Abstract: A method and apparatus for water electrolysis is described, using an electrolytic cell comprising an anode compartment, a cathode compartment, and a diaphragm separating the anode and cathode compartments, comprising the steps of electrolyzing water to evolve oxygen or an ozone-containing oxygen gas in the anode compartment and hydrogen in the cathode compartment, thereby resulting in a net transfer of electrolyte from the anode compartment to the cathode compartment through the diaphragm, and recycling electrolyte from the cathode compartment to the anode compartment.

Abstract: A gas diffusion electrode comprisinga porous sheet substrate, at least the surface of which is formed by silver;a reaction layer formed on a first surface of the substrate, comprising a porous silver layer and a mixed layer further comprising a hydrophilic material and a hydrophobic material, the mixed layer being formed on a surface of the porous silver layer; and,a gas diffusion layer formed on a second surface of the substrate, comprising a hydrophobic material.The gas diffusion electrode can be stably used for, e.g., sodium chloride electrolysis for extended periods of time even under severe conditions.

Abstract: A method for brine electrolysis using a gas electrode and an electrolytic cell therefor, in which gas electrode 31 permeable to gas and liquid is arranged in cathode chamber 24 in contact with ion-exchange membrane 22. Sodium hydroxide produced on electrode substance 30 of gas electrode 31 easily penetrates the gas electrode and is recovered from the cathode chamber. No sodium hydroxide is produced within the ion-exchange membrane so that penetration of sodium hydroxide into the anode chamber is thereby prevented.

Abstract: A chromium plating method using a plating bath comprising trivalent chromium and an electrode which is an anode comprising an electrode substrate of titanium, tantalum, zirconium, niobium or an alloy thereof, coated with an electrode catalyst comprising at least iridium oxide and, optionally, at least one of titanium, tantalum, niobium, zirconium, tin, antimony, ruthenium, platinum, cobalt, molybdenum, tungsten or an oxide thereof. The anode may be placed directly in the chromium plating bath or may be placed in an anode chamber partitioned from the chromium plating bath with an ion-exchange membrane. The chromium plating method may be a barrel plating method.

Abstract: A process for producing a gas electrode is disclosed, comprising sintering a mixture of carbon powder and a fluorine resin powder to form a sheet as a gas electrode base, coating one side of the sheet base with an organic solution prepared by dissolving a platinum group metal salt in an organic solvent capable of forming an organic complex with the metal salt, drying the coating layer, and calcining the coating layer at a temperature of from 250.degree. to 380.degree. C. in an inert atmosphere to reduce the platinum group metal oxide thereby forming a catalyst layer on the sheet base. Reduction (calcination) of the platinum group metal salt can be effected without using dangerous hydrogen gas and without being accompanied by decomposition of the fluorine resin and provides a uniform catalyst layer comprising fine platinum particles having a large surface area with a minimized thickness.

Abstract: The instant invention relates to a method for manufacturing an electrolytic electrode comprising a core material made of a valve material, forming a plasma flame-coated layer containing the oxides of titanium and tantalum on the surface of the core material, forming an interlayer containing platinum and the oxides of titanium and tantalum on the surface of the plasma flame-coated layer, forming an .alpha.-lead dioxide layer on the interlayer and forming a .beta.-lead dioxide layer on the .alpha.-lead dioxide layer.

Abstract: An insoluble electrode structural material comprising a tabular or curved electrode base plate having at least one thin plate-form insoluble metal electrode detachably fixed to at least a part of the surface of the base plate.

Abstract: The present invention is intended to prevent the formation of impurities such as chlorate in electrolysis using the ion exchange membrane method, without resorting to the addition of hydrochloric acid to counter the migration of alkali hydroxide from the cathode compartment to the anode compartment. The method of the present invention includes feeding a portion of an aqueous solution of an alkali chloride (as the raw material) into an auxiliary electrolytic cell of the cation exchange membrane type in which the anode is a hydrogen gas electrode, thereby effecting electrolysis to generate hydrochloric acid in the anode compartment, and then feeding the hydrochloric acid-containing aqueous solution of alkali chloride into the main electrolytic cell, thereby neutralizing the alkali hydroxide which migrates from the cathode compartment.

Abstract: Disclosed are a method for treatment with ozonized water which comprises feeding primary pure water to an ultrapure-water producing device containing at least a polisher to convert the primary pure water to ultrapure water, injecting an ozone-containing gas into the ultrapure water to produce ozonized water, sending the ozonized water to a point of use, using the ozonized water for treatment, and circulating the resulting spent ozonized water to the ultrapure-water producing device for reuse or discharging the spent water, wherein the method further comprises supplying a hydrogen-containing gas to the spent ozonized water at a point downstream from the use point to remove residual ozone from the ozonized water, a method for the ozone sterilization of ultrapure water which comprises feeding primary pure water from a primary-pure-water tank to an ultrapure-water producing device containing at least a polisher to convert the primary pure water to ultrapure water, sending the ultrapure water to a use point throug

Abstract: A process for producing an electrically conductive mixed oxide comprises sintering a power mixture comprising from 30 to 98% by weight of titanium oxide, in terms of the amount of titanium based on the total amount of all the metallic elements, from 1 to 10% by weight of at least one of titanium metal and titanium hydride, in terms of the amount of titanium based on the total amount of all the metallic elements, and from 1 to 60% by weight of at least one of tantalum oxide and niobium oxide, in terms of the amount of tantalum, niobium, or tantalum and niobium based on the total amount of all of the metallic elements. The process provides a sintered solid comprising titanium, at least one of tantalum and niobium, and a stoichiometrically deficient amount of oxygen.

Abstract: The electrolytic cell 1 for producing alkali hydroxide or hydrogen peroxide is divided into the anode compartment 3 and the cathode compartment 4 by the cation exchange membrane 2. The cathode compartment 4 is further divided by the anion exchange membrane 6 into the solution compartment 7 containing a concentrated aqueous solution of alkali hydroxide and the gas compartment accommodating the gas cathode 8. The anion exchange membrane 6 prevents the gas cathode 8 from coming into direct or indirect contact with the aqueous solution of alkali hydroxide. This leads to the extended life of the gas cathode. The above-mentioned arrangement is effective in large-sized electrolytic cells. Thus, the present invention can be applied to industrial electrolysis which has never been achieved with the conventional gas electrode.

Abstract: The underwater propulsion apparatus, which is mounted on a ship, has the anode and cathode electrodes including an anode compartment and cathode compartment whose electrode materials are separated from seawater in a central duct by the ion exchange membranes so that they are protected from poisoning by seawater. In the method utilizing the apparatus, the anode compartment and cathode compartment are supplied with moist hydrogen and moist oxygen, respectively, so as to substantially suppress the evolution of gas in the duct, which lowers the thrusting force.

Abstract: The present invention relates to an electrolytic electrode comprising a core material made of a valve metal, a dense electrically conductive tin oxide layer formed on the core material, an .alpha.-lead dioxide layer formed on the tin oxide layer, and a .beta.-lead dioxide layer formed on the .alpha.-lead dioxide layer. The present invention also relates to a method for preparing the electrolytic electrode.

Abstract: A process of producing a metallic foil by electrolysis by depositing the metallic foil on a cathode by electrolysis from a sulfuric acid acidic solution is disclosed, which comprises using an electrode having a coating of an electrode active material containing a platinum group metal oxide as an anode and carrying out the electrolysis in an electrolyte containing from 1 to 20 ppm of a lead component when a fluorine component does not exist in the electrolyte or an electrolyte containing from 0.2 to 1 ppm of a fluorine component and from 0.1 to 20 ppm of a lead component when a fluorine component exists in the electrolyte. The life of the electrode can be prolonged and a metallic foil can be stably produced by electrolysis for a long period of time by preventing the lead component(s) derived from the raw material from mixing into the metallic foil.

Abstract: Disclosed is an electrode structure for ozone production which comprises a perfluorocarbon sulfonic acid-based ion-exchange membrane as a solid electrolyte and an anode placed on one side of the solid electrolyte and having a lead oxide as an electrode catalyst, wherein a porous, perfluorocarbon sulfonic acid-based ion-exchange resin layer is formed between the electrolyte and the anode. A process for producing the electrode structure for ozone production is also disclosed, which comprises coating one side of a perfluorocarbon sulfonic acid-based ion-exchange membrane as a solid electrolyte with a liquid, perfluorocarbon sulfonic acid-based ion-exchange resin or with a suspension of ion-exchange resin powder, heating-treating the liquid or suspension-formed ion-exchange resin coating to form an ion-exchange resin layer, and then positioning an anode so as to keep it in close contact with the ion-exchange resin layer, the anode having a lead oxide as an electrode catalyst.

Abstract: The present invention relates to an electrolytic electrode comprising a core material made of a valve metal, a plasma flame-coated layer containing the oxides of titanium and tantalum formed on the surface of the core material, an interlayer containing platinum and the oxides of titanium and tantalum formed on the surface of the plasma flame-coated layer, an .alpha.-lead dioxide layer formed on the interlayer, and a .beta.-lead dioxide layer formed on the .alpha.-lead dioxide layer. The present invention also relates to a process for the manufacture thereof.

Abstract: The present invention relates to an electrolytic electrode comprising a metallic core material, a lead plating layer formed on the surface of the metallic core material, an .alpha.-lead dioxide layer formed on the surface of the lead plating layer, and a .beta.-lead dioxide layer formed on the .alpha.-lead dioxide layer. The present invention also relates to methods for the preparation thereof.

Abstract: An electrolytic electrode substrate comprises an electrically conductive substrate and, formed on the surface of the electrically conductive substrate, an oxide layer having a thickness of from 10 to 200 .mu.m, wherein the oxide in the oxide layer comprises a non-stoichiometric composition containing oxygen and at least one metal selected from the group consisting of titanium, tantalum, and niobium. An advantage of the electrode substrate is that it is stable when used in electrolytic processes involving a reversal of current flow. Further, the electrode substrate is stable in the presence of corrosive substances such as a fluorine.

Abstract: An electrolytic ozone generating apparatus comprising a closely adhered electrode structure of(i) an anode composed of an electrically conductive porous material carrying an ozone generating catalyst,(ii) a perfluorocarbonsulfonic acid ion-exchange membrane which is a solid electrolyte, and(iii) a cathode composed of a gas electrode carrying a catalyst, andmeans for supplying an oxygen-containing gas to the cathode side,wherein the gas electrode as the cathode has a hydrophilic property and a hydrophobic property and carries a catalyst unevenly distributed therein at the ion-exchange membrane side, and a process for generating ozone using the apparatus. The electrolysis is conducted while supplying an oxygen-containing gas to the cathode side.

Abstract: An electrolytic electrode comprising a substrate made of a valve metal, an intermediate layer formed on a surface of the substrate containing an oxide of at least one metal selected from the group consisting of niobium, tantalum, titanium, and zirconium, and a coating layer formed on the intermediate layer containing an iridium-tantalum mixed oxide and platinum. In separate embodiments of the invention, the intermediate layer may contain platinum and/or a stabilizing layer formed on the coating layer containing an oxide of at least one metal selected from the group consisting of tin, titanium, tantalum, zirconium, and niobium.