Abstract: A coating method comprising coating a metal having a metal oxide film with a refractory metal oxide using an aqueous slurry containing said refractory metal oxide, which is characterized in that said refractory metal oxide has an average particle diameter ranging from 0.7-3 microns.

Abstract: A monolithic catalyst for purification of exhaust gases is produced by a process which comprises coating a monolithic support with an aqueous slurry composition comprising a powder of active alumina, at least one compound of a platinum-group element selected from the group consisting of platinum, palladium and rhodium, and a powder of cerium hydroxide.

Abstract: A process for producing a high-temperature resistant honeycomb catalyst, which comprises admixing cerium, zirconium, at least one metal selected from the group consisting of iron and nickel, at least one metal selected from the group consisting of platinum, palladium and rhodium, and optionally at least one metal selected from the group consisting of neodymium, lanthanum and praseodymium, each in the form of an aqueous solution or dispersion of a soluble or easily water-dispersible compound of the metal, with active alumina, drying the mixture, calcining it, dispersing the resulting catalyst composition in an aqueous medium, and depositing the dispersion on a monolithic honeycomb carrier. The resulting catalyst is useful for simultaneous conversion of hydrocarbons, carbon monoxide and nitrogen oxides in an exhaust gas.

Abstract: A method for the manufacture of a honeycomb carrier of enhanced resistance to thermal shocks, which method comprises applying a coat of water-soluble high-molecular organic compound to the surface of a ceramic honeycomb carrier of monolithic construction and subsequently depositing a catalyst component on the resultant coated carrier.

Abstract: A method for the production of a platinum catalyst used for purification of exhaust and waste gases which comprises supporting platinum either alone or in combination of other noble metals on to a porous inorganic refractory support using an aqueous medium containing dinitrodiammineplatinum and, optionally, other noble metals or their compounds in the presence of a poly(oxyethylene) type nonionic surface active agent of an average molecular weight of at least 500 and subjecting the so treated support to activation by calcining in an oxidative atmosphere or by reducing in a reductive atmosphere.