A catalytic trap ( 10, 110 ) effective for conversion of NO x in an exhaust gas stream is inert to high-temperature reaction with basic oxygenated compounds of lithium, sodium or potassium. The catalytic trap may be substantially free of silica components and may include a catalytic trap material ( 20, 120 ) which contains a refractory metal oxide support, e.g., alumina, having dispersed thereon a catalytic component, such as a platinum group metal catalytic component, and a NO x sorbent comprised of one or more of the basic oxygenated compounds. The catalytic trap material is coated onto a suitable carrier member ( 12, 112 ), such as one made from stainless steel, titanium, alumina, titania, zirconia or silica-leached cordierite. A method of treating a NO x -containing gas stream involves maintaining the gas stream in alternating periods of ( 1 ) lean and ( 2 ) rich or stoichiometric conditions and contacting the gas stream with the catalytic trap under conditions in which NO x is adsorbed during periods of lean operation and released and reduced to nitrogen during periods of rich operation.

Catalytic trap with potassium component and method of using the same

Brennkraftmaschine insbesondere für ein Kraftfahrzeug

A platinum group metal three-way conversion catalyst composition containing a high temperature catalytic component and a low temperature catalytic component has each catalytic component present as separate distinct particles in the same washcoat layer. The catalyst composition is prepared from a washcoat slurry containing a high temperature catalyst support material, and a low temperature catalyst support material, each support material being of sufficiently large particle size so as to prevent each support material forming a solution or a sol with the liquid medium of the slurry. The platinum group metal or metals can be impregnated into each support material either after formation of the washcoat on a non-porous refractory, metallic or pelletised substrate or before forming the washcoat slurry.

Three-way conversion catalysts and methods for the preparation therefor

An exhaust purifier of an internal combustion engine supplies secondary air into an exhaust pipe without cooling nor inactivating an electrically heated catalyst (EHC) that is active. The exhaust purifier includes the EHC 3 disposed in the exhaust pipe 2, a main catalyst 4 disposed in the exhaust pipe 2 downstream from the EHC 3, and a unit for supplying secondary air into the exhaust pipe 2. The secondary air supply unit has a main path 10 for supplying secondary air into a space defined in the exhaust pipe 2 between the EHC 3 and the main catalyst 4 when it is determined that the main catalyst 4 is active. The secondary air supply unit may additionally have a second path 9 for supplying secondary air into the exhaust pipe 2 on the upstream side of the EHC 3 when it is determined that the EHC 3 is active, so that the secondary air may pass through the EHC 3 and reach the main catalyst 4.

Exhaust purifier of internal combustion engine

A corrosion resistant, soft magnetic, ferritic steel alloy, a useful article made therefrom, and a method of using the alloy are described. The alloy has the following composition in weight percent. C - 0.005-0.040; Mn - 1.0 max.; Si - 1.0 max.; P - 0.050 max.; S - 0.020 max.; Cr - 27.0-30.0; Ni - 0.35 max.; Mo - 0.35 max.; Cu - 0.35 max.; Co - 0.25 max.; N - 0.010-0.05. The balance is essentially iron and the usual impurities found in similar grades of ferritic stainless steels. In accordance with another aspect of this invention, there is disclosed a magnetic component for a magnetically actuated device such as a solenoid valve wherein the magnetic component is formed of the aforesaid alloy. In accordance with a further aspect of this invention, there is disclosed a solenoid valve that incorporates a movable magnetic core that is formed of the aforesaid alloy.

Corrosion resistant magnetic alloy an article made therefrom and a method of using same

An exhaust gas purification device comprising a three way catalyst (17), an oxidizing catalyst (20) and a NOx absorbent (23,24) which are arranged in this order in the exhaust passage. A rich air-fuel mixture is burned in the combustion chamber (3), and the exhaust gas discharged from the engine (1) is initially introduced into the three way catalyst (17). Secondary air is fed into the exhaust passage between the three way catalyst (17) and the oxidizing catalyst (20) so that the air-fuel ratio of the exhaust gas flowing into the oxidizing catalyst (20) and the NOx absorbent (23,24) becomes lean.

O Toyota Jidosha K.K. Takeda

Papers

An engine exhaust gas purification device