Ford Motor Company Limited

Ford Global Technolgoies, LLC

E.i. Dupont De Nemours and Company

Mohinder S Chattha

Robert J Kudla

Somasundaram Subramanian

William L Watkins

Ares N Theodore

Haren S Gandhi

Walter O Siegl

William Lewis Henderson Watkins

Henk Van Oene

Jun (John) Li

Clifford N Montreuil

Amy Berris

Chaitanya Kumar Narula

Joseph C Cassatta

Clifford Norman Montreuil

Milton D Johnson

Tjenga E Hoost

Joseph W Holubka

Ray A Dickie

Elaine C Beckwith

Harendra Sakarlal Gandhi

Robert J Kudia

T E Hoost

Jun Li

Elaine C Siwiec Beckwith

Diane L Guttridge

Henk vanOene

An automobile exhaust system includes a catalytic converter and a modified NOx trap wit improved sulfur tolerance. Sulfur oxide has a deleterious effect on the performance of nitrogen oxide traps. In the modified NOx trap, a sulfur oxide trap is integrated with a nitrogen oxide trap by coating the catalyst contained within a nitrogen oxide trap with a mixed oxide layer of calcium oxide and magnesium oxide. The NOx trap is regenerated by heating at elevated temperature for a short time period.

Vehicle sulfur oxide trap and related method

An automobile exhaust system includes a catalytic converter, a NOx trap, and a sulfur oxide trap. The sulfur oxide trap improves the efficiency of the NOx trap. Sulfur oxide has a deleterious effect on the performance of nitrogen oxide traps. The sulfur oxide trap comprises a monolithic substrate which is over-coated with an aluminum oxide layer and a mixed oxide layer of calcium oxide and magnesium oxide. In a variation, a sulfur oxide trap is integrated with a nitrogen oxide trap by coating the catalyst contained within a nitrogen oxide trap with a mixed oxide layer of calcium oxide and magnesium oxide. In each embodiment, the sulfur oxide trap can be regenerated by heating at elevated temperature for a short time period.

An integrated lean NO trap. The integrated lean NO trap includes a lean NO trap containing a composite metal oxide mixture consisting essentially of about 80-100 wt % stoichiometric spinel MgAl O and between about 0-20 wt % of CeO or CeO &mdash;ZrO . A method for removing NO and SO impurities from exhaust gases using the integrated lean NO trap is also described.

Sulfur tolerant lean NOx trap

The invention is a method of treating exhaust gases generated by an internal combustion engine using a NO trap in the exhaust flow system. The method comprises locating a nitrogen oxide trap in the exhaust gas passage and cycling the air/fuel ratio of the exhaust gases entering the trap between lean and rich, such that the trap absorbs nitrogen oxides during the lean cycle and desorbs the nitrogen oxides when the concentration of the oxygen in the exhaust flow is lowered as during a rich cycle. The trap comprises: (a) a porous support material comprising mostly &ggr;-alumina; (b) a sulfur-suppressing metal selected from the group consisting of cesium, zinc and a combination of cesium and zinc; (c) a precious metal; and (d) a NO sorption metal such as barium, the metals being deposited in the support material, the amount of the metals being individually dependent on the weight of the support material. The desorbed nitrogen oxides may be converted over the precious metal to N by reductants like hydrogen, hydrocarbon and carbon monoxide present in the exhaust gas.

Modified platinum NOx trap for automotive emission reduction

The invention is a method for treating diesel exhaust gases, i.e., in an oxidizing atmosphere, with a catalyst which has a broadened operating temperature window at higher temperatures. It is a mixture of particles comprising platinum/alumina and a bi-metal oxide of manganese and zirconium.

Diesel catalyst made from a mixture of particles: platinum on alumina and manganese-zirconium oxide

The invention is a selective reduction catalyst useful for converting exhaust gases generated by a diesel engine where the atmosphere is oxidizing. The catalyst comprises 5-40 wt. % silica of a silica/alumina sol-gel produced support carrying 0.25-4.0 wt. % platinum.

Method for treating diesel engine exhaust gas

The invention is a method of treating exhaust gases generated by an internal combustion engine using a NOx trap in the exhaust gas system. The method comprises locating a nitrogen oxide trap in the exhaust gas passage and cycling the air/fuel ratio of the exhaust gases entering the trap between lean and rich, such that the trap absorbs nitrogen oxides during the lean cycle and desorbs the nitrogen oxides when the concentration of the oxygen in the exhaust gas is lowered as during a rich cycle. The trap comprises: (a) a tri-metal oxides made of aluminum-manganese-zirconium and (b) at least 0.1 wt. % platinum, the wt. % being based on the weight of said tri-metal oxide material. The desorbed nitrogen oxides may be converted over the precious metal to N.sub.2 and O.sub.2 by reductants like hydrocarbons present in the exhaust gas. The invention is also the catalyst trap material.

NOx trap catalyst for lean burn engines

A method is provided for treating diesel engine exhaust gas with a catalyst containing a physical mixture of particles. The catalyst contains a physical mixture of particles of (i) a bi-metal oxide of manganese and zirconium and (ii) a precious metal, such as platinum, supported on an alumina, such as gamma alumina.

Treating diesel exhaust with a catalytic particulate mixture

The invention is a method of treating exhaust gases generated by an internal combustion engine using a NOx trap in the exhaust gas system. The method comprises locating an essentially alkaline earth-free nitrogen oxide trap in the exhaust gas passage and cycling the air/fuel ratio of the exhaust gases entering the trap between lean and rich, such that the trap absorbs nitrogen oxides during the lean cycle and desorbs the nitrogen oxides when the concentration of the oxygen in the exhaust gas is lowered as during a rich cycle. The trap comprises: (a) a porous support material comprising mostly .gamma.-alumina and (b) metals consisting essentially of 0.1 to 2 wt. % tungsten oxide and precious metal comprising 0.5 to 4 wt. % platinum deposited on the support, the amount of said metals being individually based on the weight of said support material. The desorbed nitrogen oxides may be converted over the precious metal to N.sub.2 and O.sub.2 by reductants like hydrocarbons present in the exhaust gas.

Tungsten-modified platinum NOx traps for automotive emission reduction

This invention is a sulfur-resistant, high surface area and temperature stabilized anatase crystal form of a mixed-oxide of titania and alumina comprising at least 40% molar amount titania. The mixed-oxide is made by co-hydrolysis of a mixture of the alkoxides of titanium and aluminum. The mixed oxide is useful as a catalyst support for treating exhaust gases generated by a diesel or gasoline internal combustion engine of automotive vehicles. The catalyst support may contain catalytic materials like precious metals.

High surface area, thermally stabilized titania automotive catalyst

The invention is a nitrogen oxide trap comprising a porous support of alumina; and loaded thereon materials consisting essentially of particular amounts of: (I) tungstophosphoric acid and (II) precious metal selected from platinum, palladium, rhodium and mixtures thereof. The trap is useful for trapping nitrogen oxides produced in the exhaust gas generated by an internal combustion gasoline engine during lean-burn operation of the engine. The trap releases the nitrogen oxides during decreased oxygen concentration in the exhaust gas. The desorbed NOx may be converted over the precious metal to N.sub.2 and O.sub.2 by reductants like hydrocarbons present in the exhaust gas.

Sulfur-resistant NO.sub.x traps containing tungstophosphoric acid and

This invention is a bimetallic catalyst comprising tungsten oxide and platinum in critical amounts on a mostly .gamma.-alumina support material. It is particularly optimal for use in lean-burn engine exhaust systems, including gasoline and diesel, where it efficiently reduces NOx in the exhaust gas.

Bimetallic tungsten/platinum catalysts for lean-burn emissions

The present invention broadly relates to a catalyst for promoting the oxidation-reduction reactions of the exhaust gases produced by an internal combustion engine wherein the catalyst comprises; tungsten oxide, a basic metal oxide, and a noble metal. More narrowly, the present invention relates to a catalyst for promoting oxidation-reduction reactions with the exhaust gases produced by internal combustion engine wherein the catalyst comprises; a composite oxide comprised of a refractory oxide, tungsten oxide in juxtaposed relation with the refractory oxide, and a basic metal oxide in juxtaposed relation with the tungsten oxide; and arrayed on the composite oxide a noble metal.

Composite catalysts for hydrocarbon oxidation

A catalyst system for attaining high conversions of NO, HC, and CO in a fuel-lean emission flow (i.e., containing SO.sub.2, H.sub.2 O, H.sub.2, and considerable excess oxygen), the system comprising: (a) a first stage reducing catalyst for treating the nitric oxide emissions, the catalyst containing highly acidic gamma alumina (i.e., with a pH.sub.pzc of less than 3); (b) means for injecting gaseous or liquid reductants into the emission stream prior to entering said first stage catalyst, said first stage catalyst temperature being selected to be in the range of 550.degree.-650.degree. C.; and (c) an oxidation catalyst effective for treating the effluent from the first stage catalyst. Another aspect of this invention is a method of treating the exhaust gas from a fuel-lean emission flow from a fossil-fueled internal combustion engine having a redox ratio of 0.02-0.09, the method comprising: (a) injecting a gaseous or liquid HC or oxygenated HC reductant into the emission stream at a location where the stream is within the temperature range of 550.degree.-650.degree. C.; (b) immediately exposing the injected stream to a first stage catalyst containing acidic gamma alumina with a Ph.sub.pzc of less than 3; and (c) exposing the effluent from the first stage catalyst to an oxidation catalyst that is effective in ensuring that the NO, HC, and CO in the emissions are each converted to at least 80%.

Catalyst system for converting emissions of a lean-burn engine

The invention is a method for treating exhaust gases generated by a diesel engine by providing a sulfur-tolerant lean-NOx catalyst in an exhaust gas passage of the engine and contacting the catalyst with the exhaust gases. The sulfur-tolerant lean-NOx catalyst comprises a support of titania aerogel; and loaded thereon, using impregnation techniques from a solution of their precursors, at least 0.25 weight percent precious metal selected from platinum, palladium, rhodium, or mixtures thereof. The method converts the hydrocarbons, carbon monoxide and nitrogen oxides into more desirable gases. In particular, the NOx is converted to N.sub.2 and O.sub.2 over the catalyst.

Growing community of inventors

Livonia, MI, United States of America

Mohinder S Chattha