A high-frequency resonator forming a flow passage for an air induction system, includes an outer shell having a cylindrical inner surface at a first radial distance from a centerline, and an inner shell positioned within the outer shell and forming a volume therebetween. The inner shell includes a first cylindrical outer surface positioned at a second radial distance from the centerline, the first cylindrical outer surface forming an inner surface of the volume and having a first plurality of resonator openings, and a cylindrical support structure having a second cylindrical outer surface positioned at a third radial distance from the axial centerline, and having hydrocarbon adsorber openings. The resonator includes a hydrocarbon adsorber positioned over the cylindrical support structure, such that an inner surface of the hydrocarbon adsorber is exposed to the flow passage through the hydrocarbon adsorber openings. The third radial distance is less than the first radial distance.

A high-frequency resonator forming a flow passage for an air induction system, includes an outer shell having a cylindrical inner surface at a first radial distance from a centerline, and an inner shell positioned within the outer shell and forming a volume therebetween. The inner shell includes a first cylindrical outer surface positioned at a second radial distance from the centerline, the first cylindrical outer surface forming an inner surface of the volume and having a first plurality of resonator openings, and a cylindrical support structure having a second cylindrical outer surface positioned at a third radial distance from the axial centerline, and having hydrocarbon adsorber openings. The resonator includes a hydrocarbon adsorber positioned over the cylindrical support structure, such that an inner surface of the hydrocarbon adsorber is exposed to the flow passage through the hydrocarbon adsorber openings. The third radial distance is less than the first radial distance.

An exhaust aftertreatment system for use with over-the-road vehicle is disclosed. The exhaust aftertreatment system includes a reducing agent mixer with a mixing can and a flash-boil doser configured to inject heated and pressurized reducing agent into the mixing can for distribution throughout exhaust gases passed through the mixing can.

Catalyst for passive NOx absorber to remove NOx from exhaust gas system during engine cold start operation having high storage capacity and ideal desorption properties. The catalyst may include a mixed oxide catalyst system having a Pt promoted Ce.sub.0.5Zr.sub.0.5O.sub.2 catalyst material synthesized by co-precipitation using ammonium carbonate as a precipitation agent.

Systems, apparatuses, and methods include an upstream exhaust analysis circuit structured to determine a characteristic of an exhaust gas stream entering a nitrous oxide (NOx) storage catalyst; a prediction circuit structured to predict a downstream NOx concentration of an exhaust gas stream exiting the NOx storage catalyst based on a model of a NOx storage capacity or a dynamic response of the NOx storage catalyst; a downstream exhaust analysis circuit structured to determine a downstream NOx concentration of the exhaust gas stream exiting the NOx storage catalyst; and a comparison circuit structured to compare the predicted downstream NOx concentration to the determined downstream NOx concentration, and determine a health of the NOx storage catalyst based on the comparison.

An evaporative emission control canister system comprises an initial adsorbent volume having an effective incremental adsorption capacity at 25° C. of greater than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, and at least one subsequent adsorbent volume having an effective incremental adsorption capacity at 25° C. of less than 35 grams n-butane/L between vapor concentration of 5 vol % and 50 vol % n-butane, an effective butane working capacity (BWC) of less than 3 g/dL, and a g-total BWC of between 2 grams and 6 grams. The evaporative emission control canister system has a two-day diurnal breathing loss (DBL) emissions of no more than 20 mg at no more than 210 liters of purge applied after the 40 g/hr butane loading step.

An exhaust gas purification apparatus includes a three-way catalyst. The three-way catalyst includes a downstream catalyst layer and an upstream catalyst layer. The downstream catalyst layer is to be provided in an exhaust pipe. The downstream catalyst layer contains a noble metal material containing at least one of Pd, Rh, or Pt, and an OSC material containing at least ceria. The upstream catalyst layer is to be provided in the exhaust pipe closer to an engine than the downstream catalyst layer is. The upstream catalyst layer contains the noble metal material and the OSC material. The upstream catalyst layer contains the ceria at a content less than a content of the ceria in the downstream catalyst layer.

An exhaust purification system of an internal combustion engine comprises an HC adsorbent 20 arranged adsorbing HC in exhaust gas, an NOx adsorbent 20 adsorbing NOx in exhaust gas, a catalyst 24 removing HC and NOx at a predetermined air-fuel ratio, an air-fuel ratio control part 31 configured to control an air-fuel ratio of exhaust gas, and an HC concentration calculating part 32 configured to calculate a concentration of HC desorbed from the HC adsorbent. A peak of a desorption temperature of HC at the HC adsorbent and a peak of a desorption temperature of NOx at the NOx adsorbent are substantially the same. The air-fuel ratio control part is configured to control an air-fuel ratio of inflowing exhaust gas flowing into the catalyst to the predetermined air-fuel ratio based on the concentration of HC calculated by the HC concentration calculating part when HC is desorbed from the HC adsorbent.

An internal combustion engine in which a fuel reforming operation in a fuel reformation cylinder is not executed and a warming operation for raising the temperature of the fuel reformation cylinder is executed, when a gas temperature of a fuel reformation chamber at a time point when a piston in the fuel reformation cylinder reaches a compression top dead point is estimated to fall short of a reforming operation allowable lower limit gas temperature. For example, EGR gas is introduced to the fuel reformation chamber without cooling the EGR gas. Further, during a predetermined period from the expansion stroke to an exhaust stroke of an output cylinder, exhaust gas warming fuel is supplied to a combustion chamber. Further, the fuel is combusted in the fuel reformation chamber.

An exhaust purification system of an internal combustion engine 50 comprises: an adsorbent 20 adsorbing HC and NOx in exhaust gas, a catalyst 24 removing HC and NOx, an air-fuel ratio control part 31 configured to control an air-fuel ratio of exhaust gas discharged from an engine body of the internal combustion engine to the exhaust passage, and a temperature calculating part 32 configured to calculate a temperature of the adsorbent. At the adsorbent, a desorption temperature of HC is higher than a desorption temperature of NOx. The air-fuel ratio control part is configured to make the air-fuel ratio a stoichiometric air-fuel ratio when a temperature of the adsorbent is in the vicinity of the desorption temperature of NOx, then make the air-fuel ratio leaner than the stoichiometric air-fuel ratio when the temperature of the adsorbent reaches the vicinity of the desorption temperature of HC.