An extruded honeycomb catalyst for nitrogen oxide reduction according to the selective catalytic reduction (SCR) method in exhaust gases from motor vehicles includes an extruded active carrier in honeycomb form having a first SCR catalytically active component and with a plurality of channels through which the exhaust gas flows during operation, and a washcoat coating having a second SCR catalytically active component being applied to the extruded body, wherein the first SCR catalytically active component and the second SCR catalytically active component are each independently one of: (i) vanadium catalyst with vanadium as catalytically active component; (ii) mixed-oxide catalyst with one or more oxides, in particular those of transition metals or lanthanides as catalytically active component; and (iii) an Fe- or a Cu-zeolite catalyst.

A process for producing a ceramic catalyst involves the steps of: a) providing functional particles having a catalytically inactive pore former as a support surrounded by a layer of a catalytically active material, b) processing the functional particles with inorganic particles to form a catalytic composition, c) treating the catalytic composition thermally to form a ceramic catalyst, wherein the ceramic catalyst comprises at least porous catalytically inactive cells which are formed by the pore formers in the functional particles, which are embedded in a matrix comprising the inorganic particles, which form a porous structure and which are at least partly surrounded by an active interface layer comprising the catalytically active material of the layer of the functional particles. An SCR catalyst produced in by this method has an improved NO.sub.x conversion rate compared to a conventionally produced SCR catalyst.

System for the removal of noxious compounds and particulate matter from exhaust gas of a compression ignition engine comprising a three way catalyst unit having an NH.sub.3-SCR activity, an ammonia oxidation activity and an adsorption activity of volatile vanadium and tungsten compounds volatilized off an upstream SCR active catalyst.

Provided is a catalyst composition for treating exhaust gas comprising a blend of a first component and second component, wherein the first component is an aluminosilicate or ferrosilicate molecular sieve component wherein the molecular sieve is either in H+ form or is ion exchanged with one or more transition metals, and the second component is a vanadium oxide supported on a metal oxide support selected from alumina, titania, zirconia, ceria, silica, and combinations thereof. Also provided are methods, systems, and catalytic articles incorporating or utilizing such catalyst blends.

A catalyst article for treating a flow of a combustion exhaust gas comprises: a catalytically active substrate comprising one or more channels extending along an axial length thereof through which, in use, a combustion exhaust gas flows, the one or more channels having a first surface for contacting a flow of combustion exhaust gas; wherein the substrate is formed of an extruded vanadium-containing SCR catalyst material, wherein a first layer is disposed on at least a portion of the first surface, wherein the first layer comprises a washcoat of an ammonia slip catalyst composition comprising one or more platinum group metals supported on a particulate metal oxide support material, and wherein a layer comprising a washcoat of SCR catalyst composition is disposed on a surface in the one or more channels, wherein at least the portion of the first surface on which the first layer is disposed comprises a compound of copper, iron, cerium or zirconium or a mixture of any two or more thereof.

Catalyst regeneration processes that include measures for controlling emissions generated during the regeneration are described. The present invention further relates to catalytic processes for producing various chlorinated aromatic compounds that include provisions for controlling emissions during catalyst regeneration.

The invention belongs to the field of nitrogen oxide control in environmental protection science and technology, and particularly relates to the field of regeneration and utilization of SCR denitration catalyst with calcium poisoning, that is a neutral complex cleaning liquid and a regeneration method for denitration catalyst with calcium poisoning. The present invention uses a neutral polyether surfactant as a regeneration and calcium removal reagent to achieve a poisoned catalyst regeneration method with high calcium removal rate, low loss rate of active components and excellent recovery of denitrification activity; wherein the content of the polyether surfactant is in the range of 0.1-1 wt %; by the regeneration method of the present invention, the loading of active components which is required in the conventional regeneration process can be omitted, while the corrosion of equipment and catalyst can be reduced, thus capable of regenerating the denitration catalyst with high efficiency.

A sorbent composition for removing mercury from flue gas is provided. The sorbent composition contains at least a powdered sorbent, an oxidant and a catalyst. Methods of cleaning flue gas are also provided, which includes injecting the sorbent composition into the flue gas, wherein the powdered sorbent has a fifty percent distribution particle size of from about 25 micrometers to about 75 micrometers.

In order to specify a catalytic converter, especially SCR catalytic converter, with maximum catalytic activity, this catalytic converter has at least one catalytically active component and additionally at least one porous inorganic filler component having meso- or macroporosity. The organic porous filler component has a proportion of about 5 to 50% by weight. More particularly, a diatomaceous earth or a pillared clay material is used as the porous inorganic filler component.

A method for the cleaning of exhaust gas from a compression ignition engine, comprising the steps of injecting a first amount of an aqueous urea solution into the gas; in a first mode of operation and at an exhaust gas temperature of between 150 and 220 C. hydrolysing the first amount of urea to ammonia reducing agent in presence of a first catalyst comprising vanadium oxide supported on titania and subsequently removing part of nitrogen oxides contained in the exhaust gas by contacting the gas mixed with the ammonia reducing agent through a second catalyst comprising platinum on titania and/or alumina; and in a second mode of operation and at an exhaust gas temperature above 220 C. removing a part of the nitrogen oxides in presence of the first catalyst and the ammonia reducing agent and subsequently oxidising hydrocarbons, carbon monoxide and remaining amount of the ammonia reducing agent further contained in the exhaust gas by passing the gas through the second catalyst.