Abstract: An exhaust gas treatment apparatus and method for its use includes an upstream catalyst and a downstream catalyst. The upstream catalyst contains a catalytic metal effective at least for the oxidation of hydrocarbons in the exhaust gas stream, and preferably contains a palladium catalytic component and contains substantially no oxygen storage components, i.e., oxides of cerium, cobalt, iron, magnesium, molybdenum, nickel, praseodymium, tungsten and vanadium, but the downstream catalyst includes an oxygen storage component. Preferably, the upstream catalyst is a close-coupled catalyst. The downstream catalyst may be an underfloor catalyst or a close-coupled catalyst, in which case there is, preferably, an additional, underfloor catalyst.

Abstract: The present invention relates to a composite of cerium, zirconium and samarium components, a catalyst composition containing such composite and the use of the catalyst composition for the treatment of a gas stream to reduce contaminants contained therein. The catalyst composition has the capability of substantially simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides.

Abstract: A catalyst composition is applied to an interior of a hollow substrate. The composition is coated on the substrate by immersing the substrate into a vessel containing a bath of coating slurry. A vacuum is then applied to the partially immersed substrate. The intensity of the vacuum and its application time is sufficient to draw the coating slurry upwardly from the bath into each of a plurality of channels located in the interior of the hollow substrate. After removing the substrate from the bath, it is rotated 180°. A blast of pressurized air is applied at an intensity and for a time sufficient to distribute the coating slurry within the channels of the substrate to form a uniform coating profile therein.

Abstract: A method for reduction of NOx in a lean gaseous stream includes passing the gaseous stream at a temperature within the NOx sorbing temperature range through a catalyzed trap member having an oxidation catalyst intimately combined with a sorbent material. The sorbed NOx is periodically removed by introducing a combustible component into the gaseous stream and oxidizing it on the trap member to thermally desorb the NOx. The amount of combustible component introduced is limited to maintain the gaseous stream bulk composition lean and to avoid increasing the bulk temperature of the gaseous stream to a temperature which is too high for effective lean NOx abatement treatment. A suitable NOx abatement catalyst is used to reduce the desorbed NOx. Sorbing (trapping) and desorbing periods are alternated, usually in response to the temperature of the gaseous stream, and an apparatus to carry out the process is provided.

Abstract: A catalyst reduction system using diesel fuel as a reductant for vehicles equipped with diesel engines reduces NOx transient emissions produced during acceleration. Impending engine accelerations are sensed to produce metered pulse(s) of fuel oil simultaneously with and preferably in advance of, the NOx transient emission. The fuel pulse is sufficient in quantity to reduce the NOx transient emission when the NOx and HC resulting from the cracked fuel oil are present at spatially equal distances within the reducing catalytic converter. Optionally, the washcoat of the reducing catalyst is formulated to delay the adsorption/desorbtion of one of the gases on the washcoat to assure proper timing of the NOx transient and fuel pulse(s).

Abstract: A process for catalytically generating a hydrogen-rich gas from a hydrocarbon feed. A stream comprising the hydrocarbon feed , water and air is preheated to a temperature sufficiently high to initiate catalytic partial oxidation of the hydrocarbon feed. The preheated stream is then introduced into an autothermal reactor containing a layered catalyst member at a temperature sufficient to initiate and sustain both catalytic partial oxidation and catalytic steam reforming. At least part of the hydrocarbon feed is catalytically partially oxidized to produce a hydrogen-rich gas comprising hydrogen and carbon oxides and hydrocarbons remaining in the feed are steam reformed to produce further quantities of the hydrogen-rich gas. The layered catalyst member comprises a monolith substrate containing at least one layer of a steam reforming catalyst in contact with at least one layer of a catalytic partial oxidation catalyst.

Abstract: A process for the reduction of gaseous sulfur compounds in gaseous streams. The gaseous stream is contacted with a sorber, e.g., zinc oxide, which is cable of sorbing the sulfur compounds under sulfur sorbing conditions. The sorber is present in the form of one or more layers on the surface of a monolith carrier, e.g., cordierite. The layers of the sorber have a total thickness of at least 3 g/in3 of the carrier. The process is especially useful for the removal of gaseous sulfur compounds such as H2S from gaseous streams.

Abstract: Methods and apparatus for reducing the TPM level of a diesel engine exhaust stream by providing a suitable oxidation catalyst into the exhaust train. The oxidation catalyst may be incorporated into a thermal insulative coating on the inner surface of the exhaust train, particularly the exhaust manifold and exhaust pipes prior to the turbocharger. Alternatively, when the exhaust train includes a turbocharger, the catalyst can be in a separate monolithic unit between the engine and the turbocharger. The system may also include an improved diesel oxidation catalyst unit having a metal monolithic substrate. The oxidation catalyst can also be incorporated into a thermal insulative coating inside the cylinders, particularly on non-rubbing surfaces such as The invention also includes the use of a protective mullite top coat on the thermal coating. A further embodiment is the use of a stainless steel bond coat to bind the thermal coating to a metallic substrate, particularly an aluminum substrate.

Abstract: The present invention relates to sulfur tolerant catalyst composites useful for reducing contaminants in exhaust gas streams, especially gaseous streams containing sulfur oxide contaminants. More specifically, the present invention is concerned with improved NOx trap catalysts for use in diesel engines as well as lean burn gasoline engines. The sulfur tolerant NOx trap catalyst composites comprise a platinum component, a support, a NOx sorbent component, and a spinel material prepared by calcining an anionic clay material represented by the formula MmNn(OH)(2m+2n)Aa.bH2O, wherein the formula is defined herein. The sulfur tolerant NOx trap catalyst composites are highly effective with a sulfur containing fuel by trapping sulfur oxide contaminants which tend to poison conventional NOx trap catalysts used to abate other pollutants in the stream.

Abstract: A diesel powered vehicle is provided with an SCR system which uses an external reducing reagent to convert NOx emissions in a manner which accounts for the effects of NOx transient emissions on the reducing catalyst. Actual NOx emissions produced by the engine are filtered using a variable NOx time constant in turn correlated to the reductant/NOx storage capacity of the reducing catalyst at its current temperature to account for changes in the SCR system attributed to NOx transient emissions. Catalyst temperature is filtered using a variable catalyst time constant corresponding to current space velocity of the exhaust gas to account for changes in the catalyst temperature attributed to NOx transient emissions. The reductant is metered on the basis of the filtered, corrected NOx concentration applied at a NSR ratio based, in turn, on the filtered, corrected reducing catalyst temperature.

Abstract: A multi-zoned catalytic trap for conversion of NOx in an exhaust gas stream which emanates from an engine which is operated with periodic alternations between lean, and stoichiometric or rich, conditions. The catalytic trap comprises a first zone, a second zone and, optionally, one or more intermediate zones disposed between the first zone and the second zone. Each of the zones comprises a catalytic trap material coated on a refractory carrier member. In the first zone, the catalytic trap material comprises a refractory metal oxide support having dispersed thereon a palladium catalytic component in the amount of about 30 to about 300 g/ft3, a platinum catalytic component in the amount of 0 to about 100 g/ft3 and a rhodium catalytic component in the amount of 0 to about 10 g/ft3; and a NOx sorbent comprising one or more basic oxygenated compounds of one or more alkaline earth metals and optionally, one or more basic oxygenated compounds of one or more alkali metals.

Abstract: A metal substrate is fabricated and coated with a catalyst for ozone conversion of atmosphere passing through the substrate. A plurality of aluminum foil sheets that have been slit, stretched and twisted into a plurality of regularly repeating channels having geometrically shaped openings are serially positioned one on top the other to form a foil stack with channel openings partially blocked by channel walls of overlying foil sheets. Thicker covers with openings at the top and bottom of the stack form a sandwich and the sandwich pleated to form corrugations in a flexible but rigid sandwich substrate. The channel walls are coated with an ozone depleting catalyst which the ozone atmosphere contacts to remove ozone as the ozone atmosphere travels through the stack construction.

Abstract: A highly reactive reducing gas mixture is produced from vehicle fuel and introduced into the exhaust gas of an internal combustion engine operated at lean burn conditions and passed over a reducing catalyst to convert NOX emissions to benign emissions. Preferably, fuel with oxygen present in a carrier gas is metered into a plasma reactor having a bed of dielectric particles which prevent formation of coke as the fuel is reacted. The plasma induces a number of simultaneous reactions with the fuel to produce a substantial amount of oxygenated and non-oxygenated, unbranched organic molecules at relatively low temperatures that are highly reactive and ideally suited for use as a reducing agent in an SCR catalyst.

Abstract: A composition for abatement of airborne pollution by volatile organic compounds (“VOCs”) has an upstream composition which contains a protective adsorbent, e.g., Y zeolite, which is effective for adsorbing large VOC molecules, e.g., toluene, and a protective oxidation catalyst intimately intermingled therewith. The downstream composition contains a second adsorbent, e.g., a silver-containing ZSM-5, which is effective for adsorbing relatively smaller VOC molecules, e.g., propylene, and a second oxidation catalyst intimately intermingled therewith. Oxidation of VOCs while they are still retained on the adsorbents is promoted at temperatures lower than would be required if the VOCs were desorbed into the gaseous phase. Apparatus is provided including a first contact member (24) coated with the upstream composition and positioned upstream of a second contact member (32) coated with the downstream composition.

Abstract: A catalyst reduction system using diesel fuel as a reductant for vehicles equipped with diesel engines reduces NOx transient emissions produced during acceleration. Impending engine accelerations are sensed to produce metered pulse(s) of fuel oil simultaneously with and preferably in advance of, the NOx transient emission. The fuel pulse is sufficient in quantity to reduce the NOx transient emission when the NOx and HC resulting from the cracked fuel oil are present at spatially equal distances within the reducing catalytic converter. Optionally, the washcoat of the reducing catalyst is formulated to delay the adsorption/desorbtion of one of the gases on the washcoat to assure proper timing of the NOx transient and fuel pulse(s).

Abstract: A low pressure EGR system suitable for use as a passive retrofit system is disclosed for moving vehicles equipped with a diesel engine. The EGR loop inlet is positioned upstream of the exhaust particulate filter and downstream of the turbine to utilize backpressure created by the exhaust particulate filter to insure EGR flow in the loop. A catalyzed soot filter in communication with the EGR pickup insures cleansed EGR gases at the EGR return downstream of the air filter and upstream of the compressor. A corrugated EGR line provides cooling of the EGR gases.

Abstract: A method and apparatus that converts time-resolved sensor signals into frequency domain signals using Fast Fourier Transforms and power spectral densities. A signal, as a means to assess catalyst performance such as a signal based on sensing oxygen concentration in motor vehicle exhaust in accordance with the present invention is in the time domain and has multiple components at different frequencies. The use of Fast Fourier Transforms isolates the various spectral density which arise from different frequency components of the complex time domain signal. The analysis has been found to be substantially independent of operating conditions. The power spectral density has found to be a precise indication of oxygen storage and release of the catalyst and catalyst performance. The catalyst performance can be signaled to the vehicle operator for on board diagnostics (OBD) of the catalyst.

Abstract: Oxidation catalyst compositions for treating diesel exhaust include ceria and, optionally, alumina, each having a surface area of at least about 10 m2/g, and a zeolite, e.g., Beta zeolite. Optionally, platinum may be included in the catalytic material, preferably in amounts which are sufficient to promote some gas-phase oxidation of carbon monoxide (“CO”) and hydrocarbons (“HC”) but which are limited to preclude excessive oxidation of SO2 to SO3. Alternatively, palladium in any desired amount may be included in the catalytic material. The zeolite is optionally doped, e.g., ion-exchanged, with one or more of hydrogen, a platinum group metal or other catalytic metals. The catalyst compositions may be used in a method to treat diesel engine exhaust by contacting the hot exhaust with the catalyst composition to promote the oxidation of gas-phase CO and HC and of the volatile organic fraction component of particulates in the exhaust.

Abstract: Methods and apparatus for reducing the TPM level of a diesel engine exhaust stream by providing a suitable oxidation catalyst into the exhaust train. The oxidation catalyst may be incorporated into a thermal insulative coating on the inner surface of the exhaust train, particularly the exhaust manifold and exhaust pipes prior to the turbocharger. Alternatively, when the exhaust train includes a turbocharger, the catalyst can be in a separate monolithic unit between the engine and the turbocharger. The system may also include an improved diesel oxidation catalyst unit having a metal monolithic substrate. The oxidation catalyst can also be incorporated into a thermal insulative coating inside the cylinders, particularly on non-rubbing surfaces such as The invention also includes the use of a protective mullite top coat on the thermal coating. A further embodiment is the use of a stainless steel bond coat to bind the thermal coating to a metallic substrate, particularly an aluminum substrate.

Abstract: A stable, close-coupled catalyst, an article comprising the close-coupled catalyst and a related method of operation. The close-coupled catalyst comprises a catalyst support and a palladium catalytic component. Preferably and optionally, there are stabilizers including alkaline metal oxide, and rare earth metal components selected from the neodymium and lanthanum components. The close-coupled catalyst composition includes substantially no additional oxygen storage component such as praseodymium or cerium compounds. There is preferably a catalyst such as a three-way catalyst downstream of the close-coupled catalyst. The downstream catalyst preferably includes an oxygen storage component such as cerium oxide or praseodymium oxide.