Abstract: Methods are provided for emissions control of a vehicle. In one example, a method for an engine may include, responsive to a plurality of diagnostic entry conditions being met, indicating degradation of a hydrocarbon trap based on an NH3 amount in an exhaust gas. In some examples, the NH3 amount may be determined based on one or more NOx sensor outputs. In some examples, the plurality of diagnostic entry conditions may include the engine having been in operation over an initial duration immediately following an engine cold start. Conditions of the exhaust gas following the engine cold start may be opportunistically utilized in determining the NH3 amount from the one or more NOx sensor outputs. In some examples, the exhaust gas may be actively provided at a predetermined air-fuel ratio to meet at least one of the plurality of diagnostic entry conditions.

Abstract: A hydrocarbon trap is provided for reducing cold-start hydrocarbon emissions. The trap comprises a monolithic flow-through substrate having a porosity of at least 60% and including a zeolite loading of at least 4 g/in3 in or on its walls. A separate coating of a three-way catalyst is provided over the zeolite coating. The trap may further include an oxygen storage material. The hydrocarbon trap may be positioned in the exhaust gas system of a vehicle such that unburnt hydrocarbons are adsorbed on the trap and stored until the monolith reaches a sufficient temperature for catalyst activation.

Abstract: Methods are provided for emissions control of a vehicle. In one example, a method for an engine may include, responsive to a plurality of diagnostic entry conditions being met, indicating degradation of a hydrocarbon trap based on an NH3 amount in an exhaust gas. In some examples, the NH3 amount may be determined based on one or more NOx sensor outputs. In some examples, the plurality of diagnostic entry conditions may include the engine having been in operation over an initial duration immediately following an engine cold start. Conditions of the exhaust gas following the engine cold start may be opportunistically utilized in determining the NH3 amount from the one or more NOx sensor outputs. In some examples, the exhaust gas may be actively provided at a predetermined air-fuel ratio to meet at least one of the plurality of diagnostic entry conditions.

Abstract: Hydrocarbon (HC) traps are disclosed. The HC trap may include a first zeolite material having an average pore diameter of at least 5.0 angstroms and configured to trap hydrocarbons from an exhaust stream and to release at least a portion of the trapped hydrocarbons at a temperature of at least 225° C. The HC trap may also include a second zeolite material having an average pore diameter of less than 5.0 angstroms or larger than 7.0 angstroms. One or both of the zeolite materials may include metal ions, such as transition, Group 1A, or platinum group metals. The HC trap may include two or more discrete layers of zeolite materials or the two or more zeolite materials may be mixed. The multiple zeolite HC trap may form coke molecules having a relatively low combustion temperature, such as below 500° C.

Abstract: A hydrocarbon trap catalyst and method of forming the same are disclosed. The method may include introducing copper into a zeolite at 10% to 75% of an ion-exchange level of the zeolite, introducing at least one of nickel and manganese into a zeolite at 50% to 100% total of an ion-exchange level of the zeolite, and applying a three-way catalyst layer. The copper and nickel and/or manganese may be introduced into a single zeolite or the copper may be introduced into a first zeolite layer and the nickel and/or manganese may be introduced into a second zeolite layer. If copper and another metal are introduced into the same zeolite, copper may be introduced first. The disclosed trap catalyst may increase the release temperature of hydrocarbons such as ethanol, propylene and toluene, and thus reduce vehicle cold start tailpipe emissions.

Abstract: Hydrocarbon (HC) traps are disclosed. The HC trap may include a first zeolite material having an average pore diameter of at least 5.0 angstroms and configured to trap hydrocarbons from an exhaust stream and to release at least a portion of the trapped hydrocarbons at a temperature of at least 225° C. The HC trap may also include a second zeolite material having an average pore diameter of less than 5.0 angstroms or larger than 7.0 angstroms. One or both of the zeolite materials may include metal ions, such as transition, Group 1A, or platinum group metals. The HC trap may include two or more discrete layers of zeolite materials or the two or more zeolite materials may be mixed. The multiple zeolite HC trap may form coke molecules having a relatively low combustion temperature, such as below 500° C.

Abstract: A hydrocarbon trap catalyst and method of forming the same are disclosed. The method may include introducing copper into a zeolite at 10% to 75% of an ion-exchange level of the zeolite, introducing at least one of nickel and manganese into a zeolite at 50% to 100% total of an ion-exchange level of the zeolite, and applying a three-way catalyst layer. The copper and nickel and/or manganese may be introduced into a single zeolite or the copper may be introduced into a first zeolite layer and the nickel and/or manganese may be introduced into a second zeolite layer. If copper and another metal are introduced into the same zeolite, copper may be introduced first. The disclosed trap catalyst may increase the release temperature of hydrocarbons such as ethanol, propylene and toluene, and thus reduce vehicle cold start tailpipe emissions.

Abstract: A hydrocarbon trap is provided for reducing cold-start hydrocarbon emissions. The trap comprises a monolithic flow-through substrate having a porosity of at least 60% and including a zeolite loading of at least 4 g/in3 in or on its walls. A separate coating of a three-way catalyst is provided over the zeolite coating. The trap may further include an oxygen storage material. The hydrocarbon trap may be positioned in the exhaust gas system of a vehicle such that unburnt hydrocarbons are adsorbed on the trap and stored until the monolith reaches a sufficient temperature for catalyst activation.

Abstract: A hydrocarbon trap is provided for reducing cold-start hydrocarbon emissions. The trap comprises a monolithic flow-through substrate having a porosity of at least 60% and including a zeolite loading of at least 4 g/in3 in or on its walls. A separate coating of a three-way catalyst is provided over the zeolite coating. The trap may further include an oxygen storage material. The hydrocarbon trap may be positioned in the exhaust gas system of a vehicle such that unburnt hydrocarbons are adsorbed on the trap and stored until the monolith reaches a sufficient temperature for catalyst activation.

Abstract: A low-temperature catalyst is provided for reducing cold-start hydrocarbon emissions. The catalyst comprises a platinum group metal impregnated onto an oxygen storage material. The catalyst may be used alone or may be included in a hydrocarbon trap containing a hydrocarbon adsorption material therein. The catalyst/hydrocarbon trap is positioned in the exhaust system of a vehicle downstream from a close-coupled catalyst such that the exhaust temperature at the catalyst location does not exceed 850° C. during normal vehicle operation and when combined with a hydrocarbon adsorption material in a trap, the exhaust temperature does not exceed 700° C.

Abstract: A low-temperature catalyst is provided for reducing cold-start hydrocarbon emissions. The catalyst comprises a platinum group metal impregnated onto an oxygen storage material. The catalyst may be used alone or may be included in a hydrocarbon trap containing a hydrocarbon adsorption material therein. The catalyst/hydrocarbon trap is positioned in the exhaust system of a vehicle downstream from a close-coupled catalyst such that the exhaust temperature at the catalyst location does not exceed 850° C. during normal vehicle operation and when combined with a hydrocarbon adsorption material in a trap, the exhaust temperature does not exceed 700° C.

Abstract: A hydrocarbon trap is provided for reducing cold-start hydrocarbon emissions. The trap comprises a monolithic flow-through substrate having a porosity of at least 60% and including a zeolite loading of at least 4 g/in3 in or on its walls. A separate coating of a three-way catalyst is provided over the zeolite coating. The trap may further include an oxygen storage material. The hydrocarbon trap may be positioned in the exhaust gas system of a vehicle such that unburnt hydrocarbons are adsorbed on the trap and stored until the monolith reaches a sufficient temperature for catalyst activation.

Abstract: A hydrocarbon and NOx trap and related apparatus and methods for reducing cold-start NOx emissions from an engine are provided. In one embodiment a trap includes a first, topmost layer, exposed to an exhaust gas flow path of exhaust gases from an engine, the first layer comprising a zeolite, a second layer, substantially covered by the topmost layer, the second layer comprising a NOx adsorbing material and a monolithic substrate, directly supporting the second layer and indirectly supporting the first layer, the substrate providing a substantially rigid structure of the trap. In this way, engine emissions, such as NOx and hydrocarbons may be adsorbed over the exhaust trap at low temperature and then thermally released, limiting cold start emissions beyond engines that only include a lean NOx trap.

Abstract: A hydrocarbon trap is provided for reducing cold-start hydrocarbon emissions. The trap contains an acidic absorption material for improving absorption of low molecular weight hydrocarbons. The acidic absorption materials may be used either alone or in combination with zeolites which are integrated into and/or supported on a monolithic substrate. The hydrocarbon trap may be positioned in the exhaust gas passage of a vehicle such that hydrocarbons are adsorbed on the trap and stored until the engine and exhaust reach a sufficient temperature for desorption.

Abstract: Systems, methods, and computer readable storage media are described in which exhaust gas is routed to a hydrocarbon retaining device during starting, and purged to the engine intake manifold. Various alternative approaches are described for controlling operation and diagnosing degradation. Further, various interrelated configurations are described.

Abstract: Systems, methods, and computer readable storage media are described in which exhaust gas is routed to a hydrocarbon retaining device during starting, and purged to the engine intake manifold. Various alternative approaches are described for controlling operation and diagnosing degradation. Further, various interrelated configurations are described.

Abstract: Methods and systems are provided for operating an engine having a hydrocarbon retaining system and an emission control device coupled to an engine exhaust, the engine exhaust comprising a venturi. One example method comprises, during a storing condition, routing exhaust gas through the venturi without generating a venturi action, and then to the hydrocarbon retaining system, while bypassing the emission control device, to store hydrocarbons in the hydrocarbon retaining system, and during a purging condition, routing exhaust gas through the venturi while generating venturi action, then to the emission control device, and then to the hydrocarbon retaining system, to purge stored hydrocarbons, wherein a flow of purged hydrocarbons is drawn back to the venturi via venturi action.

Abstract: A hydrocarbon trap is provided for reducing cold-start hydrocarbon emissions. The trap is formed by extruding from about 60 to 80% by weight zeolite and from about 20 to 40% by weight of a binder to form an extruded zeolite monolith. A three-way catalyst and an oxygen storage capacity material may also be included in the trap. The hydrocarbon trap contains from about 5.0 to 8.0 g/in.3 zeolite, which provides increased hydrocarbon retention. The hydrocarbon trap may be positioned in the exhaust gas passage of a vehicle such that hydrocarbons are adsorbed on the trap and stored until the monolith reaches a sufficient temperature for catalyst activation.

Abstract: Methods and systems are provided for operating an engine including an exhaust treatment system coupled to an engine exhaust, the exhaust treatment system further coupled to an engine intake via an exhaust gas recirculation (EGR) system. One example method comprises, operating in a first mode including routing exhaust gas through the exhaust treatment system to an exhaust tailpipe; operating in a second mode including routing exhaust gas through the exhaust treatment system to an engine intake via the EGR system, and operating in a third mode including routing exhaust gas to an engine intake through the EGR system while bypassing the exhaust treatment system.

Abstract: A combined hydrocarbon trap/oxidation catalyst system is provided for reducing cold-start hydrocarbon emissions. The hydrocarbon trap includes a monolithic substrate containing zeolite and a catalyst including a mixture of nickel and copper which is impregnated into or washcoated onto the substrate. The hydrocarbon trap may be positioned in the exhaust gas passage of a vehicle such that hydrocarbons are adsorbed on the trap and stored until the engine and exhaust reach a sufficient temperature for desorption and oxidation of the hydrocarbons.