Abstract: The invention relates to a process for the formation of a coating of metal oxides comprising at least one precious metal from Group VIII of the Periodic Table of the elements, optionally in combination with titanium and/or zirconium, on an electrically conductive substrate made of steel or of iron, which consists in applying a sole solution of acetylacetonate(s) of the said metal(s) dissolved in a (plurality of) solvent(s) which specifically dissolve(s) each metal acetylacetonate; and in then drying and calcining the coated substrate. The invention also relates to an activated cathode obtained from the electrically conductive substrate coated with metal oxides and to its use in the electrolysis of aqueous solutions of alkali metal chlorides.

Abstract: The invention relates to a process for the formation of a coating of metal oxides comprising at least one precious metal from Group VIII of the Periodic Table of the elements, optionally in combination with titanium and/or zirconium, on an electrically conductive substrate made of steel or of iron, which consists in applying a sole solution of acetylacetonate(s) of the said metal(s) dissolved in a (plurality of) solvent(s) which specifically dissolve(s) each metal acetylacetonate; and in then drying and calcining the coated substrate. The invention also relates to an activated cathode obtained from the electrically conductive substrate coated with metal oxides and to its use in the electrolysis of aqueous solutions of alkali metal chlorides.

Abstract: A cathode comprising an electrically conductive substrate made of titanium, nickel, tantalum, zirconium, niobium, iron or alloys thereof, coated with an intermediate layer of oxides of titanium and of a precious metal, and with an outer layer comprising metal oxides of titanium, zirconium and a precious metal, can be used for the electrolysis of solutions, in particular for the electrolysis of aqueous solutions of alkali metal chlorides.

Abstract: The invention relates to a specific cathode comprising a substrate made of an element chosen from the group formed by titanium, nickel, tantalum, zirconium, niobium and alloys thereof, the said substrate being coated with an interlayer of a mixed oxide based on titanium and on ruthenium and with an external layer of metal oxides comprising titanium, zirconium and ruthenium. The subject of the invention is also its manufacturing process and its applications in electrolysis.

Abstract: In order to prepare tetramethylammonium hydroxide by electrolysis of a tetramethylammonium salt in a cell with a cation-exchange membrane, the operation is carried out continuously under stationary conditions obtained, on the one hand, by the introduction, into the anode electrolysis loop, of a tetramethylammonium salt solution which is more concentrated than that present in the cell and by an input of water into the cathode loop and, on the other hand, by the withdrawal of a portion of each of the solutions circulating in the anode and cathode loops.

Abstract: The invention relates to a method for shutting down an electrolysis cell with a membrane and an oxygen-reducing cathode, which comprises, after the electrical power and oxygen supplies have been disconnected, in emptying the oxygen compartment and filling it with demineralized water having a pH≦7 and in keeping this water in the oxygen compartment throughout the shutdown period.

Abstract: The invention relates to a stabilized bimetal catalyst comprising an electrically conductive support and a metallic deposited coating consisting of a first metal M1 chosen from platinum and silver and a second metal M2, different from the first and chosen from the group consisting of platinum, silver, gold, ruthenium, iridium, rhodium and osmium. The invention also relates to a process for obtaining such a catalyst.

Abstract: Electrolysing an aqueous solution of sodium chloride by means of a cell comprising a cation-exchange membrane which divides the cell into an anode compartment and an cathode compartment in which the said cathode is placed directly against the cation-exchange membrane, the said cathode compartment being supplied with a humidified gas containing oxygen, characterized in that, in order to obtain a concentration by weight of sodium hydroxide between the cation-exchange membrane and the cathode of less than 38.8%, use is made of an aqueous solution of sodium chloride (anolyte) having a concentration by weight of sodium chloride of less than 200 g/l, and in that the water humidifying the gas containing oxygen is in the form of water vapour.