The present description provides high working capacity adsorbents with low DBL bleed emission performance properties that allows the design of evaporative fuel emission control systems that are lower cost, simpler and more compact than those possible by prior art. Emission control canister systems comprising the adsorbent material demonstrate a relatively high gasoline working capacity, and low emissions.

The invention relates to an exhaust gas aftertreatment system for a spark ignition internal combustion engine based on the Otto principle. The internal combustion engine is connected on the outlet side to an exhaust gas system, wherein an electrically heatable three-way catalytic converter, a four-way catalytic converter downstream from the electrically heatable three-way catalytic converter, and a further three-way catalytic converter downstream from the four-way catalytic converter are situated in the exhaust gas system in the flow direction of an exhaust gas through the exhaust gas system. Before the internal combustion engine is started, the electrically heatable three-way catalytic converter and preferably also the four-way catalytic converter are heated to allow efficient exhaust gas aftertreatment of the untreated emissions of the internal combustion engine upon starting the internal combustion engine. The exhaust gas aftertreatment system is also configured to allow efficient conversion of the pollutants also during a regeneration of the four-way catalytic converter, and thus, to ensure particularly low emissions in all operating states of the motor vehicle.

A cold start catalyst is disclosed. The cold start catalyst is effective to adsorb NO.sub.x and hydrocarbons (HC) at or below a low temperature and to covert and release the adsorbed NO.sub.x and HC at temperatures above the low temperature. The cold start catalyst comprises a molecular sieve catalyst and a supported platinum group metal catalyst. The molecular sieve catalyst consists essentially of a noble metal and a molecular sieve. The supported platinum group metal catalyst comprises one or more platinum group metals and one or more inorganic oxide carriers. The invention also includes an exhaust system comprising the cold start catalyst, and a method for treating exhaust gas from an internal combustion engine utilizing the cold start catalyst.

The disclosure relates to a three-way conversion catalyst for the treatment of an exhaust gas comprising nitrogen monoxide, carbon monoxide, and hydrocarbon, wherein the catalyst comprises: (i) a substrate; (ii) a first coating comprising rhodium supported on a first oxidic component; (iii) a second coating comprising palladium supported on a non-zeolitic oxidic material, wherein the non-zeolitic oxidic material comprises manganese and a second oxidic component, wherein the second coating consists of 0 weight-% to 0.001 weight-% of platinum; wherein the first coating is disposed on the substrate over x % of the axial length, with x ranging from 80 to 100; wherein the second coating extends over y % of the axial length from the inlet end to the outlet end and is disposed on the first coating, with y ranging from 20 to x.

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.

Provided is an exhaust gas purification catalyst system comprising, in the following order, from the upstream side of an exhaust gas flow: a first exhaust gas purification catalyst apparatus 100 including a metal honeycomb substrate 110 and a first catalyst coat layer 120 on the metal honeycomb substrate 110; a heater 300; and a second exhaust purification catalyst apparatus 200 including a cordierite honeycomb substrate 210 and a second catalyst coat layer 220 on the cordierite honeycomb substrate 210, wherein the first catalyst coat layer 120 contains an adsorbent 130 that can adsorb one or two or more among NOx, HC and CO, and the second catalyst coat layer 220 contains inorganic oxide particles 230 and catalyst precious metal particles 240 supported on the inorganic oxide particles 230.

The present disclosure discloses an ethylene degradation catalyst and a preparation method and a use thereof.

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 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. 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 BETP butane loading step.

The present description provides high working capacity adsorbents with low DBL bleed emission performance properties that allows the design of evaporative fuel emission control systems that are lower cost, simpler and more compact than those possible by prior art. Emission control canister systems comprising the adsorbent material demonstrate a relatively high gasoline working capacity, and low emissions.