CATHODES A FAIBLE SURTENSION D'HYDROGENE, PRODEDE POUR LEUR PRODUCTION ET CELLULES ELECTROLYTIQUES LES COMPRENANT

LA PRESENTE INVENTION CONCERNE UNE CATHODE A FAIBLE SURTENSION D'HYDROGENE DESTINEE A ETRE UTILISEE DANS LES PROCESSUS ELECTRILYTIQUES, UN PROCEDE DE PRODUCTION DE CETTE CATHODE, ET LES CELLULES ELECTROLYTIQUES COMPORTANT DE TELLES CATHODES.LA CATHODE DE L'INVENTION EST CARACTERISEE EN CE QU'AU MOINS UNE PARTIE DE LA SURFACE DE CETTE CATHODE COMPREND UN CO-DEPOT D'UN PREMIER METAL CHOISI DANS LE GROUPE CONSTITUE PAR LE FER, LE COBALT, LE NICKEL, ET LEURS MELANGES, D'UN SECOND METAL OU OXYDE METALLIQUE LESSIVABLE, ET D'UN TROISIEME METAL CHOISI DANS LE GROUPE CONSTITUE PAR LE CADMIUM, LE MERCURE, LE PLOMB, L'ARGENT, LE THALLIUM, LE BISMUTH, LE CUIVRE, ET LEURS MELANGES.APPLICATION AUX CELLULES ELECTROLYTIQUES, NOTAMMENT DANS L'ELECTROLYSE DE SOLUTIONS AQUEUSES D'HALOGENURES DE METAUX ALCALINS. A cathode for use in electrolytic processes and a process for preparing such cathodes is described. The cathode has a cathodically active surface comprising a codeposit of a first metal selected from the group consisting of iron, cobalt, nickel, and mixtures thereof, a leachable second metal or metal oxide preferably selected from the group consisting of molybdenum, manganese, titanium, tungsten, vanadium, indium, chromium, zinc, their oxides, and combinations thereof, and a third metal selected from the group consisting of cadmium, mercury, lead, silver, thallium, bismuth, copper and mixtures thereof. Such cathodes are prepared by initially forming a codeposit of the three metals or metal oxides, and subsequently removing at least a portion of the second metal or metal oxide from the codeposit. The second metal or metal oxide component can be conveniently removed by leaching, utilizing an alkaline solution. A substantially reduced hydrogen cathode overvoltage is obtained when the present cathodes are utilized in an electrolytic cell.