Abstract: Electrolyzer comprising at least one single electrolyzer element which comprises at least one anode compartment with an anode, one cathode compartment with a cathode and one ion exchange membrane arranged between the anode and the cathode compartments, with the anode and/or cathode being a gas diffusion electrode. A gap is provided between the gas diffusion electrode and the ion exchange membrane, with an electrolyte inlet arranged at the upper end of the gap and an electrolyte outlet at the lower end of the gap and a gas inlet and a gas outlet. The electrolyte outlet extending into a discharge header, and the electrolyte inlet connected to an electrolyte feed tank and having an overflow, the overflow connected to the discharge header, with a coiled hose connecting the electrolyte feed tank with the electrolyte inlet and with a coiled hose connecting the overflow with the discharge header.

Abstract: A process for producing oxygen-consuming electrodes, in particular for use in chloralkali electrolysis, which display good transport capability and storage capability. In the process, a silver oxide-containing sheet-like structure as intermediate is electrochemically reduced. Also disclosed are methods of using these electrodes in chloralkali electrolysis or fuel cell technology or in metal-air batteries, and the fuel cells and metal-air batteries produced.

Abstract: A process for preparing diaryl carbonate and utilizing at least part of the process wastewater by increasing the concentration of the wastewater phases containing sodium chloride for the electrolysis by means of osmotic membrane distillation with simultaneous dilution of the sodium hydroxide solution obtained from the electrolysis for the diaryl carbonate production process (diphenyl carbonate process) is described.

Abstract: A process for wet-chemical production of a catalyst coating on an electrically conductive support for electrodes for chloralkali or hydrochloric acid electrolysis with electrocatalytically active components based on noble metal oxides, in which the catalyst coating is produced by; producing a coating solution or dispersion comprising a precursor compound of a noble metal and/or a metal oxide of a noble metal, and a solvent or dispersant, with addition of one or more acids to the coating solution or dispersion, where the molar ratio of the total of the amounts of acid (in mol) present in the coating solution or dispersion to the sum of the amounts of the metals from the metal-containing components present in the coating solution or dispersion is at least 2:1; applying the coating solution or dispersion to the support; substantially freeing the layer applied of solvent or dispersant by drying; and subjecting the dried layer obtained to a thermal treatment to form the catalyst coating.

Abstract: Electrocatalyst, electrode coating and an electrode for preparing chlorine and process for producing the electrode, the electrocatalyst comprising a noble metal oxide and/or a noble metal of transition groups VIIIa of the Periodic Table of the Elements and at least one finely divided pulverulent oxide of another metal, in which one or more components are doped and the base metal oxide powder is chemically stable in the presence of aqueous electrolytes.

Abstract: In a process for chlorine-alkali electrolysis, use is made of an oxygen depletion cathode. The process is run with a high excess of oxygen. The oxygen needed for this is provided for a device of the gas separation, for example a VPSA plant or an air fractionation plant. The large quantities of oxygen produced lead to considerable costs of the process. According to the invention, the oxygen-rich atmosphere remaining after passing through the process is fed back into the device for gas separation as input gas. The device the gas separation is therefore operated with an oxygen-rich input gas and therefore produces a larger quantity of oxygen-rich gas, which in turn is fed to the oxygen depletion cathode. As a result of the circulation of the gas, the economy of the overall process is increased considerably.

Abstract: The invention relates to an electrochemical cell comprising an anode and a cathode compartment separated by a membrane, housing corresponding electrodes. The anode and the cathode compartments having external walls with frame-type flanged areas in the contact area of both compartments. The flanged areas having mounting bores marking an inner area and an outer area of the electrochemical cell a, gas-diffusion electrode resting on a support system, a porous material resting on the gas-diffusion electrode, and devices for the inlet and outlet of gas and electrolyte. At least one circumferential gasket frame is in the contact area of both compartments, between the frame-type flanged areas of the external walls of both compartments, said gasket resting on the membrane, with the porous material and the gas-diffusion electrode resting on the frame-type cathodic flanged area and the circumferential gasket frame overlapping in this area with the porous material and the gas-diffusion electrode.

Abstract: The invention relates to an electrochemical cell comprising an anode and a cathode compartments, separated by a membrane, having corresponding electrodes; said anode and cathode compartments each having an external wall, flanged areas designed like frames in the contact area of the compartments, and a gas diffusion electrode comprising a liquid-permeable carrier coated with a catalyst material; said gas diffusion electrode featuring an area not coated with catalyst at its bottom edge, said area, at the bottom end of the electrochemical cell, protruding between the flanged areas of the external wall of the cathode compartment and the flanged areas of the external wall of the anode compartment in the contact area of the compartments; a porous material arranged parallel between the gas diffusion electrode and the membrane, and devices for the supply and discharge of gas and electrolyte, with a gas space separated from an electrolyte space by appropriate means.

Abstract: Method for the gastight and liquid-tight installation of oxygen-consuming electrodes in an electrolysis apparatus, and electrolysis apparatus for use in chloralkali electrolysis, in which particular regions are covered with an additional film having a composition comparable to the oxygen-consuming electrodes

Abstract: Electrolyser comprising at least one single electrolyser element which comprises at least one anode compartment with an anode, one cathode compartment with a cathode and one ion exchange membrane arranged between the anode and the cathode compartments, with the anode and/or cathode being a gas diffusion electrode. A gap is provided between the gas diffusion electrode and the ion exchange membrane, with an electrolyte inlet arranged at the upper end of the gap and an electrolyte outlet at the lower end of the gap and a gas inlet and a gas outlet. The electrolyte outlet extending into a discharge header, and the electrolyte inlet connected to an electrolyte feed tank and having an overflow, the overflow connected to the discharge header, with a coiled hose connecting the electrolyte feed tank with the electrolyte inlet and with a coiled hose connecting the overflow with the discharge header.

Abstract: Process for electrolysis of alkali metal chlorides with oxygen-consuming electrodes having specific operating conditions for startup and shutdown, which prevents damage to constituents of the electrolysis cell.

Abstract: Processes for electrolysis of alkali metal chlorides with oxygen-consuming electrodes having startup and shutdown conditions which prevent damage to the constituents of the electrolysis cell.

Abstract: An oxygen-consuming electrode for use in chloralkali electrolysis, having a novel coating, the production thereof, an electrolysis cell comprising the oxygen-consuming electrode and parameters for the startup and shutdown of the electrolysis apparatus, compliance with which prevents damage to the cell.

Abstract: An oxygen-consuming electrode, in particular for use in chloralkali electrolysis, having a novel catalyst coating and also an electrolysis apparatus are described. Furthermore, its use in chloralkali electrolysis, fuel cell technology or metal/air batteries is described. The oxygen-consuming electrode comprises at least a support which in particular is electrically conductive, a layer containing a catalyst and a hydrophobic layer, characterized in that it contains gallium in addition to silver as catalytically active component.

Abstract: The invention relates to a process for production of diaryl carbonate combined with the electrolysis of the resultant alkali metal chloride-containing process wastewater. The process according to the invention makes possible, inter alia, improved utilization in electrolysis of the alkali metal chloride-containing solution obtained in the production of diaryl carbonate.

Abstract: The invention describes an electrode and an electrode coating which are based on a catalyst containing finely divided carbon modifications and noble metal (oxide)s.

Abstract: The present invention relates to an electrode that includes an electrically conducting substrate based on a valve metal having a main proportion of titanium, tantalum or niobium, and an electrocatalytically active coating comprising up to 50 mol % of a noble metal oxide or noble metal oxide mixture and at least 50 mol % of titanium oxide. The coating includes a minimum proportion of oxides of anatase structure determined by a ratio of the signal height of the most intensive anatase reflection in an x-ray diffractogram (CuK? radiation) after subtraction of a linear background to the signal height of the most intensive rutile reflection in the same diffractogram, wherein the ratio is at least 0.6.

Abstract: An improved catalyst coating comprising electrocatalytically active components based on ruthenium oxide and titanium oxide, especially for use in chloralkali electrolysis, is described. A production process for the catalyst coating and a novel electrode is also described.

Abstract: An oxygen-consuming electrode is described, more particularly for use in chloralkali electrolysis, comprising a novel catalyst coating, as is an electrolysis apparatus. Also described is a production process for the oxygen-consuming electrode and the use thereof in chloralkali electrolysis or fuel cell technology. The oxygen-consuming electrode comprises at least an electrically conductive support, an electrical contact site and a gas diffusion layer comprising a catalytically active component, characterized in that the coating at least one fluorinated polymer, silver in the form of silver particles and silver oxide in the form of silver oxide particles, which is produced in a selected precipitation step.

Abstract: An oxygen-consuming electrode is described, more particularly for use in chloralkali electrolysis, comprising a novel catalyst coating based on silver and a finely divided silver oxide, as is an electrolysis apparatus. Also described is a production process for the oxygen-consuming electrode and the use thereof in chloralkali electrolysis or fuel cell technology.