Abstract: A catalyst system may include a three-way catalyst that may receive exhaust gases from an engine and convert the exhaust gases to first converted exhaust gases. An ammonia slip catalyst may receive the first converted exhaust gases and convert the first converted exhaust gases to second converted exhaust gases. A hydrocarbon oxidation catalyst may receive the second converted exhaust gases and convert the second converted exhaust gases to third converted exhaust gases.

Abstract: A system includes a controller configured to determine if a combustion engine is operating under a desired rich fuel condition. The controller is also configured, if the combustion engine is operating under the desired rich fuel condition, to monitor a catalytic activity within an ASC assembly that converts NH3 within treated exhaust gases from the combustion engine into N2 to determine whether the catalytic activity has been deactivated in the ASC assembly.

Abstract: A system includes a controller. The controller is configured to monitor a catalytic activity within an ASC assembly that converts ammonia (NH3) within a fluid received from a three-way catalyst (TWC) assembly into nitrogen (N2) to determine whether the catalytic activity in the ASC assembly has aged. The controller is configured to adjust a temperature of the fluid flowing into an inlet of the ASC assembly by controlling an amount of oxidant injected via an oxidant injection system into the fluid upstream of the inlet of the ASC assembly based on a determination that the catalytic activity in the ASC assembly has aged.

Abstract: A passive mid bed air injection apparatus for an engine includes a three way catalyst positioned in an exhaust stream of the engine. The three way catalyst reduces NOx, CO and HC from the exhaust stream. The three way catalyst includes an ammonia slip catalyst positioned in the exhaust stream of the engine. The ammonia slip catalyst is positioned downstream from the three way catalyst and oxidizes NH3 and CO from the exhaust stream. The three way catalyst includes an oxygen input disposed between the three way catalyst and the ammonia slip catalyst such that the oxygen input delivers air downstream from the three way catalyst and upstream from the ammonia slip catalyst. The oxygen input receives the air from a charged side of a forced induction device and delivers the air to the exhaust stream entering the ammonia slip catalyst. An associated method also provided.

Abstract: A passive mid bed air injection apparatus for an engine includes a three way catalyst positioned in an exhaust stream of the engine. The three way catalyst reduces NOx, CO and HC from the exhaust stream. The three way catalyst includes an ammonia slip catalyst positioned in the exhaust stream of the engine. The ammonia slip catalyst is positioned downstream from the three way catalyst and oxidizes NH3 and CO from the exhaust stream. The three way catalyst includes an oxygen input disposed between the three way catalyst and the ammonia slip catalyst such that the oxygen input delivers air downstream from the three way catalyst and upstream from the ammonia slip catalyst. The oxygen input receives the air from a charged side of a forced induction device and delivers the air to the exhaust stream entering the ammonia slip catalyst. An associated method also provided.

Abstract: Various embodiments include systems adapted to monitor catalyst deterioration. Some embodiments include a catalyst deterioration detection system including a pre-catalytic converter gas sensor, a post-catalytic converter gas sensor, at least one computing device in communication with the pre-catalytic converter and post-catalytic converter gas sensors, the at least one computing device configured to monitor catalyst deterioration by performing actions including estimating a catalyst gas storage level by comparing a difference between a pre-catalytic converter gas level from the pre-catalytic converter gas sensor and a post-catalytic converter gas level from the post-catalytic converter gas sensor, comparing the estimated catalyst gas storage level to a baseline catalyst gas storage level and determining that the catalyst is deteriorated in response to the baseline catalyst gas storage level exceeding the estimated gas storage level by a threshold difference.

Abstract: A gaseous reductant injection control system for exhaust aftertreatment is disclosed. In one embodiment, a selective catalytic reduction (SCR) catalyst is in fluid communication with an exhaust stream generated from an engine. An oxidation catalyst (OC) is upstream of the SCR catalyst and in fluid communication with the exhaust stream. A gaseous reductant injector is upstream of the SCR catalyst and downstream of the OC and in fluid communication with the exhaust stream. A first gas sensor is upstream of the OC and a second gas sensor is downstream of the SCR catalyst. A controller receives signals representative of gas concentrations detected in the exhaust stream by the first gas sensor and the second gas sensor, and estimates concentrations of nitric oxide (NO) and nitride dioxide (NO2) in the exhaust stream therefrom.