A cerium-zirconium-aluminum-based composite material, a cGPF catalyst and a preparation method thereof are provided. The cerium-zirconium-aluminum-based composite material adopts a stepwise precipitation method, firstly preparing an aluminum-based pre-treated material, then coprecipitating the aluminum-based pre-treated material with zirconium and cerium sol, and finally roasting at high temperature to obtain the cerium-zirconium-aluminum-based composite material. The cerium-zirconium-aluminum-based composite material has better compactness and higher density, and when it is used in cGPF catalyst, it occupies a smaller volume of pores on the catalyst carrier, such that cGPF catalyst has lower back pressure and better ash accumulation resistance, which is beneficial to large-scale application of cGPF catalyst.

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 granule reactor (10), an apparatus comprising said reactor and a method implemented by said apparatus are described for treating polluting agents present in industrial gases, particularly but not only, when such gases comprise NO.sub.x, volatile organic compounds (VOCs), carbon monoxide (CO), hydrocarbons and similar pollutants. The pellet reactor is adapted to be used in the treatment of industrial gases, capable of treating industrial gases and removing particulate from said gases while maintaining a constant efficiency. Moreover, a method of treating the polluting agents present in industrial gases by means of said pellet reactor, and a pellet reactor adapted to implement said method of treatment are described.

A pleated filter structure is provided for the removal of gaseous pollutants from a gas mixture to be filtered. The structure comprises an ideally air impervious filter sheet, being pleated so as to form an adjacent series of slit shaped conduits for the passage of air through the structure, each bounded on either side by the folded sections of the filter sheet, these being joined by a series of top creases and bottom creases. The top and/or bottom creases incorporate slit-shaped openings allowing passage of a gas mixture into and/or out of the structure. Gas to be filtered enters through one side of the structure, passes laterally across the filter sheet section surfaces and exits through the other side. Also provided are methods for the manufacture of a pleated filter structure, comprising forming rows of slit-shaped openings in a filter sheet and providing folds, in alternating directions, along the lengthwise extensions of adjacent rows of openings. Methods for filtering a gas are also provided.

Disclosed herein are methods and systems for the removal of volatile organic compounds, carbon monoxide and nitrogen oxides from off-gas, which systems comprise a source of ammonia, means for introducing ammonia into a catalytic article having an SCR functionality; a catalytic article having both an oxidation and an SCR functionality, the catalytic article comprising a catalyst substrate and a catalyst composition comprising at least one platinum group metal and/or at least one platinum group metal oxide, at least one oxide of titanium and at least one oxide of vanadium, wherein the washcoat is located in and/or on the walls of the catalyst substrate: means for measuring the amount of NO.sub.x and/or the ammonia slip between the outlet end of the catalytic article and the stack or at the stack, at least one carbon monoxide source, and means for introducing carbon monoxide into the catalytic article.

Disclosed herein is a system for the removal of volatile organic compounds, carbon monoxide and nitrogen oxides from off-gas even at high NO.sub.2 to NO.sub.x ratios, wherein the amount of NO.sub.2 within NO.sub.x is higher than or equal to 50 mol-%, comprising a source of ammonia, means for introducing ammonia into a catalytic article having an SCR functionality; a catalytic article having both an oxidation and an SCR functionality, the catalytic article comprising a catalyst substrate and a catalyst composition comprising at least one platinum group metal and/or at least one platinum group metal oxide, at least one oxide of titanium and at least one oxide of vanadium, wherein the washcoat is located in and/or on the walls of the catalyst substrate: means for measuring the amount of NO.sub.x and/or the ammonia slip between the outlet end of the catalytic article and the stack or at the stack, at least one carbon monoxide source, and means for introducing carbon monoxide into the catalytic article. Optionally, an SCR catalytic article can be placed upstream of downstream of the cata-lytic article having both an oxidation and an SCR functionality. Also disclosed is a method for the removal of volatile organic compounds, carbon monoxide and nitrogen oxides from off-gas introducing carbon monoxide in order to keep the amount of NOx and/or the ammonia slip between the outlet end of the catalytic article and the stack or at the stack at predetermined values. The method makes use of the system according to the invention. The system and the method can be used for the cleaning of flue gas.

An air treatment unit may include an air inlet to receive a flow of input air for treatment and a reaction reservoir configured to hold an aqueous air treatment solution. The air treatment unit may also include an air dispersing element flow connected with the air inlet, wherein the air dispersing element is configured to convert at least a portion of the flow of input air into a plurality of microbubbles for introduction into the aqueous air treatment solution, such that an amount of one or more target gas species contained within the plurality of microbubbles is reduced through reaction with the aqueous air treatment solution. The unit may include an air outlet configured to output treated air from the reaction reservoir.

An improved cluster-supporting catalyst has heteroatom-removed zeolite particles, and catalyst metal clusters supported within the pores of the heteroatom-removed zeolite particles. A method for producing a cluster-supporting catalyst includes the following steps: providing a dispersion liquid containing a dispersion medium and the heteroatom-removed zeolite particles dispersed in the dispersion medium; and in the dispersion liquid, forming catalyst metal clusters having a positive charge, and supporting the catalyst metal clusters within the pores of the heteroatom-removed zeolite particles through an electrostatic interaction.

A NO.sub.x and SO.sub.x oxidation with atmospheric oxygen to remove NO.sub.x and SO.sub.x from flue gases. The combined system for catalytic oxidation and wet-scrubbing of NO.sub.x and SO.sub.x from a flue gas and manufacturing fertilizers includes: an air separation unit for separating atmospheric oxygen from air and producing an air stream enriched with atmospheric oxygen, an adsorption and oxidation reactor containing an oxidation catalyst and carrying out the catalytic oxidation of NO.sub.x and SO.sub.x by said oxygen to yield nitric and sulphuric acids, a separator and reactor control unit for separation of products and liquids and controlling the reaction; and a vessel containing ammonia streaming said ammonia into the reactor or into the control unit to react with the nitric and sulphuric acids and to yield the fertilizers.

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.