Abstract: The present invention relates to processes for producing fluorine-containing compounds by means of precipitation reactions from solutions containing fluoride ions wherein the pH value is determined using an electrochemical measuring chain and to electrochemical measuring chains for determining pH values.

Abstract: The invention relates to a method for producing electrically conducting nickel oxide surfaces made of nickel-containing material. According to the method, the nickel surface is first degreased and is then roughened for approximately ten minutes in a solution containing about one percent of hydrochloric acid, the process being accelerated by adding hydrogen peroxide solution, resulting in the electrolyte turning green. The nickel surface is briefly wetted, the nickel material is introduced into a solution of 3.5 molar lye to which about ten percent of hydrogen peroxide is added and is kept therein for ten minutes, and the resulting nickel hydroxide surface is dehydrated in a subsequent thermal process and is then further oxidized to obtain nickel oxide. The invention further relates to a conductive boundary layer that is produced according to the method, the electrodes therefrom, and the use thereof in chlorine-alkali electrolysis processes, in fuel cells and storage batteries.

Abstract: An electrolysis cell includes an inner chamber containing a stack of porous anode and cathode plates with separators therebetween. Electrolyte is circulated through the porous anodes and cathodes in the inner chamber to generate hydrogen and oxygen gas. A plurality of electrolysis cells can be mounted together to form an electrolyzer unit.

Abstract: The invention relates to a method for the production of a gas diffusion electrode from a silver catalyst on a PTFE-substrate. The pore system of the silver catalyst is filled with a moistening filling agent. A dimensionally stable solid body having a particle size greater than the particle size of the silver catalyst is mixed with the silver catalyst. Said compression-stable mass is formed in a first calendar in order to form a homogenous catalyst band. In a second calendar, an electroconductive discharge material is embossed in the catalyst band, and heating takes places between the first and the second calendar by means of a heating device, wherein at least parts of the moistened filling agent are eliminated. The invention also relates to a gas diffusion electrode which is produced according to said method.

Abstract: The invention relates to a method for producing electrically conducting nickel oxide surfaces made of nickel-containing material. According to said method, the nickel surface is first degreased and is then roughened for approximately ten minutes in a solution containing about one percent of hydrochloric acid, said process being accelerated by adding hydrogen peroxide solution, resulting in the electrolyte turning green. The nickel surface is briefly wetted, the nickel material is introduced into a solution of 3.5 molar lye to which about ten percent of hydrogen peroxide is added and is kept therein for ten minutes, and the resulting nickel hydroxide surface is dehydrated in a subsequent thermal process and is then further oxidized to obtain nickel oxide. The invention further relates to a conductive boundary layer that is produced according to said method, the electrodes therefrom, and the use thereof in chlorine-alkali electrolysis processes, in fuel cells and storage batteries.

Abstract: With the help of a method for production of a gaseous diffusion electrode from a silver catalyst on PTFE-substrate, it is endeavored to achieve results which can be reproduced, by avoiding the disadvantages of the state-of-the-art technology, whereby this is achieved in that the porous system of the silver catalyst is filled with a wetted fluid; a dimension-stable solid body with a grain size above that of the silver catalyst is mixed below the silver catalyst; the thus compression-stable mass is shaped into a homogenous catalyst band in a calender; and in a second calender step, an electrically conductive conductor material is imprinted into the catalyst band.

Abstract: An electrolysis cell includes an inner chamber containing a stack of porous anode and cathode plates with separators therebetween. Electrolyte is circulated through the porous anodes and cathodes in the inner chamber to generate hydrogen and oxygen gas. A plurality of electrolysis cells can be mounted together to form an electrolyzer unit.

Abstract: With the help of a method for production of a gaseous diffusion electrode from a silver catalyst on PTFE-substrate, it is endeavoured to achieve results which can be reproduced, by avoiding the disadvantages of the state-of-the-art technology, whereby this is achieved in that

Abstract: An electrolysis cell includes an inner chamber containing a stack of porous anode and cathode plates with separators therebetween. Electrolyte is circulated through the porous anodes and cathodes in the inner chamber to generate hydrogen and oxygen gas. A plurality of electrolysis cells can be mounted together to form an electrolyzer unit.

Abstract: An electrochemical gas sensor has a first gas diffusion electrode for a first reaction gas, which is inactive with respect to a second reaction gas at least in a first potential window, and a second gas diffusion electrode for the second reaction gas, which is active with respect to the second reaction gas at least in a second potential window for measuring two different gases in gas mixtures in a casing. The two gas diffusion electrodes are electronically isolated from one another, but electrically connected electrolytically to a reversibly loadable electrode and have contacts for connecting external closing circuits for adjusting the cell currents. The gas mixture is fed to the gas diffusion electrodes in series or parallel. The casing containing the electrodes is, in particular, in the form of a button cell. The reversibly loadable electrode is a Cu/CuO, Zn/ZnO or hydrogen electrode. The gas diffusion electrodes have a porous structure based on carbon or have a porous silver structure.

Abstract: A method for determining relative amounts of O2 and N2O in gas mixtures by quantitative electrochemical reaction including feeding a gas mixture containing O2 and N2O to a zinc-air cell having electrodes connected to a circuit consisting of a plurality of diodes and resistors, which circuit is set to have an electrochemical working range corresponding to each of the O2 and N2O; and measuring current flowing in the respective working range to determine the relative proportions of O2 and N2O in the gas mixture. An electrochemical cell including a casing capable of containing a gas mixture, including O2 and N2O a zinc-air cell in the casing, and a circuit connected to electrodes of the zinc-air cell, the circuit containing a plurality of diodes, resistors and tap points; means for measuring current to determine the relative proportions of O2 and N2O in the gas mixture.