An exhaust gas purification device includes a first catalyst, a bypass pipe, a second catalyst, and a switching controller. The first catalyst is provided in an exhaust pipe. The bypass pipe branches from a first portion of the exhaust pipe. The first portion is located upstream of the first catalyst. The bypass pipe is recoupled to a second portion of the exhaust pipe. The second portion is located upstream of the first catalyst. The second catalyst 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.

Disclosed are a hydrocarbon adsorption and desorption complex showing hydrocarbon adsorption and oxidation performance by controlling the cation ratio in zeolite, and a preparation method therefor. The hydrocarbon adsorption and desorption complex controls a cation ratio to exhibit the excellent hydrocarbon adsorption ability and oxidation performance even at a temperature lower than the catalyst activation temperature, and increases hydrothermal stability of the hydrocarbon adsorption and desorption complex through hydrothermal treatment to exhibit the excellent hydrocarbon adsorption and desorption performance even in a situation where water is present at a high temperature.

A method includes acquiring nitrogen oxide (NOx) data indicative of a first amount of NOx in an exhaust flow exiting an engine and a second amount of NOx in the exhaust flow exiting an exhaust aftertreatment system coupled to the engine where the exhaust aftertreatment system including a selective catalytic reduction (SCR) system including a SCR catalyst; determining a NOx conversion efficiency fault is present within the exhaust aftertreatment system based on the first amount of NOx and the second amount of NOx; monitoring an actual amount of NOx in the exhaust flow downstream of the SCR catalyst; determining an expected amount of NOx downstream of the SCR catalyst; and determining the SCR catalyst is responsible for the NOx conversion efficiency fault in response to the actual amount of NOx differing from the expected amount of NOx by more than a threshold amount.

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.

A method for operating an internal combustion engine includes combusting a fuel and air mixture within a combustion chamber of an internal combustion engine, thereby forming an exhaust gas, passing the exhaust gas out of the combustion chamber, performing a startup procedure, the startup procedure including passing the exhaust gas from the combustion chamber to a storage unit, capturing criteria pollutants of the exhaust gas with the storage unit, passing the exhaust gas from the storage unit to an aftertreatment system, heating the aftertreatment system to an activation temperature with the exhaust gas from the storage unit, and subsequent to heating the aftertreatment system to the activation temperature, performing a secondary procedure, the secondary procedure including passing the exhaust gas from the combustion chamber to the aftertreatment system thereby forming a treated exhaust gas, and passing the treated exhaust gas to the storage unit.

A catalyst system includes an oxygen storage and release material that has at least one compound of the structure YMO.sub.3+δ, where M is selected from Mn, Co, Cu, Ce, Ti, Ni, Zn, Fe and any combination thereof, and where δ is ≥0. The oxygen storage and release material is configured to allow absorption and release oxygen depending on the conditions of a reagent stream such that sufficient oxygen is maintained for the catalytic removal of at least one of incompletely combusted hydrocarbons, CO, and NO. The catalyst system is useful in a catalytic converter such that oxygen is supplied under rich combustion conditions in an engine upstream of the catalytic converter inlet and oxygen is adsorbed and absorbed under lean rich combustion conditions in the engine.

Methods and systems for operating an engine with a pump that is driven via the engine are described. In one example, start of opening of an injector that supplies a fluid to an engine exhaust system is timed based on a period of the pump so that the output of the fluid injector may be repeatable in the presence of fluid pressure oscillations that are periodic with pump rotation.

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.

Disclosed are a mixed oxide composition based on zirconium and cerium exhibiting a high reducibility, the process for preparing it and its use in the field of catalysis.

A gasoline engine exhaust gas purification catalyst for purifying exhaust gas emitted from a gasoline engine includes a precious metal, alumina, and a ceria/zirconia composite oxide supported on a three-dimensional structure, and has pores having a peak 1 at a pore size of not less than 0.001 μm and not greater than 0.05 μm, pores having a peak 2 at a pore size of not less than 2.5 μm and not greater than 5.0 μm, and pores having a peak 3 at a different pore size than the above pore sizes in a pore size distribution measured by mercury intrusion method, wherein the pore volume of the pores having the peak 3 is greater than 1.4% of the total pore volume. A production method for the catalyst, and an exhaust gas purification method using the catalyst are also described.