A continuous process for preparing a zeolitic material comprising (i) preparing a mixture comprising a source of YO.sub.2, optionally a source of X.sub.2O.sub.3, and a liquid solvent system; (ii) continuously feeding the mixture prepared in (i) into a continuous flow reactor at a liquid hourly space velocity in the range of from 0.3 to 20 h.sup.−1 for a duration of at least 1 h; and (iii) crystallizing the zeolitic material from the mixture in the continuous flow reactor, wherein the mixture is heated to a temperature in the range of from 100 to 300° C.; wherein the volume of the continuous flow reactor is in the range of from 150 cm.sup.3 to 75 m.sup.3, as well as to zeolitic materials which may be obtained according to the inventive process and to their use.

The present invention relates to a selective catalytic reduction catalyst for the treatment of an exhaust gas of a diesel engine comprising: a flow-through substrate comprising 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 coating disposed on the surface of the internal walls of the substrate, wherein the coating comprises a non-zeolitic oxidic material comprising manganese and one or more of the metals of the groups 4 to 11 and 13 of the periodic table, and further comprises one or more of a vanadium oxide and a zeolitic material comprising one or more of copper and iron.

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.

An after treatment system (ATS) for a vehicle having an ATS module includes, fluidly connected in series, an inlet, a Diesel Oxidation Catalysts (DOC), a urea mixer and a Selective Catalytic Reduction (SCR), and an outlet. The inlet is fluidly connected to an output of an engine of the vehicle and the outlet is fluidly connected to an outlet tube of the vehicle. The inlet, DOC, mixer, SCR and outlet are arranged to define a substantial rectangular path of a flow (F) of exhaust gases flowing in the ATS, with the inlet and the outlet being positioned at a same vertex of the substantial rectangular path of the flow (F).

Various embodiments include a diesel engine comprising: an exhaust gas line; a diesel particulate filter arranged in the exhaust gas line; a first NO sensor arranged in the exhaust gas line upstream of the diesel particulate filter; and a second NO sensor arranged in the exhaust gas line downstream of the diesel particulate filter.

A monolith filter unit for exhaust gas cleaning combines urea hydrolysis with particle filtering.

The invention provides a method of synthesizing a zeolite having the CHA crystalline framework, the method including forming a reaction mixture comprising an alumina source comprising a zeolite having an FAU crystalline framework, a silica source, and an organic structure directing agent, the reaction mixture—having a combined molar ratio of M/Si+R/Si higher than the molar ratio OH/Si, wherein M is moles of alkali metal and R is moles of organic structure directing agent; and crystallizing the reaction mixture to form a product zeolite having the CHA crystalline framework, wherein the product zeolite has a mesopore surface area (MSA) of less than about 25 m.sup.2/g. The invention also includes catalyst articles made using the product zeolite, exhaust gas treatment systems including the catalyst articles, and methods of treating exhaust gas using the catalyst articles.

A microporous crystalline material having a molar silica to alumina ratio (SAR) ranging from 10 to 15 and a fraction of Al in the zeolite framework of 0.63 or greater is disclosed. A method of selective catalytic reduction of nitrogen oxides in exhaust gas that comprises contacting exhaust gases, typically in the presence of ammonia, urea, an ammonia generating compound, or a hydrocarbon compound, with an article comprising the disclosed microporous crystalline is also disclosed. Further, a method of making the disclosed microporous crystalline material is disclosed.

Various embodiments include methods for determining the efficiency of an SCR catalytic converter in a system including a nitrogen oxide sensor, and a metering device for a reducing agent arranged in an exhaust-gas duct, and an exhaust recirculation line with a recirculation valve disposed downstream of the SCR catalytic converter and feeding an intake region of the engine. The methods comprise: setting or identifying a quasi-steady-state operating state and an associated recirculation rate; adding a first quantity of reducing agent using the metering device; measuring a resulting first nitrogen oxide value using the sensor; adding a further predefined quantity, different from the first quantity; measuring the resulting nitrogen oxide values using the sensor; and determining the efficiency of the SCR catalytic converter based at least in part on the associated exhaust-gas recirculation rate and the measured nitrogen oxide values.

A honeycomb filter includes a plugged honeycomb structure body which has cell rows arranged along one direction in a cross section of the honeycomb structure body and including a first cell row in which at least the inflow cells are included and in which in the cross section perpendicular to the extending direction of the cells, a through channel area SA occupied by the inflow cells is larger than a through channel area SB occupied by the outflow cells, and a second cell row in which at least the outflow cells are included. A width P1 (mm) of the first cell row, a width P2 (mm) of the second cell row and a curvature radius R (μm) of a curved shape of corner portions of a polygonal shape of each cell satisfy a relation of Equation (1) below: Equation (1): 0.4≤(R/1000)/((P1+P2)/2)×100≤20.