An exhaust aftertreatment system includes a cross-flow selective catalytic reduction catalyst. The cross-flow selective catalytic reduction catalyst includes a housing and a substrate assembly. The substrate assembly includes a plurality of first substrate layers defining a plurality of first flow channels and a plurality of second substrate layers defining a plurality of second flow channels. The exhaust aftertreatment system includes a passive NO.sub.x adsorber. The passive NO.sub.x adsorber includes a housing. The housing includes an inlet in exhaust gas receiving communication with the plurality of first flow channels of the cross-flow selective catalytic reduction catalyst. The housing includes an outlet in exhaust gas providing communication with the plurality of second flow channels of the cross-flow selective catalytic reduction catalyst. The passive NO.sub.x adsorber includes a substrate positioned in the housing. The substrate includes a passive NO.sub.x adsorber washcoat.

Methods for exhaust gas purification, including the steps of: attaching an exhaust gas purification catalyst to an exhaust system of an internal combustion engine, and supplying an exhaust gas to the exhaust gas purification catalyst, where the exhaust gas purification catalyst includes an upper layer containing first carrier particles which are particles of an inorganic oxide and rhodium, and a lower layer containing second carrier particles which are particles of an inorganic oxide, the upper layer includes a rhodium-rich portion near the surface of the upper layer on the upstream side of the exhaust gas flow, and the existence range of the rhodium-rich portion is in a range of greater than 50% to 80% of the length of the upper layer from a downstream side end of an exhaust gas flow and of less than 20 μm in the depth direction from an outermost surface of the upper layer.

The present disclosure is directed to an emission treatment system for NO.sub.x abatement in an exhaust stream of an ammonia-fueled engine, the emission treatment system including a selective catalytic reduction (SCR) catalyst disposed on a substrate in fluid communication with the exhaust stream, an oxidation catalyst disposed on a substrate positioned either upstream or downstream of the SCR catalyst and in fluid communication with the exhaust stream and the SCR catalyst, and optionally, one or more adsorption components disposed on a substrate positioned upstream and/or downstream of the SCR catalyst and in fluid communication with the exhaust stream and the SCR catalyst, the adsorption component chosen from low temperature NO.sub.x adsorbers (LT-NA), low temperature ammonia adsorbers (LT-AA), low temperature water vapor adsorbers (LT-WA), and combinations thereof. The disclosure further provides a related method of treatment of an exhaust gas.

Described herein is a process for increasing mass flow of an exhaust gas through a catalytic converter system for a vehicle. The process may comprise determining a centerline and corresponding cumulative centerline bend angle of a first catalytic converter system spanning from an inlet point at a first end of the catalytic converter systems exhaust pipe to an outlet point at a second end of the catalytic converter systems extension pipe. Once determined, the cumulative centerline bend angle may be increased by increasing an individual bend radius of at least one bend within the exhaust pipe and/or within the extension pipe.

An exhaust device discharging exhaust gas from an engine of a ship propulsion machine includes an exhaust passage through which the exhaust gas flows and a catalyst device purifying the exhaust gas. The exhaust passage includes a first exhaust pipe and a second exhaust pipe connected to an outflow side of the first exhaust pipe. The catalyst device includes a metal catalyst including a metal catalyst carrier, an outer shell portion having a tubular shape and accommodating the metal catalyst, and a holding portion provided in the outer shell portion, having a brim shape protruding radially outward beyond an outer circumferential surface of the outer shell portion, and holding the catalyst device. The catalyst device is held in the exhaust passage by the holding portion being sandwiched between an outflow-side end portion of the first exhaust pipe and an inflow-side end portion of the second exhaust pipe.

A heat recovery device includes: a honeycomb structure including an outer peripheral wall having at least one outer peripheral surface, and partition walls arranged on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells each extending from a first end face to a second end face to form a flow path for a first fluid; a thermoelectric conversion element arranged to face the outer peripheral surface of the outer peripheral wall; a cylindrical member that circumferentially covers the honeycomb structure in which the thermoelectric conversion element is arranged; a casing arranged at an interval so as to form a flow path for a second fluid, the casing being arrange on a radially outer side of the cylindrical member; and a pressing member being configured to press the cylindrical member against the thermoelectric conversion element. The cylindrical member has one or more slit portions.

A catalytic converter system having oxygen storage materials is disclosed and methods for determining whether to reactivate oxygen storage materials and monitoring failure events of the oxygen storage materials are also disclosed.

A tubular member for an exhaust gas treatment device according to at least one embodiment of the present invention includes: a tubular main body made of a metal; and an insulating layer formed at least on an inner peripheral surface of the tubular main body. The insulating layer contains glass containing a crystalline substance, and the glass contains silicon, boron, and magnesium.

A tubular member for an exhaust gas treatment device according to at least one embodiment of the present invention includes: a tubular main body made of a metal; and an insulating layer formed at least on an inner peripheral surface of the tubular main body. The insulating layer contains glass, the glass contains barium, and the glass has a content of barium of 5 mol % or more.

In an aspect of the present disclosure, a catalyst includes an oxide containing 5 or more types of rare earth elements and 1 or more types of platinum group elements. The catalyst has a configuration entropy of a cation site determined based on (i) the number of types of the rare earth elements and the platinum group element that can be arranged in the cation site in a crystalline structure of the oxide, and (ii) each proportion of the rare earth elements and the platinum group element of more than 1.7R, where R is a gas constant.