Provided are: a hydrocarbon adsorbent capable of adsorbing hydrocarbons, storing the adsorbed hydrocarbons up to a relatively high temperature, and desorbing the adsorbed and stored hydrocarbons at a relatively high temperature; an exhaust gas purifying catalyst composition using the same; an exhaust gas purifying catalyst; and a method for treating an exhaust gas. The hydrocarbon adsorbent comprises a zeolite having an MRT-type framework structure. The hydrocarbon adsorbent comprises a small-pore zeolite having a total desorption amount ZD.sub.1 of propylene desorbed at 50° C. or higher and lower than 300° C. being 3.5 mmol/g or less and a total desorption amount ZD.sub.2 of propylene desorbed at 300° C. or higher and 500° C. or lower being 0.5 mmol/g or more, per 1 g by mass of the small-pore zeolite, when adsorbing propylene at 50° C. and then heating from 50° C. to 500° C. under the condition of 10° C./min by a temperature-programmed desorption method.

A hydrocarbon adsorbent having high hydrocarbon adsorbing properties even after exposed to a high temperature/high humidity reducing atmosphere, includes a FAU type zeolite having in ESR measurement a spin concentration of a least 1.0 × 10^19 (spins/g) and a ratio of a peak intensity at a magnetic field of at least 260 mT and at most 270 mT to a peak intensity at a magnetic field of at least 300 mT and at most 320 mT of at least 0.25 and at most 0.50 Å and containing bivalent copper. The hydrocarbon adsorbent may be used for a method for adsorbing hydrocarbons to be exposed to a high temperature/high humidity environment, and may be used particularly for a method for adsorbing hydrocarbons in an exhaust gas of an internal combustion engine, such as an automobile exhaust gas.

A composition is provided that has heat resistance sufficient for use as a hydrocarbon adsorbent and desorbs hydrocarbons slowly with respect to an increase in temperature. The composition includes an alkali metal and a zeolite having a YFI structure. A content of the alkali metal is 1 to 40 mass% based on a total mass of the composition, and a content of the zeolite having a YFI structure is 99 to 60 mass% based on the total mass of the composition.

The problem to be solved by the present invention is to provide an oxygen storage and release material comprising a ceria-zirconia-based complex oxide improved in ability to remove HC and NOx and a three-way catalyst able to reduce an amount of NOx emission. Further, to solve this problem, an oxygen storage and release material comprising a ceria-zirconia-based complex oxide containing Gd.sub.2O.sub.3 in 0.1 mol % or more and less than 20 mol % and having an ion conductivity of 2×10.sup.−5 S/cm or more at 400° C. is provided. Further, in addition to the above, an oxygen storage and release material having a molar ratio of cerium and zirconium of 0.2 or more and 0.6 or less by cerium/(cerium+zirconium) and an speed of oxygen storage and release “Δt.sub.50” of 20.0 seconds or more or amount of oxygen storage and release of 300 μmol-O.sub.2/g or more etc. was obtained. Further, by applying the oxygen storage and release material to the catalyst, it is possible to assist the purification of exhaust gas as it changes every instant in accordance with the driving conditions and possible to obtain a catalyst with a higher ability to remove harmful components of catalytic precious metals than before. In particular, it is possible to obtain an automotive exhaust gas purification system excellent in ability to remove CO, NOx, and HC.

The present invention relates to a particulate filter which comprises a wall flow filter of length L and two different catalytically active coatings Y and Z, wherein the wall flow filter comprises channels E and A that extend in parallel between a first and a second end of the wall flow filter and are separated by porous walls which form the surfaces O.sub.E and O.sub.A, respectively, and wherein the channels E are closed at the second end and the channels A are closed at the first end. The invention is characterized in that the coating Y is located in the channels E on the surfaces O.sub.E and the coating Z is located in the channels A on the surfaces O.sub.A.

A method of controlling an evaporative emissions system for a vehicle is provided. A fuel system for a vehicle and a vehicle are also provided. A signal indicative of an entry condition associated with a secondary air flow path for a purge of an evaporative emissions canister is received. A filter is decoupled from a port of the evaporative emissions canister in response to receiving the signal and prior to the evaporative emissions canister purge. The evaporative emissions canister is purged by flowing atmospheric air into the port and through the evaporative emissions canister while the filter is decoupled from the port. The filter is coupled to the port of the evaporative emissions canister after purging the canister.

Provided are an exhaust purification device and an exhaust purification method which can achieve improved fuel efficiency. The exhaust purification device (100) is equipped with: a DOC (5) for occluding hydrocarbons in an exhaust gas; a DPF (6) that is provided downstream from the DOC (5) and is for trapping particulate matter in the exhaust gas; and an ECU (10) for determining, in accordance with the amount of occluded hydrocarbons in the DOC (5), a start time for a regeneration process for removing particulate matter accumulated in the DPF (6).

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 sorption device for filtering evaporation emissions from a fuel tank, includes a vessel, with a first opening connected to an air removal path of the fuel tank and a second opening opening to atmosphere, a middle annular space between a radial outer circumferential boundary of the middle annular space and a radial inner circumferential boundary thereof radially inwardly spaced apart from the outer boundary, a first annular space formed between a radial inner surface of a fluid-tight circumferential outer shell of the vessel, the radial outer boundary being radially inwardly spaced from the inner surface, a sorbent material arranged in the middle annular space, and evaporation emissions from the fuel tank are guided through the first opening into the first annular space, through the sorbent material into a central space of the vessel in the radial direction, and through the second opening to atmosphere or another sorption device.

An exhaust gas purification device includes a first catalyst, a second catalyst, a bypass pipe, a hydrocarbon adsorbent, and a switching controller. The first catalyst is provided in an exhaust pipe. The second catalyst is provided downstream of the first catalyst in the exhaust pipe. The bypass pipe branches from a first portion of the exhaust pipe. The first portion is located upstream of the second catalyst. The bypass pipe is recoupled to a second portion of the exhaust pipe. The second portion is located upstream of the second catalyst. The hydrocarbon adsorbent is provided in the bypass pipe. The switching controller is configured to switch a flow path of an exhaust gas to the bypass pipe based on a deterioration degree of the first catalyst.