1409 results about "Oxygen storage" patented technology

A catalyst for treating exhaust gas from an internal combustion engine includes a carrier body coated with an inner layer and an outer layer. The inner layer includes platinum deposited on a first support material and on a first oxygen storage component, and the outer layer includes platinum and rhodium deposited on a second support material and on a second oxygen storage component. The first and second support materials may be the same or different, and may be selected from the group of: silica, alumina, titania, zirconia, mixed oxides or mixtures thereof, and zirconia-rich zirconia / ceria mixed oxide. The first and second oxygen storage components may include ceria-rich ceria / zirconia mixed oxide compounds, optionally including praseodymia, yttria, neodymia, lanthana or mixtures thereof.

A catalyst for treating the exhaust gas from internal combustion engines is provided, wherein the catalyst contains two catalytically active layers supported on a support. The first catalytically active layer contains a platinum group metal in close contact with all of the constituents of the first catalytically active layer, wherein the constituents of the first catalytically active layer include particulate aluminum oxide; particulate oxygen storage material, such as cerium oxide, cerium / zirconium and zirconium / cerium mixed oxides, and alkaline earth metal oxides. The second catalytically active layer, which is in direct contact with the exhaust gas, contains particulate aluminum oxide and at least one particulate oxygen storage material, such as cerium oxide, cerium / zirconium and zirconium / cerium mixed oxides. Rhodium is supported on part of the aluminum oxides in the second catalytically active layer or on the particulate oxygen storage material in the second catalytically active layer. By providing the platinum group metal in close contact with all of the constituents of the first catalytically active layer, improved conversion efficiency of the impurities in the exhaust gas can be achieved.

A layered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides is disclosed. In one or more embodiments, the catalyst comprises three layers in conjunction with a carrier: a first layer deposited on the carrier and comprising palladium deposited on a refractory metal oxide and an oxygen storage component; a second layer deposited on the first layer and comprising rhodium deposited on a refractory metal oxide and an oxygen storage component; and a third layer deposited on the second layer and comprising palladium deposited on a refractory metal oxide.

A layered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides is disclosed. In one or more embodiments, the catalyst comprises three layers in conjunction with a carrier: a first layer deposited on the carrier and comprising palladium deposited on a refractory metal oxide and an oxygen storage component; a second layer deposited on the first layer and comprising rhodium deposited on a refractory metal oxide and an oxygen storage component; and a third layer deposited on the second layer and comprising palladium deposited on a refractory metal oxide.

Provided are an exhaust treatment catalyst and an exhaust article containing the catalyst. The catalyst comprises:(a) a carrier;(b) a first layer deposited on the carrier, said first layer comprising substantially only at least one refractive metal oxide;(c) a second layer deposited on the first layer, said second layer comprising substantially only at least one oxygen storage component and at least one binder therefor; and(d) a third layer deposited on the second layer, said third layer comprising at least one layer of one or more platinum group metal components supported on a refractory metal oxide support.Optionally, a fourth layer is deposited on the third layer wherein the fourth layer comprises one or more platinum group metal components supported on a refractory metal oxide support. As a further option, an overcoat layer may be deposited on the third or fourth layer wherein the overcoat layer comprises a catalyst poison sorbent. Also provided are methods for preparing the catalyst and methods for monitoring the exhaust storage capacity of an exhaust article containing the catalyst.

An air-fuel ratio control system for an internal combustion engine estimates an oxygen storage amount of a catalyst based on a record of an oxygen storage amount, and controls an air-fuel ratio based on the estimated oxygen storage amount. The catalyst is divided into multiple sections in a flow direction of an exhaust gas, the oxygen storage amount in a specified section is estimated according to a behavior of an exhaust gas on upstream and downstream sides of the respective specified sections, and the air-fuel ratio is controlled based on the estimated oxygen storage amount in the specified section.

Provided is a base metal undercoat containing catalyst and an exhaust article containing the catalyst. The catalyst contains a base metal undercoat with an oxygen storage component, and at least one catalytic layer. Also provided are methods for preparing the catalyst and methods for monitoring the oxygen storage capacity of an exhaust article containing the catalyst.

An upstream side catalyst and a downstream side catalyst are disposed in an exhaust passage. A first oxygen sensor is disposed between these two catalysts and a second oxygen sensor is disposed downstream of the downstream side catalyst. The air-fuel ratio is forcibly oscillated and the oxygen storage capacity of the upstream side catalyst is detected. Deterioration of the upstream side catalyst is then detected based on whether this oxygen storage capacity is larger than a predetermined value. The forced oscillation of the air-fuel ratio is performed only when the oxygen storage state of the downstream side catalyst is appropriate.

A Solid Oxide Regenerative Fuel Cell (SORFC) or a Solid Oxide Fuel Cell (SOFC) is incorporated into an electrically powered airplane to provide either regenerative or primary electrical energy. The SORFC, the SOFC, or any other suitable fuel cell within an airplane may also be used to heat payload or equipment within the airplane. The SORFC is not only capable of generating electrical energy from fuel and a suitable oxidizer, but can also generate fuel through electrolysis of oxidized fuel. Thus, the SORFC system powering an airplane can obtain oxygen oxidant reactant from the air and avoid the complexity, weight, volume, and cost associated with oxygen storage.

A layered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides is disclosed. In one or more embodiments, the catalyst comprises three layers in conjunction with a carrier: a first layer deposited on the carrier and comprising palladium deposited on a refractory metal oxide and an oxygen storage component; a second layer deposited on the first layer and comprising rhodium deposited on a refractory metal oxide and an oxygen storage component; and a third layer deposited on the second layer and comprising palladium deposited on a refractory metal oxide.

Provided are an exhaust treatment catalyst and an exhaust article containing the catalyst. The catalyst comprises: (a) a carrier; (b) a first layer deposited on the carrier, said first layer comprising substantially only at least one refractive metal oxide; (c) a second layer deposited on the first layer, said second layer comprising substantially only at least one oxygen storage component and at least one binder therefor; and (d) a third layer deposited on the second layer, said third layer comprising at least one layer of one or more platinum group metal components supported on a refractory metal oxide support. Optionally, a fourth layer is deposited on the third layer wherein the fourth layer comprises one or more platinum group metal components supported on a refractory metal oxide support. As a further option, an overcoat layer may be deposited on the third or fourth layer wherein the overcoat layer comprises a catalyst poison sorbent. Also provided are methods for preparing the catalyst and methods for monitoring the exhaust storage capacity of an exhaust article containing the catalyst.

In an exhaust gas purification catalyst in which a catalytic coating containing plural kinds of aluminas and plural kinds of oxygen storage components each carrying a catalytic precious metal is coated on a honeycomb support, the catalytic coating is formed of an upper layer and a lower layer, palladium is carried on a first alumina and a Ce—Zr—La—Y-alumina compound having oxygen storage capacity in the lower layer, platinum is carried on a second alumina in the upper layer, and rhodium is carried on a third alumina and a Ce—Zr—Nd mixed oxide having oxygen storage capacity in the upper layer.

A high exhaust gas-purifying efficiency is achieved. An exhaust gas-purifying catalyst includes a substrate, an oxygen storage layer covering the substrate and including an oxygen storage material, and a catalytic layer covering the oxygen storage layer and including palladium, rhodium and a carrier supporting them, the catalytic layer having a precious metal concentration higher than that of the oxygen storage layer.

A layered exhaust treatment catalyst comprising: (a) a carrier such as cordierite; (b) a first layer deposited on the carrier comprising a palladium metal component, a platinum metal component and an oxygen storage component such as ceria supported on a refractory metal oxide such as gamma-alumina; and (c) a second layer deposited on the first layer comprising a rhodium metal component, a platinum metal component and an oxygen storage component such as ceria supported on a refractory metal oxide such as gamma-alumina. Preferably, the catalyst also includes a bottom layer interposed between the carrier and the first layer. The bottom layer comprises an oxygen storage component such as ceria supported on a refractory metal oxide such as gamma-alumina. The amount of the oxygen storage component of the catalyst may be “tuned”, i.e., adjusted, to meet the needs of a vehicle's on-board diagnostic (“OBD”) catalyst efficiency monitoring system, without adversely affecting the performance of the catalyst.

An air-fuel ratio control system for an internal combustion engine estimates an oxygen storage amount of a catalyst based on a record of an oxygen storage amount, and controls an air-fuel ratio based on the estimated oxygen storage amount. The catalyst is divided into multiple sections in a flow direction of an exhaust gas, the oxygen storage amount in a specified section is estimated according to a behavior of an exhaust gas on upstream and downstream sides of the respective specified sections, and the air-fuel ratio is controlled based on the estimated oxygen storage amount in the specified section.

Disclosed herein is a layered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides being separated in a front and rear portion is disclosed. Provided is a catalytic material of at least two front and two rear layers in conjunction with a substrate, where each of the layers includes a support, all layers comprise a platinum group metal component, and the rear bottom layer is substantially free of a ceria-containing oxygen storage component (OSC).

An electronic oxygen conserving device for controlling a flow of oxygen from an oxygen storage container to a user. When a conserve setting is selected, a flow of oxygen travels through an oxygen regulating valve that has an open state and a closed state. A temporary electrical charge or current is provided to the oxygen regulating valve during the initial inhalation of oxygen by an individual, opening the regulating valve opens to delivery oxygen to the user. The oxygen regulating valve remains open even after termination of the electric current. After a predetermined timed delivery dose or upon exhalation by the individual, a subsequent temporary electric charge or current is provided to oxygen regulating valve, closing the regulating valve closes to prevent delivery of oxygen to the user, thus conserving oxygen. The oxygen regulating valve remains closed even after termination of the subsequent electric current.

A layered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides is disclosed. In one or more embodiments, the catalyst comprises three layers in conjunction with a carrier: a first layer deposited on the carrier and comprising palladium deposited on a refractory metal oxide and an oxygen storage component; a second layer deposited on the first layer and comprising rhodium deposited on a refractory metal oxide and an oxygen storage component; and a third layer deposited on the second layer and comprising palladium deposited on a refractory metal oxide.

A catalyst and a method for selectively reducing nitrogen oxides (“NOx”) with ammonia are provided. The catalyst includes a first component comprising a zeolite or mixture of zeolites selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-18, ZSM-23, MCM-zeolites, mordenite, faujasite, ferrierite, zeolite beta, and mixtures thereof; a second component comprising at least one member selected from the group consisting of cerium, iron, copper, gallium, manganese, chromium, cobalt, molybdenum, tin, rhenium, tantalum, osmium, barium, boron, calcium, strontium, potassium, vanadium, nickel, tungsten, an actinide, mixtures of actinides, a lanthanide, mixtures of lanthanides, and mixtures thereof; optionally an oxygen storage material and optionally an inorganic oxide. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia at high temperatures. The catalyst has high hydrothermal stability. The catalyst has high activity for conversion of low levels of nitrogen oxides in exhaust streams. The catalyst and the method may have special application to selective reduction of nitrogen oxides in exhaust gas from gas turbines and gas engines, although the catalyst and the method have broad application to a wide range of gas streams that have excess oxygen and high temperatures. The temperature of exhaust gas from gas turbines and gas engines is high. Both the high temperature and the low levels of inlet NOx are challenging for selective catalytic reduction (SCR) catalysts.

Processes for preparing a composition comprising (i) an acidic metal oxide containing substantially no zeolite, (ii) an alkali metal, alkaline earth metal, and mixtures thereof, and (iii) an oxygen storage component are disclosed. Preferably, the process comprise forming a single slurry of components (i)-(iii), spray drying and calcining to obtain metal oxide particles comprising components (i)-(iii). Preferably, the slurry comprise a base peptized acidic metal oxide containing slurry wherein the component (ii) is provided in the slurry as a metal of the base. Compositions prepared are impregnated with a noble metal to provide compositions useful to reduce gas phase reduced nitrogen species and NOx in an effluent off gas of a fluid catalytic cracking regenerator.

A layered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides is disclosed. In one or more embodiments, the catalyst comprises three layers in conjunction with a carrier: a first layer deposited on the carrier and comprising palladium deposited on a refractory metal oxide and an oxygen storage component; a second layer deposited on the first layer and comprising rhodium deposited on a refractory metal oxide and an oxygen storage component; and a third layer deposited on the second layer and comprising palladium deposited on a refractory metal oxide.

A positive ignition engine is disclosed. The engine comprises an exhaust system comprising a filter for filtering particulate matter from the emitted exhaust gas. The filter comprises a porous substrate having inlet surfaces and outlet surfaces. The porous substrate is coated at least in part with a three-way catalyst washcoat comprising a platinum group metal and a plurality of solid particles. The plurality of solid particles comprises at least one base metal oxide and at least one oxygen storage component which is a mixed oxide or composite oxide comprising cerium. The mixed oxide or composite oxide comprising cerium and / or the at least one base metal oxide has a median particle size (D50) less than 1 μm. The platinum group metal platinum and rhodium; palladium and rhodium; platinum, palladium and rhodium; palladium only; or rhodium only. A process for treating exhaust gas using the filter is also disclosed.

A colorimetric reagent in the form of nanoparticles, composite nanoparticles, and nanoparticle coatings, including methods of use, methods of preparation, deposition, and assembly of related devices and specific applications. The colorimetric reagent comprises cerium oxide nanoparticles which are used in solution or immobilized on a solid support, either alone or in conjunction with oxidase enzymes, to form an active colorimetric component that reacts with an analyte to form a colored complex. The rate of color change and the intensity of the color are proportional to the amount of analyte present in the sample. Also described is the use of ceria and doped ceria nanoparticles as an oxygen storage / delivery vehicle for oxidase enzymes and applications in biocatalytic processes in anaerobic conditions of interest in biomedicine and bioanalysis. Further described are a variety of related applications of the disclosed technology including clinical diagnosis, in vivo implantable devices, food safety, and fermentation control.

Disclosed herein is a layered, three-way conversion catalyst having the capability of simultaneously catalyzing the oxidation of hydrocarbons and carbon monoxide and the reduction of nitrogen oxides being separated in a front and rear portion is disclosed. Provided is a catalytic material of at least two front and two rear layers in conjunction with a substrate, where each of the layers includes a support, all layers comprise a platinum group metal component, and the rear bottom layer is substantially free of a ceria-containing oxygen storage component (OSC).

An upstream side catalyst and a downstream side catalyst are disposed in an exhaust passage. A first oxygen sensor is disposed between these two catalysts and a second oxygen sensor is disposed downstream of the downstream side catalyst. The air-fuel ratio is forcibly oscillated and the oxygen storage capacity of the upstream side catalyst is detected. Deterioration of the upstream side catalyst is then detected based on whether this oxygen storage capacity is larger than a predetermined value. The forced oscillation of the air-fuel ratio is performed only when the oxygen storage state of the downstream side catalyst is appropriate.

A process for evaluating performance deterioration of a nitrogen oxide storage catalyst which has a nitrogen oxide storage function and an oxygen storage function and is operated with cyclic alternation of the air / fuel ratio in the exhaust gas from lean to rich. The nitrogen oxides are stored during the lean phase and the nitrogen oxides are desorbed and converted during the rich phase. To check the serviceability of the storage catalyst, the air / fuel ratio of the exhaust gas is switched from lean to rich and the rich phase is extended beyond the time required for complete desorption of the nitrogen oxides until at least the rich exhaust gas passes right through the catalyst and the time interval DELTAt1 produced between the first change-over until breakthrough of the rich exhaust gas and, after again switching from rich to lean running, the time interval DELTAt2 produced between the second change-over and passage of oxygen through the catalyst are measured and the time differences DELTAt1 and DELTAt2 are used for separate assessment of the oxygen storage function and the nitrogen oxide storage function of the catalyst.

The object of the invention is to provide an exhaust gas purifying catalyst having a high oxygen storage capacity without changing the usage amount of the oxygen storage component. According to the present invention, the exhaust gas purifying catalyst containing (a) a ceria-zirconia composite oxide containing ceria in a higher amount than zirconia, (b) a ceria-zirconia composite oxide containing zirconia in a higher amount than ceria, and (c) a ceria-zirconia composite oxide having a pyrochlore-type regular array structure is provided. The exhaust gas purifying catalyst of the present invention has a higher oxygen storage capacity than conventional catalysts and is effective in reducing the amount of NOx emission.

Disclosed herein is a three-way conversion (TWC) catalyst containing little or no rhodium for purifying exhaust gases of an internal combustion engine, having a multi-layers structure, including a lower layer including an alumina support and an oxygen storage material; an intermediate layer including alumina support impregnated only with palladium and a zirconia-rich oxygen storage material; and an upper layer including alumina support impregnated with platinum, minimum rhodium and platinum, or platinum-palladium and a ceria-rich oxygen storage material.