An exhaust-gas purification system of an internal combustion engine includes an electrically heated catalytic device and a three-way catalytic device. The electrically heated catalytic device includes a first honeycomb base having a large number of honeycomb passages and a first catalyst component that is supported on, by a predetermined thin-film treatment, surfaces that define the honeycomb passages and that contains one or more types of noble metals. The three-way catalytic device includes a second honeycomb base having a large number of honeycomb passages and a second catalyst component that is supported on surfaces defining the honeycomb passages and that contains one or more types of noble metals. The total noble metal content per unit volume of the second honeycomb base is higher than the total noble metal content per unit volume of the first honeycomb base.

An exhaust gas heating element comprises a wafer that is substantially cylindrical with an axis and is made of metallic foam. A flexible, electrical insulating sheet covers an edge of the wafer with an overlap on each face of the wafer. A rigid assembly ring, a housing, and two electrodes are also provided. The rigid assembly ring is made from a cylinder trunk, at least a first edge of which is serrated in such a way as to be able to immobilize the wafer and the flexible, electrical insulating sheet in the rigid assembly ring by folding teeth, substantially at 90°.

A method of providing a heating cycle for an after-treatment system is described. The method comprises initiating a pre-charge cycle of a DCDC converter and determining a temperature of the after-treatment system. In response to determining the temperature of the after-treatment system is below a threshold temperature and the pre-charge is complete, the method further comprises operating a solid-state switch to electrically connect a high voltage power source to a heating element to of the after-treatment system, and heating the after-treatment system with the heating element until the after-treatment system reaches the threshold temperature.

A modular exhaust subsystem for purifying an exhaust gas feedstream of a compression-ignition internal combustion engine upstream of a base exhaust aftertreatment system includes a selective catalytic reduction (SCR) catalyst, and a first exhaust gas sensor and a first temperature sensor that are arranged to monitor the SCR catalyst. A reductant delivery system is arranged to inject a reductant upstream of the SCR catalyst. A controller is in communication with an engine-out exhaust gas sensor, a second exhaust gas sensor and a second temperature sensor that are arranged to monitor the base exhaust aftertreatment system. The controller controls the reductant delivery system to inject the reductant into the exhaust gas feedstream upstream of the SCR catalyst based upon inputs from the first and second exhaust gas sensors, the engine-out exhaust gas sensor, and the first and second temperature sensors.

A heater may include: a conductive ceramic cylinder tube in which cell-arrays are concentrically arranged, each cell-array including cells which are arranged in a circumferential direction of the ceramic cylinder tube; an inner electrode electrically coupled to an inner wall portion of the ceramic cylinder tube; and an outer electrode electrically coupled to an outer wall portion of the ceramic cylinder tube. Non-linear portions are radially arranged in the ceramic cylinder tube, each non-linear portion extending in a radial direction of the ceramic cylinder tube while having a plurality of bends or curves between the inner wall portion and outer wall portion of the ceramic cylinder tube. The inner and outer electrodes are provided such that current flows radially at least via said non-linear portions between the inner and outer electrodes.

An automotive exhaust system includes an exhaust pipe and a catalytic converter. The catalytic converter includes a catalyst in fluid communication with the exhaust pipe, and an electric heater between the exhaust pipe and the catalyst. The electric heater includes a cellular structure that defines a plurality of smaller and larger cells. The smaller cells occupy a contiguous half of the cellular structure.

An automotive exhaust aftertreatment system includes a three-way catalyst (TWC) fluidly coupled to an internal combustion engine and a muffler, a selective catalytic reduction (SCR) unit located downstream from the TWC and upstream from the muffler, the SCR unit configured as a NOx catalytic converter and a hydrocarbon (HC) trap, and an electrically heated catalyst (EHC) located downstream from the SCR and upstream from the muffler, the EHC configured as a catalytic converter for the trapped HCs once the HCs are released from the SCR.

A purification device comprises a housing comprising a generally cylindrical wall extending along a longitudinal axis. At least one purification member is arranged in the housing and is intended to be arranged in an exhaust gas flow. The purification device comprises at least one heating element arranged in contact with the purification member, the heating element extending in a plane perpendicular to the longitudinal axis.

An electric circuit for driving a current through a load resistance in a first state and isolating the load resistance in a second state includes: a first switch configured to connect a first terminal of the load resistance and a first port of the electric circuit, the first switch having a first electric potential; a second switch configured to connect a second terminal of the load resistance and a second port of the electric circuit, the second switch having a second electric potential, different from the first electric potential; and at least one auxiliary resistance included within a bypass line configured to bypass the load resistance and the second switch. The first switch is configured to switch a current flowing through the first switch, and the second switch is configured to switch a current flowing through the second switch.

An electrical heating unit H for introduction into the exhaust gas system of an internal combustion engine, in particular upstream with respect to an exhaust gas purification unit, for instance a catalytic converter, which for its operation requires a temperature higher than the ambient temperature, comprises a casing (13) and at least one resistance heating element (14) which is designed as a band and is retained inside the casing (13), wherein the at least one heating band (14) is arranged so that it runs in a meandering pattern and with its flat face parallel or substantially parallel to the longitudinal axis of the casing (13). The heating unit H also comprises at least one support structure (19, 19.1) which is arranged on the end face relative to the heating band (14) and mechanically connected to the casing (13) and has slot-shaped heating band bearings (27) to retain the heating band (14) inside the casing (13), into which slot-shaped heating band bearings (27) the heating band (14) engages by an edge portion and via which support structure (19) the heating band (14) is electrically insulated from the casing (13).