Abstract: An electrochemical cell comprising: (i) an anode half-cell with an anode, (ii) a cathode half-cell with a cathode, (iii) an ion-exchange membrane arranged between the anode half-cell and the cathode half-cell, the anode and/or the cathode comprising a gas diffusion electrode, (iv) a gap between the gas diffusion electrode and the ion-exchange membrane, (v) an electrolyte feed inlet above the gap, (vi) an electrolyte drain beneath the gap, (vii) a gas inlet, (viii) a gas outlet, and (ix) an electrolyte holding vessel comprising an overflow connected with the electrolyte feed inlet.

Abstract: The present invention describes an electrochemical cell, comprising at least an anode half-cell with an anode, a cathode half-cell with a cathode, and an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, the anode and/or the cathode is a gas diffusion electrode. And a gap is provided between the gas diffusion electrode and the ion exchange membrane, and the half-cell with the gas diffusion electrode has an electrolyte feed and an electrolyte discharge as well as a gas inlet and a gas outlet. The electrochemical cell preferably has an electrolyte feed that is hermetically connected to the gap.

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 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: A method for the electrolysis of aqueous solutions of hydrogen chloride in order to produce chlorine, characterized in that the following process parameters are maintained for initial operation: the anode half-element is filled with a 5 to 20% strength by weight hydrochloric acid, the concentration of the hydrochloric acid is more than 5% by weight during initial operation, the volumetric flow of the hydrochloric acid through the anode half-element is set in such a way that, at the start of electrolysis, the velocity of the hydrochloric acid in the anode space is from 0.05 cm/s to 0.15 cm/s, the electrolysis is started with a current density of 0.5 to 2 kA/m2, and the current density is then increased continuously or discontinuously until the desired current density is reached.

Abstract: An electrochemical cell comprising: (i) an anode half-cell with an anode, (ii) a cathode half-cell with a cathode, (iii) an ion-exchange membrane arranged between the anode half-cell and the cathode half-cell, the anode and/or the cathode comprising a gas diffusion electrode, (iv) a gap between the gas diffusion electrode and the ion-exchange membrane, (v) an electrolyte feed inlet above the gap, (vi) an electrolyte drain beneath the gap, (vii) a gas inlet, (viii) a gas outlet, and (ix) an electrolyte holding vessel comprising an overflow connected with the electrolyte feed inlet.

Abstract: The invention describes a process for the electrolysis of an aqueous solution of alkali metal chloride, in particular sodium chloride, by the membrane process with an aqueous solution of alkali metal hydroxide, in particular sodium hydroxide, as catholyte, where the temperature of the alkali metal chloride solution in the anode half-element and/or the volume flow rate of the alkali metal chloride solution in the anode half-element are set in such a way that the difference between the temperature of the alkali metal hydroxide solution at the entry into the cathode half-element and the temperature of the alkali metal hydroxide solution at the exit from the cathode half-element are not greater than 15° C.

Abstract: The present invention describes an electrochemical cell, comprising at least an anode half-cell with an anode, a cathode half-cell with a cathode, and an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, the anode and/or the cathode is a gas diffusion electrode. And a gap is provided between the gas diffusion electrode and the ion exchange membrane, and the half-cell with the gas diffusion electrode has an electrolyte feed and an electrolyte discharge as well as a gas inlet and a gas outlet. The electrochemical cell preferably has an electrolyte feed that is hermetically connected to the gap.

Abstract: The invention relates to an electrolysis cell comprising an anode frame (26), an anode (24), a cation-exchange membrane (34), a gas diffusion electrode (32), a current collector (10) and a cathode frame (12), with the anode (24), the cation-exchange membrane (34), the gas diffusion electrode (32) and the current collector (10) being held together elastically so that there is no gap between the individual components anode (24), cation-exchange membrane (34), gas diffusion electrode (32) and current collector (10). The elastic cohesion is preferably achieved by the current collector (10) being elastically fastened to the cathode frame (12) and/or the anode (24) being elastically fastened to the anode frame (26).

Abstract: A method for producing gas diffusion electrodes, in particular for use in electrolysis cells, as well as electrodes and their uses are described. A method of the present invention involves first, a sheet-like structure is produced by means of a pair of rolls by rolling a powder mixture containing at least one catalyst or a catalyst mixture and a binder, and then the sheet-like structure is connected to an electrically conductive catalyst support by rolling by means of a pair of rolls. In one embodiment the clamping force of the rolls is preferably kept constant in the range from 0.2 kN/cm to 15 kN/cm.

Abstract: An electrochemical half-cell, in particular for the electrochemical production of chlorine from aqueous solutions of an alkaline metal chloride, comprising at least

Abstract: The invention concerns an electrochemical half-cell for preparing chlorine from aqueous alkali chloride solutions, comprising an electrode chamber (17) designed to contain an electrolyte. Said half-cell also comprises several gas pockets (26, 27, 28, 29) which are separated from the electrode chamber (17) by a gas-diffusing electrode (5). The invention is characterized in that said half-cell includes a support element (21), for supporting the gas pockets (26, 27, 28, 29), which is adjacent over its entire surface to the rear wall (20) of the pockets (26, 27, 28, 29) or which constitutes the rear wall (20) of said gas pockets (26, 27, 28, 29).

Abstract: The invention relates to a gas diffusion electrode support structure that receives a gas diffusion electrode (10) for an electrochemical reactor. Said support structure has a base structure (8) to whose fin (11) a connecting element is connected via a weld seam (20) in an electrically conductive way. The connecting element is configured as a bent structure and encloses an edge area (15) of the gas diffusion electrode (10). The edge area (15) of the gas diffusion electrode (10), in an external section (32), is not coated, and in an interior section (33) is provided with an electrochemically active coating.

Abstract: An electrochemical half cell comprises a gas diffusion electrode (22) that serves as an anode or cathode and separates an electrode space from a gas space (2). In addition, a number of gas pockets (2) are provided that are formed by the gas diffusion electrode (22) and a rear wall (5). A gas connecting channel (1) that connects two gas pockets to one another is provided through which the gas flows via a gas supply connection (3) into the gas pocket located thereabove. In order to be able to easily detach the connection, the gas supply connection (3) is accessible from the side of the gas diffusion electrode (22).

Abstract: The invention relates to a method for the electrolysis of aqueous solutions of hydrogen chloride, for producing chlorine by means of a gas-diffusion electrode in compliance with set operating parameters.

Abstract: A method for producing gas diffusion electrodes, in particular for use in electrolysis cells, as well as electrodes and their uses are described. A method of the present invention involves first, a sheet-like structure is produced by means of a pair of rolls by rolling a powder mixture containing at least one catalyst or a catalyst mixture and a binder, and then the sheet-like structure is connected to an electrically conductive catalyst support by rolling by means of a pair of rolls. In one embodiment the clamping force of the rolls is preferably kept constant in the range from 0.2 kN/cm to 15 kN/cm.

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 relates to an electrochemical cell suitable for a membrane electrolysis process, comprising (i) at least one anode compartment having a metal electrode, (ii) a cathode compartment having a gas diffusion electrode (iii) and an ion exchange membrane arranged between the anode compartment and the cathode compartment. The metal electrode that functions as an anode is capable of being dipped into an electrolyte during use and is provided with one or more orifices for the passage of gas formed during operation. The metal electrode can optionally be angled and/or curved, and the orifices preferably have guide structures that conduct the gas formed to a side of the metal electrode that faces away from the cathode. The present invention also relates to electrodes per se as well as methods for use of electrodes and electrochemical cells.

Abstract: The invention describes an electrochemical half-cell, in particular for the electrolysis of aqueous solutions of hydrogen chloride, at least comprising a gas space, the gas space having a gas feed and a gas discharge as well as a liquid outlet, and a gas diffusion electrode which rests on an electrically conductive current distributor and makes an electrically conductive contact with the current distributor, the current distributor having a free area in the range from 5 to 65%, preferably from 10 to 60%, particularly preferably from 15 to 50%, based on the total area of the current distributor, and a thickness of from 0.3 mm to 5 mm, preferably from 0.35 to 0.6 mm.