at 500-550° C. in air for 2-5 h, and further roasting at 750-850° C. in air for 2-5 h, and then mixing with aluminum sol, ball milling and pulping, and then coating the slurry on a carrier, wherein the loading on the coating is 100-250 g/L and the noble metal content is 10-150 g/ft.sup.3, drying at 60-120° C. for 2-6 h, then roasting at 500-550° C. in air for 2-5 h, and further continuing roasting at 750-850° C. in air for 2-5 h, to obtain the catalyst. Loading the noble metals Pt and Pd into a pore channel of a molecular sieve improves NO.sub.x storage capacity of a catalyst at low temperatures, and selecting a different type of molecular sieve as an NO.sub.x storage unit and increasing a roasting temperature of a molecular sieve material on which Pt and Pd are loaded significantly increases NO.sub.x storage capacity.

In accordance with the technology herein disclosed, an exhaust gas purification catalyst exhibiting a high exhaust gas purifying performance using a new rare earth-containing material is provided. The exhaust gas purification catalyst herein disclosed includes a base material and a catalyst layer formed on the surface of the base material. The catalyst layer of such an exhaust gas purification catalyst includes rare earth-carrying alumina 50 including a primary particle of a rare earth particle 40 including at least one rare earth element carried on the surface of an alumina carrier 30 including alumina, and the average particle diameter D.sub.50 based on TEM observation of the rare earth particle 40 in the rare earth-carrying alumina 50 is 10 nm or less. As a result of this, it is possible to provide an exhaust gas purification catalyst having high NOx adsorption performance and CO adsorption performance

The present disclosure generally provides a catalyst composition comprising a zeolite containing iron and/or copper with a reduced amount of extra-framework aluminum. The catalyst composition is useful to catalyze the reduction of nitrogen oxides in exhaust gas in the presence of a reductant.

The invention relates to a method for producing a wall-flow filter for removing fine particulate solids from gases, and to the use thereof for cleaning exhaust gases of an internal combustion engine. The invention also relates to a correspondingly produced exhaust-gas filter having a high filtration efficiency.

A three-dimensional porous catalyst, catalyst carrier or absorbent structure of stacked strands of catalyst, catalyst carrier or absorbent material, composed of layers of spaced-apart parallel strands, wherein parallel strands within a layer are arranged in groups of two or more closely spaced-apart, equidistant strands separated by a small distance, wherein the groups of equidistant strands are separated from adjacent strands or adjacent groups of strands by a larger distance.

A method of coating a substrate with a foam is described. The method comprises: (a) introducing a foam into a substrate comprising a plurality of channels through open ends of the channels at a first end of the substrate; and (b) applying at least one of (i) a vacuum to open ends of the channels at a second end of the substrate and (ii) a pressure to the open ends of the channels at the first end of the substrate; wherein the foam comprises a particulate material, and wherein the foam is particle stabilized.

An emissions control device for treating or removing pollutants from an exhaust gas produced by an internal combustion engine is disclosed. The emissions control device comprises a solid foam layer disposed on a substrate, wherein the solid foam layer disposed on a substrate has an open cell structure and comprises a particulate material which is a catalytic material comprising a catalytically active metal supported on a support material.

An exhaust gas filter purifies exhaust gas containing particulate matter emitted from an engine. The filter has cell walls and cells surrounded by the cell walls. Through pores formed in the cell walls, adjacent cells are communicated. The cells have open cells opening along an axial direction of the filter, and plugged cells. An upstream end part of the plugged cell is plugged by a plug member. On a cross section perpendicular to the axial direction, a flow-passage sectional area of the plugged cells is larger than a flow-passage sectional area of the open cells. A total length of the filter is not less than a first standard value and is not more than a critical length Lm determined by respective predetermined equations.

A method of coating a substrate with a foam is described. The method comprises: (a) introducing a foam into a substrate comprising a plurality of channels through open ends of the channels at a first end of the substrate; and (b) applying at least one of (i) a vacuum to open ends of the channels at a second end of the substrate and (ii) a pressure to the open ends of the channels at the first end of the substrate; wherein the foam comprises a particulate material, and wherein the foam is particle stabilized.