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: 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: 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.