STA-18, a molecular sieve having a SFW structure and containing phosphorus in the framework, is described. STA-18AP (as prepared) can have a lower alkyl amine, such as trimethylamine, and one of 1,6-(1,4-diazabicyclo[2.2.2]octane)hexyl cations (from diDABCO-C6) or 1,7-(1,4-diazabicyclo[2.2.2]octane)heptyl cations (from diDABCO-C7) or 1,8-(1,4-diazabicyclo[2.2.2]octane)octyl cations (from diDABCO-C8) as SDAs. A lower alkyl ammonium hydroxide, such as tetrabutylammonium hydroxide, can be used as a pH modifier for making SAPO STA-18. A calcined product, STA-18C, formed from STA-18AP is also described. Methods of preparing STA-18AP, STA-18C and metal containing calcined counterparts of STA-18C are described along with methods of using STA-18C and metal containing calcined counterparts of STA-18C in a variety of processes, such as treating exhaust gases and converting methanol to olefins are described.

An object of the present invention is to provide an exhaust gas purification catalyst for purifying exhaust gas, in particular, fine composite-metal particles contained therein, and a method for producing the same; the exhaust gas purification catalyst according to the present invention includes fine composite-metal particles containing Rh and Pd, wherein, when the fine composite-metal particles in the exhaust gas purification catalyst are analyzed by STEM-EDX, the average ratio of the amount of Pd with respect to the total amount of Rh and Pd in the fine composite-metal particles is 1.7 atomic % or more and 24.8 atomic % or less.

An object of the present disclosure is to provide an exhaust gas purification catalyst demonstrating superior storage of NOx contained in exhaust gas.

The exhaust gas purification catalyst of the present disclosure has a substrate, a first catalyst layer containing a catalytic metal for NOx reduction and a NOx storage material and formed on the substrate, and a second catalyst layer containing a catalytic metal for NOx oxidation and formed on the first catalyst layer. In the exhaust gas purification catalyst of the present disclosure, the value obtained by dividing the volume of all large pores having a pore volume of 1000 μm.sup.3 or more by the total volume of all medium pores of having a pore volume of 10 μm.sup.3 to 1000 μm.sup.3 in the second catalyst layer is 2.44 or less.

A catalyst for abating a nitrogen oxide includes: a honeycomb substrate including a plurality of cell passages partitioned by a cell barrier rib; and a coating layer positioned on the internal side of the cell passages. The coating layer includes a support including Mg-substituted alumina (MgAl.sub.2O.sub.4), ceria (Ce), and a composite ceria; and Ba and a noble metal catalyst selected from the group consisting of Pt, Pd, Rh and combinations thereof, which are supported on the support. Also provided is a catalyst system for abating a nitrogen oxide includes the coating layer.

Provide is a catalytic converter including a substrate which includes regions having different cell densities, in which exhaust gas purification performance is superior in all the regions of the substrate. A catalytic converter 10 includes catalyst layers in which a noble metal catalyst is supported on a support in surfaces of cell walls 2 of a substrate 1 having a cell structure in a longitudinal direction of the substrate 1 in which gas flows, in which the substrate 1 has a first region 1A having a relatively high cell density and a second region 1B having a relatively low cell density, and a ratio of a thickness of a catalyst layer 3A in the second region 1B to a thickness of a catalyst layer 3 in the first region 1A is in a range of more than 0.95 times and 1.2 times or less.

In an internal combustion engine of the present invention, an exhaust purification catalyst (13) and a hydrocarbon supply valve (15) are disposed in an engine exhaust path, and NO.sub.x contained in exhaust gas is purified by injecting hydrocarbon from the hydrocarbon supply valve (15) at a predetermined cycle. With respect to the injection amount per unit time of the hydrocarbon from the hydrocarbon supply valve (15), there is a difference provided between the first half and the second half of one injection time period, and in the first-half injection time period (Y), the injection amount per unit time of hydrocarbon is made to be less as compared to the second-half injection time period (X).

A layered catalyst composite for the treatment of exhaust gas emissions, effective to provide lean NO.sub.x trap functionality and three-way conversion functionality is described. Layered catalyst composites can comprise catalytic material on a substrate, the catalytic material comprising at least two layers. The first layer comprising rare earth oxide-high surface area refractory metal oxide particles, an alkaline earth metal supported on the rare earth oxide-high surface area refractory metal oxide particles, and at least one first platinum group metal component supported on the rare earth oxide-high surface area refractory metal oxide particles. The second layer comprising a second platinum group metal component supported on a first oxygen storage component (OSC) and/or a first refractory metal oxide support and, optionally, a third platinum group metal supported on a second refractory metal oxide support or a second oxygen storage component.

The present disclosure relates to ECU for an exhaust purging system comprises: a NOx catalyst provided in an exhaust passage; and a second composite sensor detecting an air-fuel ratio in a downstream of the NOx catalyst, the ECU, which performs a routine of a purge control, calculates the sum of values of the reductant that have been supplied to the NOx catalyst since the start of the routine of the purge control, determines whether the sum is greater than or equal to an end determination threshold, determines whether the air-fuel ratio is less than or equal to a predetermined value, and ends the routine of the purge control in response to an earlier one of a first affirmative determination that the sum is greater than or equal to the end determination threshold and a second affirmative determination that the air-fuel ratio is less than or equal to the predetermined value.

A method for removing NO.sub.X from an oxygen-rich exhaust flow produced by a combustion source that is combusting a lean mixture of air and fuel may include passing the oxygen-rich exhaust flow through an exhaust aftertreatment system that includes a NO.sub.X oxidation catalyst that includes perovskite oxide particles, a NO.sub.X storage catalyst, and a NO.sub.X reduction catalyst.

The invention relates to a catalyst system for reducing nitrogen oxides, which comprises a nitrogen oxide storage catalyst and an SCR catalyst, wherein the nitrogen oxide storage catalyst consists of at least two catalytically active washcoat layers on a supporting body, wherein a lower washcoat layer A contains cerium oxide, an alkaline earth compound and/or alkali compound, as well as platinum and palladium, and an upper washcoat layer B, which is arranged over the washcoat layer A, contains cerium oxide, platinum and palladium, and no alkali compound and no alkaline earth compound. The invention also relates to a method for converting NOx in exhaust gases of motor vehicles that are operated by means of engines that are operated in a lean manner.