An exhaust system for a diesel engine is provided. The exhaust system includes a component body with a surface, and a surface treatment disposed on some of the surface or all of the surface. The surface treatment is disposed so as to receive Diesel Exhaust Fluid (DEF) injected into the exhaust system during operation of the diesel engine. The surface treatment facilitates increased heat transfer to the received DEF to promote water evaporation and urea thermolysis of the received DEF.

An after-treatment system includes, in series along an exhaust gas flow direction through the after-treatment system: a diesel oxidation catalyst (DOC), a diesel exhaust fluid (DEF) delivery device, a soot-reducing device and a selective catalytic reduction (SCR) catalyst.

An exhaust system assembly including a catalyst housing, a catalyst core, and a swirler tube positioned inside the catalyst housing. The swirler tube has a plurality of openings that permit radial exhaust flow into an inner volume of the swirler tube from the catalyst housing. One end of the swirler tube has blades that extend inward and include oblique surfaces arranged at oblique angles relative to a centerline axis of the swirler tube. These blades induce a vortex in the exhaust gases exiting the first swirler tube end. The swirler tube is arranged inside the catalyst housing such that a sequential flow path is created where the exhaust gases flowing through the catalyst housing must first pass through the openings in the swirler tube and then by the blades at the first swirler tube end.

A system for reducing ammonia (NH.sub.3) emissions includes (a) a first component comprising a first substrate containing a three-way catalyst, wherein the first component is disposed upstream of a second component comprising a second substrate containing an ammonia oxidation catalyst, wherein said ammonia oxidation catalyst comprises a small pore molecular sieve supporting at least one transition metal; and (b) an oxygen-containing gas input disposed between the components. For example, a CHA Framework Type small pore molecular sieve may be used. A method for reducing NH.sub.3 emission includes introducing an oxygen-containing gas into a gas stream to produce an oxygenated gas stream; and exposing the oxygenated gas stream to an NH.sub.3 oxidation catalyst to selectively oxidize at least a portion of the NH.sub.3 to N.sub.2. The method may further include the step of exposing a rich burn exhaust gas to a three-way catalyst to produce the gas stream comprising NH.sub.3.

The invention relates to an exhaust aftertreatment arrangement (100) for an exhaust system of an internal combustion engine, said exhaust aftertreatment arrangement (100) comprising a fluid passage (30) for exhaust gases from said exhaust system, said fluid passage (30) defining an inner perimeter (32) and an exhaust aftertreatment unit (40) comprising an exhaust aftertreatment element (42) confined by an outer wall (44) defining an outer periphery (46) of the exhaust aftertreatment unit (40), the exhaust aftertreatment unit (40) being sealingly arranged in said fluid passage (30) for enabling flow of said exhaust gases through said exhaust aftertreatment element (42). A leakage treatment member (50) comprising an exhaust aftertreatment component is arranged between said inner perimeter (32) of the fluid passage (30) and said outer periphery (46) of said outer wall (44) of the exhaust aftertreatment unit (40), for aftertreatment of any leakage of said flow of exhaust gases past said aftertreatment unit (40) in said fluid passage (30).

A reductant insertion system for an after treatment system configured to decompose constituents of an exhaust gas, includes: a dry reductant tank configured to contain a dry reductant; a reductant delivery line configured to operatively couple the dry reductant tank to the after treatment system for delivery of the dry reductant to the after treatment system; and a pressurized gas source configured to communicate the dry reductant to the after treatment system through the reductant delivery line using pressurized gas.

A metal oxide catalyst synthesized using supercritical carbon dioxide extraction is provided, wherein the metal oxide catalyst includes an active site containing at least one type of metal oxide and a support for loading the active site and the metal oxide is an oxide of a metal selected from the group consisting of transition metals (atomic number 21 to 29, 39 to 47, 72 to 79, or 104 to 108), lanthanide (atomic number 57 to 71), post-transition metals (atomic number 13, 30 to 31, 48 to 50, 80 to 84, and 112), and metalloids (atomic number 14, 32 to 33, 51 to 52, and 85) in the periodic table, and a combination thereof.

A transition-metal-CHA molecular sieve catalyst and mixed-template synthesis procedure are disclosed.

The present invention relates generally to the field of exhaust treatment systems for purifying exhaust gas discharged from a lean burn engine. The exhaust treatment system comprises a Diesel Oxidation Catalyst (DOC), a Catalyzed Soot Filter (CSF), a reductant injector, an AEI zeolite based Selective Catalyzed Reduction (SCR) catalyst and an Ammonia Oxidation Catalyst (AMOX) downstream to the AEI zeolite based SCR catalyst.

An ammonia slip catalyst having an SCR catalyst and an oxidation catalyst comprising at least two metals, each of which is selected from a specific group, and a substrate upon which at least oxidation catalyst is located is described. The ammonia slip catalyst can have dual layers, with one of the layers containing an SCR catalyst, a second layer containing the oxidation catalyst with comprises at least two metals, each of which is selected from a specific group, and the ammonia slip catalyst does not contain a platinum group metal. Methods of making and using the ammonia slip catalyst to reduce ammonia slip are described.