Provided is an exhaust gas purification catalyst having an improved catalyst performance while securing an OSC in an air-fuel ratio (A/F) rich atmosphere where HC poisoning is likely to occur. The present disclosure relates to an exhaust gas purification catalyst including a substrate and a catalyst coating layer coated on the substrate. The catalyst coating layer has an upstream coat layer formed from an end portion in an upstream side with respect to an exhaust gas flow direction in the exhaust gas purification catalyst and a downstream coat layer formed from an end portion in a downstream side with respect to the exhaust gas flow direction in the exhaust gas purification catalyst. The downstream coat layer includes Rh as a catalytic metal, alumina-ceria-zirconia complex oxide, and alkaline earth metal.

A method of controlling a heating element for providing heat to a catalyst of a catalytic converter, the method comprising: determining a catalyst performance characteristic as a function of time, and varying the amount of heating provided by the heating element in response to a change in the catalyst performance characteristic being greater than a predetermined amount.

A method (200) for ascertaining a catalytic converter state is proposed, wherein an exhaust-gas catalytic converter (130) is monitored on the basis of a catalytic converter model. Here, the catalytic converter model is adapted (250) in a manner dependent on measured values detected by means of one or more sensors (145, 147), wherein a frequency and/or a degree of the adaptation of the catalytic converter model is detected (260). The catalytic converter state is ascertained (270) as non-critical if the frequency and/or the degree of the adaptation do not exceed a predeterminable threshold value or is ascertained (270) as critical if the frequency and/or the degree of the adaptation exceed the predeterminable threshold value.

Catalyst for oxygen storage capacity applications that include a zinc doped manganese-iron spinel mixed oxide material. The zinc doped manganese-iron spinel mixed oxide material may be synthesized by a co-precipitation method using a precipitation agent such as sodium carbonate and exhibits a high oxygen storage capacity.

Provided is a porous structure for exhaust purification catalysts having excellent light-off temperature characteristics. The porous structure for exhaust purification catalysts includes an oxygen storage component and an inorganic porous solid. The porous structure has a pore volume distribution such that the ratio of the pore volume of pores with a diameter of from 15 nm to less than 25 nm to the pore volume of pores with a diameter of from 5 nm to less than 15 nm is 1.3 to 2.5 as measured with a mercury porosimeter. The pore volume distribution preferably has at least one peak top in a pore diameter range of from 15 nm to less than 25 nm.

An exhaust purification system of the internal combustion engine, is provided with: an exhaust purification catalyst having a catalytic function; a particulate filter arranged at a downstream side from the exhaust purification catalyst; an oxygen feed device feeding gas containing oxygen into exhaust gas flowing into the particulate filter; a detection device detecting a concentration of ammonia in exhaust gas flowing out from the particulate filter; and a control device. The control device controls the oxygen feed device so as to feed oxygen from the oxygen feed device to the particulate filter if a temperature of the exhaust purification catalyst is equal to or greater than an activation temperature and an air-fuel ratio of exhaust gas is a rich air-fuel ratio, and estimates the amount of deposition of particulate matter on the particulate filter based on the output of the detection device when feeding oxygen.

An exhaust purification system of an internal combustion engine includes a catalyst arranged in an exhaust passage of the internal combustion engine and able to store oxygen, a storage amount calculating part configured to calculate an oxygen storage amount of the catalyst, a poisoning amount calculating part configured to calculate a poisoning amount of the catalyst, and an oxygen amount control part configured to control an amount of oxygen supplied to the catalyst based on the oxygen storage amount and the poisoning amount.

This disclosure is directed to catalyst compositions, catalytic articles for purifying exhaust gas emissions and methods of making and using the same. In particular, the disclosure relates to a catalytic article including a catalytic material on a substrate, wherein the catalytic material has a first layer and a second layer. The first layer provides effective lean NO.sub.x trap functionality and the second layer provides effective three-way conversion of carbon monoxide, hydrocarbons, and nitrogen oxides (NO.sub.x).

A catalyst article for treating exhaust gas from a gasoline engine comprising: a substrate comprising an inlet end, an outlet end with an axial length L; a first catalytic region beginning at the inlet end and extending for less than the axial length L, wherein the first catalytic region comprises a first PGM component and a first inorganic oxide; a second catalytic region beginning at the outlet end, wherein the second catalytic region comprises a second PGM component, a second oxygen storage capacity (OSC) material, and a second inorganic oxide; wherein the first catalytic region is substantially free of ceria; and wherein the first PGM component is palladium (Pd), platinum (Pt) or a combination thereof.

Provided is a porous structure for exhaust purification catalysts having excellent light-off temperature characteristics. The porous structure for exhaust purification catalysts includes an oxygen storage component and an inorganic porous solid. The porous structure has a pore volume distribution such that the ratio of the pore volume of pores with a diameter of from 15 nm to less than 25 nm to the pore volume of pores with a diameter of from 5 nm to less than 15 nm is 1.3 to 2.5 as measured with a mercury porosimeter. The pore volume distribution preferably has at least one peak top in a pore diameter range of from 15 nm to less than 25 nm.