Engelhard Minerals & Chemicals Corporation

Engelhard Corporation

Carl D Keith

John J Mooney

Charles E Thompson

William A Mannion

Robert E Kenson

Daniel L Bair

Saul G Hindin

Jack J Early

Thomas Shimrock

William R Larsen

Kurt W Cornely

This invention provides polyfunctional catalysts comprising a composite of platinum and one or more of rhodium, ruthenium and iridium, a substantially larger quantity of one or more base metal oxides in which the metal is selected from the group consisting of metals having an atomic number from 25 to 28 and rhenium, and an alumina support, which composite is made and then deposited on a suitable carrier. In a preferred embodiment, the catalysts contain 1-20 weight percent of said base metal oxide, typically nickel oxide; 0.05-0.5 weight percent platinum; and 0.002-0.3 weight percent rhodium, and an alumina support deposited on a monolith or other carrier. The improved catalysts are especially applicable for purifying exhaust gases from combustion processes, and in particular those from internal combustion engines. These polyfunctional catalysts have in a single formulation, the ability to accomplish four objectives--to oxidize carbon monoxide and unburned hydrocarbons while reducing nitrogen oxides, thereby converting those contaminants found in the exhaust of internal combustion engines into carbon dioxide, water and elemental nitrogen, but without producing significant amounts of hydrogen sulfide, sulfur trioxide or sulfuric acid. Such chemical conversions take place over the catalyst when the ratio of air to fuel supplied to the catalyst is controlled to nearly stoichiometric conditions, thereby maintaining the exhaust feed gases within a narrow compositional range, sometimes called a 'window', in which the catalyst can substantially convert the contaminants.

Polyfunctional catalysts and method of use

Macrosized catalysts suitable for promoting chemical reactions, especially to reduce pollutants in waste gas streams such as automobile exhaust, are described. The catalysts have one or more metal components, especially a platinum group metal component, as a catalytic promoter combined with a high surface area, refractory oxide support. Alumina is added to the macrosize catalyst to provide protection against poisoning by extraneous materials such as lead, zinc, other metals, sulfur or phosphorus with which the catalysts may come in contact during use. These catalysts may have a relatively catalytically-inactive carrier, especially a monolithic carrier which may be of the honeycomb type.

Catalyst for reducing pollutants in waste gas streams and process for

An air-to-fuel ratio control mechanism in an internal combustion engine operates in partial response to the output of a control circuit, which circuit in turn is responsive to the output of an oxygen sensor mounted in the exhaust of the engine. The control circuit biases the control mechanism toward a predetermined desired air-to-fuel ratio, normally at or near stoichiometric. When the sensor output deviates above a first predetermined value or below a second predetermined value for longer than a predetermined time period, a comparator circuit provides a disabling signal which disconnects the control circuit from the air-to-fuel ratio control mechanism. At the same time, the disabling signal connects a predetermined signal to the air-to-fuel ratio control mechanism. This predetermined signal simulates a nominal control circuit output to maintain the air-to-fuel ratio close to stoichiometric or some other preferred setting such as a air/fuel ratio which is lean. An indicator is turned on by the disabling signal to alert the operator to possible malfunction.

Oxygen sensor control system

Macrosized catalysts suitable for promoting chemical reactions, especially to reduce pollutants in waste gas streams such as automobile exhaust, are described. The catalysts have one or more metal components, especially a platinum group metal component, as a catalytic promoter combined with a high surface area, refractory oxide support on a relatively catalytically-inactive carrier, especially a monolithic carrier which may be of the honeycomb type. An aqueous solution of an alumina precursor is added to the macrosize catalyst to provide protection against poisoning by extraneous materials such as lead, zinc, other metals, sulfur or phosphorus with which the catalysts may come in contact during use.

Catalyst and process of its preparation

Catalysts are disclosed which have good activity and life when used to promote the conversion of hydrocarbons, carbon monoxide and nitrogen oxides contained in small concentrations in gaseous streams, to obtain the less noxious materials, carbon dioxide, water and nitrogen. The catalysts contain a catalytically-promoting, platinum group metal component, a catalytically-promoting, base metal component added as a solid material, and an alumina support component, deposited on a macrosize carrier. The base metal component contains a metal selected from the group consisting of metals having an atomic number from 25 to 28 and rhenium. The base metal and alumina components are preferably composited before deposition on the macrosize carrier, and the composite may also contain the platinum group metal component before such deposition. The catalytically-promoting metal components and alumina support can be comminuted as a slurry, and the liquid medium of the slurry is preferably acidic. The macrosize carrier, bearing the catalytic components may be dried and, if desired, calcined. The catalysts contain platinum or palladium, especially platinum, and preferably, one or more of rhodium, ruthenium and iridium, especially rhodium, in order to promote adequately the simultaneous conversion of hydrocarbons, carbon monoxide and nitrogen oxides to less noxious materials.

Catalyst compositions and the method of manufacturing them

Catalysts are disclosed which have good activity and life when used to promote the conversion of hydrocarbons, carbon monoxide and nitrogen oxides contained in small concentrations in gaseous streams, to obtain the less noxious materials, carbon dioxide, water and nitrogen. The catalysts contain a catalytically promoting, platinum group metal component, a catalytically promoting, base metal component and an alumina support component, deposited on a high surface area, particulate, macrosize carrier. The base metal component contains a metal selected from the group consisting of metals having an atomic number from 25 to 28 and rhenium.

This invention provides polyfunctional catalysts comprising a composite of platinum and one or more of rhodium, ruthenium and iridium, a substantially larger quantity of one or more base metal oxides in which the metal is selected from the group consisting of metals having an atomic number from 25 to 28 and rhenium, and an alumina support, which composite is made and then deposited on a suitable carrier. In a preferred embodiment, the catalysts contain 1-20 weight percent of said base metal oxide, typically nickel oxide; 0.05-0.5 weight percent platinum; and 0.002-0.3 weight percent rhodium, and an alumina support deposited on a monolith or other carrier. The improved catalysts are especially applicable for purifying exhaust gases from combustion processes, and in particular those from internal combustion engines. These polyfunctional catalysts have in a single formulation, the ability to accomplish four objectives - to oxidize carbon monoxide and unburned hydrocarbons while reducing nitrogen oxides, thereby converting those contaminants found in the exhaust of internal combustion engines into carbon dioxide, water and elemental nitrogen, but without producing significant amounts of hydrogen sulfide, sulfur trioxide or sulfuric acid. Such chemical conversions take place over the catalyst when the ratio of air to fuel supplied to the catalyst is controlled to nearly stoichiometric conditions, thereby maintaining the exhaust feed gases within a narrow compositional range, sometimes called a 'window,' in which the catalyst can substantially convert the contaminants.

Polyfunctional catalysts

There is disclosed a process for isomerizing alkylated benzenes having from 3-10 carbon atoms and methyl or ethyl alkyl substituents. The reaction is conducted in the presence of molecular hydrogen and a catalyst having a platinum group metal, especially platinum, and rhenium promoters on a porous, solid oxide, acidic support. The support can be a mixture of a low acidic material such as alumina, and a higher acidic material such as silica-alumina or crystalline aluminosilicate. The catalyst promoters are preferably supported on the low acidity base component.

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Summit, NJ, United States of America

Carl D Keith