Catalysts having a first catalyst coating and a second catalyst coating, the first catalyst coating including a blend of 1) Pt on a support, and 2) a molecular sieve, and the second catalyst coating including an SCR catalyst.

Catalysts having a first catalyst coating and a second catalyst coating, the first catalyst coating including a blend of 1) Pt on a support, and 2) a molecular sieve, and the second catalyst coating including an SCR catalyst.

The invention proposes a method for the purification of exhaust gases which are generated by a diesel engine with a charging turbine, and a special device for carrying out said method. The device comprises, in the flow direction of the exhaust gas, a dosing device for a reducing agent from a reducing agent reservoir (2), an SCR catalytic converter (3), an oxidation catalytic converter (4) and a diesel particle filter (5). The system is particularly suitable for the purification of the exhaust gases of diesel vehicles in which engines with a turbocharger (charging turbine (1)) and an exhaust-gas recirculation device are used, which engines generate exhaust gases which, in addition to carbon monoxide, hydrocarbons and particles, have nitrogen oxides with an NO.sub.2/NO.sub.X ratio of between 0.3 and 0.7.

An SCR catalyst for treating diesel exhaust gas has: a flow-through substrate with an inlet end, an outlet end, a substrate axial length extending from the inlet end to the outlet end and a plurality of passages defined by internal walls of the flow through substrate extending therethrough; a first coating disposed on the internal wall surface of the substrate, the surface defining the interface between the internal walls and passages, the first coating extending over 40 to 100% of the substrate axial length, the first coating having an 8-membered ring pore zeolitic material with copper and/or iron; a second coating extending over 20 to 100% of the substrate axial length, the second coating having a first oxidic material with titania, wherein at least 75 wt. % of the second coating is titania, calculated as TiO.sub.2, and 0 to 0.01 wt. % of the second coating is vanadium oxides, calculated as V.sub.2O.sub.5.

A catalyst structure for synthesis gas production is used to produce a synthesis gas that includes carbon monoxide and hydrogen. The structure includes a carrier with a porous structure that comprises a zeolite-type compound; first catalyst particles that contain at least one iron-group element selected from the group consisting of nickel, iron, and cobalt; and a second catalyst that contains at least one transition metal element with redox capacity. The carrier includes, inside thereof, mutually communicating passages; the first catalyst particles are present at least in the passages of the carrier; and the second catalyst is present at least in the interior or on an outer surface of the carrier.

SCR-active molecular-sieve based catalysts with improved low-temperature performance are made by heating a molecular-sieve in a non-oxidizing atmosphere with steam (hydrothermal treatment), or in a reducing atmosphere without steam (thermal treatment), at a temperature in the range of 600-900? C. for a time period from 5 minutes to two hours. The resulting SCR-active iron-containing molecular sieves exhibit a selective catalytic reduction of nitrogen oxides with NH.sub.3 or urea at 250? C. that is at least 50% greater than if the iron-containing molecular-sieve were calcined at 500? C. for two hours without performing the hydrothermal or thermal treatment.

SCR-active molecular-sieve based catalysts with improved low-temperature performance are made by heating a molecular-sieve in a non-oxidizing atmosphere with steam (hydrothermal treatment), or in a reducing atmosphere without steam (thermal treatment), at a temperature in the range of 600-900? C. for a time period from 5 minutes to two hours. The resulting SCR-active iron-containing molecular sieves exhibit a selective catalytic reduction of nitrogen oxides with NH.sub.3 or urea at 250? C. that is at least 50% greater than if the iron-containing molecular-sieve were calcined at 500? C. for two hours without performing the hydrothermal or thermal treatment.

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, cella, silica, and combinations thereof. Also provided are methods, systems, and catalytic articles incorporating or utilizing such catalyst blends.

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, cella, silica, and combinations thereof. Also provided are methods, systems, and catalytic articles incorporating or utilizing such catalyst blends.

Disclosed are a tandem catalyst for synthesizing methyl acetate from carbon dioxide, a method for preparing the same, and a method for preparing methyl acetate using the same. The tandem catalyst of the present invention includes a first catalyst having a core-shell structure including a composite metal oxide core and a silica shell surrounding a surface of the composite metal oxide core, and a second catalyst including nano-ferrierite (N-FER) zeolite.