Abstract: Improved catalysts for conversion of exhaust from internal combustion engines are produced by providing a unique, promoted support consisting of a mixed-metal-oxide promoter substantially uniformly dispersed as homogeneous crystallites of less than about 100 Å on a high surface area refractory oxide support substrate. The promoted support is made by a process that involves dissolving a combination of a primary metal oxide precursor with the oxide precursor of at least one additional metal and a compatible organic depositing agent, slowly heating to transform the depositing agent into a gel-like matrix coating the substrate in which the mixed-metal-oxide precursor compounds are uniformly distributed and thereafter calcining to burn off the organic matrix and form the appropriate oxide morphology.

Abstract: The present invention relates to catalyst support comprising an inorganic oxide, preferably alumina, and zeolite in the proton form and having a high Si/Al ratio, wherein the zeolite is selected from those protonated zeolites that would exhibit a high Na/Al mole ratio if treated with a solution of sodium nitrate until all sites that will accept a sodium ion have done so. This invention also relates to catalyst that is made from such support, to a method of treating exhaust gas from “lean-burn” engines using catalyst of this invention, and to a method for determining if a zeolite is a suitable support component.

Abstract: A method of reducing the amounts of nitrogen oxides and hydrocarbons in the exhaust gas from a small, gasoline-fueled utility engine operating fuel-rich, while not reducing the amount of carbon monoxide in said exhaust gas, comprising treatment of said exhaust gas by a catalyst consisting essentially of rhodium supported on an alumina-based washcoat applied to a substrate.

Abstract: The invention provides a catalyst which can convert methane, carbon monoxide, and nitrogen oxides in lean, stoichiometric, and rich air/fuel environments. Support (A) of the catalyst comprises an alumina support impregnated with Pd providing lean methane conversions and support (B) of the catalyst comprises ceria/lanthana/alumina impregnated with Pd providing stoichiometric methane conversion. Rhodium may be substituted for all or part of the Pd on an alumina support.

Abstract: A catalytic converter for treating exhaust gas from an internal combustion engine containing a catalyst characterized by having platinum or a platinum alloy dispersed predominantly on the exterior surface of molecular sieve crystals. Also provided is a catalyst for such a converter and processes for manufacture of such catalyst. In addition, methods for treating exhaust gas from an internal combustion engine to reduce the amounts of hydrocarbon, carbon monoxide and nitrogen oxides emitted to the atmosphere are included.

Abstract: Removal of carbon monoxide, hydrocarbons, and nitrogen oxides from the exhaust gas from lean-burn, diesel and other engines which produce exhaust gases containing excess oxygen is provided by a multi-component catalyst having at least two catalytic components, each capable of reducing nitrogen oxides within a range of exhaust gas temperatures that is different from the range of exhaust gas temperatures within which each other component is capable of reducing nitrogen oxides. Oxidation of the remaining reducing gases is also accomplished. One example of a two catalytic component catalyst of this invention has a first component of Au supported on alumina, which reduces nitrogen oxides at exhaust gas temperatures between about 600.degree. C. and 900.degree. C., and a second component of Pt supported on Y-zeolite, which reduces nitrogen oxides at exhaust gas temperatures below 600.degree. C.; an example of a three catalytic component catalyst of this invention has a first component of CoO supported on .gamma.

Abstract: A method of making a unique, promoted support for improved catalysts for conversion of exhaust from internal combustion engines, said support comprising a mixed-metal-oxide promoter containing at least Ce and Zr substantially uniformly dispersed as homogeneous crystallites of less than about 100 .ANG. on a high-surface-area refractory oxide support substrate, comprising dissolving a combination of Ce- and Zr-oxide precursors, and optionally another metal oxide precursor, and a compatible organic depositing agent, slowly heating to transform the depositing agent into a gel-like matrix coating the substrate in which the mixed-metal-oxide precursor compounds are uniformly distributed and thereafter calcining to burn off the organic matrix and form the appropriate oxide morphology.

Abstract: The present invention discloses a method of making materials and coatings formed from multiple component compositions characterized by improved uniformity, improved dispersion and/or improved homogeneity on the atomic, nanometer, or sub micron scale. These compositions are prepared by forming a mixture of component precursors in the presence of at least one suitable organic reagent and a solvent. Suitable reagents include those in which the sum of the hydroxy and carboxy groups contained in their molecular structure is at least two, which form a rigid, gel-like matrix upon suitable treatment and which decompose completely at high temperatures, leaving no residue. This method is useful for making compositions that are useful in the production of ceramics, supports, catalysts, modified supports, electronics, coatings, films, laminates, superconductors and similar products.

Abstract: An SO.sub.2 -tolerant catalyst for reducing NO.sub.x, in exhaust gas from internal combustion, wherein the exhaust gas contains unburnt hydrocarbons and oxygen comprising silver oxide dispersed on alumina characterized in that such catalyst is white in color.

Abstract: Removal of carbon monoxide, hydrocarbons, and nitrogen oxides from the exhaust gas from lean-burn, diesel and other engines which produce exhaust gases containing oxygen in substantial excess of stoichiometric is provided by catalysts containing platinum alloyed with cobalt, nickel, copper, rhodium, palladium, silver or gold. Alloying is accomplished by thermal treatment or by colloidal methods. The catalysts are capable of reducing nitrogen oxides (NO.sub.x) within a predetermined range of engine operating temperatures.

Abstract: Methods of making substantially phase-pure and thermally stable crystalline alumina compositions stabilized with an oxide of silicon, germanium, phosphorus, arsenic or a mixture thereof. Also provided are crystalline alumina compositions and catalyst supports made using these methods.

Abstract: A process for the removal of carbon monoxide, hydrocarbons, and nitrogen oxides in an oxidizing exhaust gas comprising contacting the exhaust gas with a catalyst comprising a crystalline zeolite having the following characteristics:a) a Si/Al atomic ratio between 5 and 100;b) a pore size in the range of from about 0.5 to about 1.3 nm;c) essentially no octahedral aluminum detectable by .sub.27 Al NMR spectroscopy;d) a sodium ion exchange capacity, with regard to total aluminum content, of greater than 75%;e) a copper content in the range of from about 0.5 wt. % to about 12 wt. %; andf) a silver content in the range of from about 0.25 wt. % to about 20 wt. %.

Abstract: A catalyst for the removal of carbon monoxide, hydrocarbons and nitrogen oxides in an exhaust gas made by a process comprising:a) preparing a suspension comprising a liquid, a zeolite, a weak base, and salts of copper and silver,said zeolite being crystalline and having a Si/Al atomic ratio between about 5 and about 100, a pore size between about 0.5 nm and about 1.3 nm, essentially no octahedral aluminum detectable by .sup.27 Al NMR spectroscopy and a sodium ion exchange capacity, with regard to total aluminum content, greater than 75%, and wherein said suspension contains sufficient amounts of said copper and silver salts to result in a copper content in said catalyst, when finished, between about 0.5 wt. % and about 12 wt. % and a silver content between about 0.25 wt. % and about 20 wt.

Abstract: A catalytic converter for treating exhaust gas from an internal combustion engine containing a catalyst characterized by having platinum or a platinum alloy dispersed predominately on the exterior surface of molecular sieve crystals. Also provided is a catalyst for such a converter and processes for manufacture of such catalyst. In addition, a process for treating exhaust gas from an internal combustion engine to reduce the amounts of hydrocarbon, carbon monoxide and nitrogen oxides emitted to the atmosphere is included.

Abstract: New thermally- and hydrothermally-stable .delta.-alumina compositions stabilized with an oxide of silicon, germanium, phosphorus, arsenic or a mixture thereof and methods of preparation of same are provided. Also provided are catalyst supports and catalysts made using these stabilized .delta.-alumina compositions, methods for making same, and methods for treating the exhaust gas from an internal combustion engine using such catalysts.

Abstract: A high activity catalyst and the method of using it to effectively convert the hydrocarbon, soluble oil fraction and carbon monoxide in a diesel exhaust stream while minimizing the oxidation of SO.sub.2 is disclosed. The catalyst comprises at least one platinum group metal dispersed on a two-component support comprising in major amount one or more zeolites and in minor amount an inorganic oxide selected from the group consisting of alumina, titania and mixtures thereof.

Abstract: The invention provides a catalyst which can convert methane, carbon monoxide, and nitrogen oxides in lean, stoichiometric, and rich air/fuel environments. Support (A) of the catalyst comprises an alumina support impregnated with Pd providing lean methane conversions and support (B) of the catalyst comprises ceria/lanthana/alumina impregnated with Pd providing stoichiometric methane conversion. Rhodium may be substituted for all or part of the Pd on an alumina support.

Abstract: A palladium three-way catalyst is supported on a unique ceria-lanthana-alumina support where the alumina content is lower than previously believed necessary to maintain catalyst activity. Preferably the ceria and lanthana constitute the major proportion of the support.