Abstract: The invention describes an electrochemical cell for the electrolysis of an aqueous solution of hydrogen chloride, comprising at least an anode half-cell with an anode, a cathode half-cell with a gas diffusion electrode as cathode and an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, the membrane consisting of at least a perfluorosulfonic acid polymer, wherein the gas diffusion electrode and the ion exchange membrane are adjacent to each other, characterised in that the gas diffusion electrode and the ion exchange membrane, under a pressure of 250 g/cm2 and at a temperature of 60° C., have a contact area of at least 50%, with respect to the geometric area.

Abstract: Electrode at least comprising an electroconductive support of a titanium-palladium alloy, titanium, tantalum or compounds or alloys of titanium or of tantalum, an electrochemically active coating and an interlayer between the support and the electrochemically active coating, wherein the interlayer consists of titanium carbide and/or titanium boride and is applied to the support by flame or plasma spraying. Process for producing these electrodes and their use in an electrochemical cell for producing chlorine or chromic acid.

Abstract: The present invention discloses a process for the production of a gas diffusion electrode, in particular for the electrolysis of an aqueous solution of hydrogen chloride, in a first step a) a dispersion of a catalyst containing a noble metal and of a proton-conducting ionomer in an organic solvent being sprayed onto an electrically conductive support optionally provided with a coating material containing an acetylene black/polytetrafluoroethylene mixture and, in a second step b), the organic solvent being removed.

Abstract: The invention describes an electrochemical cell for the electrolysis of an aqueous solution of hydrogen chloride, comprising at least an anode half-cell with an anode, a cathode half-cell with a gas diffusion electrode as cathode and an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, the membrane consisting of at least a perfluorosulfonic acid polymer, wherein the gas diffusion electrode and the ion exchange membrane are adjacent to each other, characterised in that the gas diffusion electrode and the ion exchange membrane, under a pressure of 250 g/cm2 and at a temperature of 60° C., have a contact area of at least 50%, with respect to the geometric area.

Abstract: The invention relates to a process for the electrochemical preparation of chlorine from aqueous solutions of hydrogen chloride in an electrolysis cell, comprising an anode chamber and a cathode chamber, the anode chamber being separated from the cathode chamber by a cation exchange membrane, the anode chamber containing an anode and the cathode chamber a gas diffusion cathode, and the aqueous solution of hydrogen chloride being passed into the anode chamber and an oxygen-containing gas into the cathode chamber, and the oxygen pressure in the cathode chamber being at least about 1.05 bar.

Abstract: The present invention discloses a process for the production of a gas diffusion electrode, in particular for the electrolysis of an aqueous solution of hydrogen chloride, in a first step a) a dispersion of a catalyst containing a noble metal and of a proton-conducting ionomer in an organic solvent being sprayed onto an electrically conductive support optionally provided with a coating material containing an acetylene black/polytetrafluoroethylene mixture and, in a second step b), the organic solvent being removed.

Abstract: Electrode at least comprising an electroconductive support of a titanium-palladium alloy, titanium, tantalum or compounds or alloys of titanium or of tantalum, an electrochemically active coating and an interlayer between the support and the electrochemically active coating, wherein the interlayer consists of titanium carbide and/or titanium boride and is applied to the support by flame or plasma spraying. Process for producing these electrodes and their use in an electrochemical cell for producing chlorine or chromic acid.

Abstract: The invention relates to a process for the electrochemical preparation of chlorine from aqueous solutions of hydrogen chloride in an electrolysis cell, comprising an anode chamber and a cathode chamber, the anode chamber being separated from the cathode chamber by a cation exchange membrane, the anode chamber containing an anode and the cathode chamber a gas diffusion cathode, and the aqueous solution of hydrogen chloride being passed into the anode chamber and an oxygen-containing gas into the cathode chamber, and the oxygen pressure in the cathode chamber being at least about 1.05 bar.

Abstract: A process for electrolyzing an aqueous solution of hydrochloric acid to chlorine in an electrochemical cell provided with an anode compartment and a cathode compartment including at least one gas diffusion cathode comprising an electrically conductive web provided on at least one side thereof with a coating of a catalyst for the electroreduction of oxygen comprising rhodium sulfide and optionally containing at least one fluorinated binder incorporated therein, comprising introducing aqueous hydrochloric acid containing contaminant species into the anode compartment and oxygen into the cathode compartment while impressing a direct electric current on the cell.