Abstract: The disclosure herein relates to (a) a process for the preparation of catalysts which are highly active for oxidizing the carbon monoxide (CO) and hydrocarbon (HC) present in automobile exhaust gases, with minimum oxidation of the sulfur dioxide, by controlling the acidity of the support, or carrier, within certain critical ranges while a Group VIII noble metal component, or components, is composited with said support in forming the catalyst; (b) a process embodying the use of the so-formed catalysts in the treatment of automotive exhaust gases; and, (c) the catalyst compositions so-formed from supports the surface acidity of which is controlled. In the formation of the catalysts the total surface acidity of the support on which the metal, or metals, component is deposited is maintained between about 0.01 to about 0.10 micromoles pyridine/m.sup.2, and the surface area of the metal, or metals, component ranges up to about 50 m.sup.2 /g, preferably from about 1 m.sup.2 /g to about 35 m.sup.

Abstract: A high surface area perovskite catalyst comprises a perovskite containing at least one transition metal composited with a spinel coated metal oxide support. The catalyst is prepared by forming a surface spinel on a metal oxide and subsequently co-impregnating or co-depositing the appropriate perovskite precursor component on the spinel coated metal oxide, followed by calcination at a temperature of at least 540.degree. C. A preferred catalyst is LaCoO.sub.3 supported on a spinel covered alumina.

Abstract: A high surface area perovskite catalyst comprises a perovskite containing at least one transition metal composited with a spinel-coated metal oxide support. The catalyst is prepared by forming a surface spinel on a metal oxide and subsequently co-impregnating or co-depositing the appropriate perovskite precursor component on the spinel coated metal oxide, followed by calcination at a temperature of at least 540.degree. C. A preferred catalyst is LaCoO.sub.3 supported on a spinel-covered alumina.

Abstract: Hydrogen sulfide and its precursors can be selectively sorbed from gas streams containing the same by contacting the gas stream at elevated temperatures with a regenerable sorbent comprising a steam-treated support composited with a rare earth metal component. Presteaming the support lowers the amount of rare earth metal component needed to achieve a given activity level for hydrogen sulfide removal. Subsequent to sorption, the sorbent composite may be desorbed and regenerated by treatment with steam (desorption) and an oxidizing gas (regeneration). The sorbent capacity may be increased by the use of alkali or alkaline earth metal components as promoters. A preferred sorbent comprises lanthanum composited with presteamed alumina.

Abstract: Hydrogen sulfide and its precursors can be selectively sorbed from gas streams containing the same by contacting the gas stream at elevated temperatures with a regenerable sorbent comprising a steam-treated support composited with a rare earth metal component. Presteaming the support lowers the amount of rare earth metal component needed to achieve a given activity level for hydrogen sulfide removal. Subsequent to sorption, the sorbent composite may be desorbed and regenerated by treatment with steam (desorption) and an oxidizing gas (regeneration). The sorbent capacity may be increased by the use of alkali or alkaline earth metal components as promoters. A preferred sorbent comprises lanthanum composited with presteamed alumina.

Abstract: Hydrogen sulfide and its precursors can be selectively sorbed from gas streams containing same by contacting the gas stream at elevated temperatures with a regenerable sorbent comprising a supported or unsupported lanthanum or rare earth metal component. Subsequent to sorption, the sorbent may be desorbed and regenerated by treatment with steam (desorption) and an oxidizing gas (regeneration). The sorbent capacity may be increased by the use of alkali or alkaline earth metal components as promoters.