Abstract: A catalyst comprising at least one porous support, at least some platinum, and at least a second group VIII metal which is different from platinum and iridium, said catalyst having been prepared in accordance with a process comprising a) impregnation of the support with at least one solution containing a platinum precursor, b) activation in a neutral or oxidizing atmosphere, at a temperature of between 120 and 800° C., c) activation in a reducing medium, at a temperature of between 0 and 800° C., d1) impregnation with an aqueous solution and d2) treatment with at least one hydrogen donor compound, at a temperature of less than 200° C., e) the impregnation of the support, which has already been impregnated with the platinum, with at least one solution containing a precursor of said second group VIII metal, and f) activation in a neutral, reducing, or oxidizing atmosphere, at a temperature of between 100 and 800° C.

Abstract: A description is given of a catalyst comprising at least one porous support, at least some platinum, and at least a second group VIII metal which is different from platinum and iridium, said catalyst having been prepared in accordance with a process comprising a) impregnation of the support with at least one solution containing a platinum precursor, b) activation in a neutral or oxidising atmosphere, at a temperature of between 120 and 800° C., c) activation in a reducing medium, at a temperature of between 0 and 800° C., d1) impregnation with an aqueous solution and d2) treatment with at least one hydrogen donor compound, at a temperature of less than 200° C., e) the impregnation of the support, which has already been impregnated with the platinum, with at least one solution containing a precursor of said second group VIII metal, and f) activation in a neutral, reducing, or oxidising atmosphere, at a temperature of between 100 and 800° C.

Abstract: This invention concerns conductive materials based on an encapsulated conductive polymer. Encapsulation in a shell of polymer stabilizes the conductivity of these materials, which can be encapsulated in a shell of film-generating polymer, to give the material formed very good mechanical properties, unlike conductive polymers which existed in the prior art, which, if not encapsulated, form brittle materials that are less stable in time.

Abstract: A material based on a conductive polymer consisting of particles of conductive polymer (P.sub.0), each particle being wrapped in a shell of water-insoluble, cross-linked polymer (P.sub.1).