Abstract: A process for applying a coating containing platinum and/or palladium to the surface of a porous catalyst carrier, the depth of penetration being controlled by preloading the carrier with a determined amount of aqueous solution containing ammonium chloride.

Abstract: A three-way catalyst is described for the purification of automobile exhaust gases formed of an active substance of platinum and rhodium and possibly base metal(s) at a certain weight ratio between the two noble metals and at a certain atomic ratio between the noble and the base metal, which are precipitated onto active aluminum oxide containing certain quantities of CeO.sub.2, ZrO.sub.2 and Fe.sub.2 O.sub.3, and whereby the catalyst is obtained by impregnating active aluminum oxide, possibly stabilized with alkaline earth metal, with a solution of cerium, zirconium and iron salt which is thereupon calcined in air at 500.degree.-700.degree. C. and then treated after application of an impregnation of salts of the active substance components in a gas current containing hydrogen at temperatures below 650.degree. C.

Abstract: An improved process for applying a coating or film of at least one catalytically active element to the external surface of a porous catalyst carrier having a large surface area by contacting said catalyst carrier with a solution of said at least one catalytically active element, wherein the improvement comprises:(1). Contacting said catalyst carrier with an organic liquid, wherein the saturation of said catalyst carrier is not exceeded;(2). Adding a solution of said at least one catalytically active element to said catalyst carrier; and(3). Heating said catalyst carrier to remove liquid therefrom.

Abstract: A catalyst is described capable of inducing reduction in nitrogen oxide pollutants of exhaust gases from internal combustion engines and industrial plants. The catalyst composition is formed from a mixture of catalytically active aluminum oxides and a mixture of at least two metal oxides, one which is chromium oxide and the other is an oxide of an element of the First Transition Series, impregnated with about 1% by weight of an impregnant comprising a catalytically active noble metal compound. An optional constituent of the catalyst compositions includes 0.5-10% by weight of beryllium, magnesium, calcium, strontium or barium in the mixed oxide composition.

Abstract: An improvement in producing an adherent metal oxide coating on a solid body comprises incorporating a nitrogen-containing polymer in a dispersion of the metal oxide into which the body is dipped. The pH of the dispersion is controlled in order to stabilize the dispersion. The body can then be dried. The invention is especially useful for applying a metal oxide coating to a ceramic material employed as a catalyst carrier for automotive exhaust gas purification.

Abstract: A carrier catalyst comprises as the catalytically active component an intermetallic system of at least three metals, wherein at least one of said three metals is selected from the group consisting of (a) ruthenium, rhodium, palladium and platinum, and wherein at least one of said three metals is a base metal selected from the group consisting of (b) aluminum, titanium, chromium, manganese, cobalt and nickel, and further wherein said group (a) metals and said group (b) metals are in an atomic ratio of about 1:4 to 1:1, provided that, when said system contains platinum, rhodium and at least one of said base metals, the atomic ratio is 1:4 to 1:2.4. The catalyst can also contain aluminum.

Abstract: A process for preparing an oxidic, carrier catalyst comprising at least one heavy metal compound as active component, said process comprising providing a carrier comprising a temperature resistant material with a catalytically active coating by intensively mixing said carrier with a binding agent, and at least one pulverulent, oxidic heavy metal compound or with a pulverulent mass containing at least one of said oxidic heavy metal compounds or at least one hydroxyl group-containing precursor of said heavy metal compounds, and subsequently heating the resulting mass to remove said binding agent. The catalyst and the process of using the catalyst in the purification of exhaust gases are provided.