Abstract: A method and apparatus for water treatment. The method comprises supplying an oxygen-containing gas to cathode 6 to yield hydrogen peroxide, supplying an inorganic acid to anode 5 through an acid solution addition opening 4 to yield an oxidation product, e.g., hypochlorous acid, and using both the hydrogen peroxide and oxidation product thus generated to treat a liquid to be treated. The atmosphere around the cathode surface is kept neutral to acidic due to the acidity of the coexisting oxidation product to thereby inhibit the deposition of metal hydroxides.

Abstract: An electrochemical treating apparatus comprising an electrolytic cell comprising an anode and a cathode spaced apart from the anode, the anode including an electrode material made of diamond and the cathode including an electrode material made of diamond. Also disclosed is an electrochemical treating method for electrochemically decomposing a substance contained in a gas or solution, which comprises introducing a gas or solution containing a substance to be treated into the electrolytic cell, passing an electric current through the electrolytic cell, and recovering a treated gas or solution. In a preferred embodiment, the electrolytic cell comprises an anode including an electrode material made of diamond, a cathode including an electrode material made of diamond and an ion exchange resin or an ion exchange membrane as an electrolyte disposed between the anode and the cathode.

Abstract: An activated cathode comprising an electrically conductive substrate, an interlayer comprising a nickel oxide formed on the surface of the electrically conductive substrate, and a catalyst layer containing at least one lanthanum component selected from oxides and hydroxides of lanthanum metals and at least one platinum component selected from platinum metals and silver and oxides and hydroxides thereof formed on the interlayer. A process for the preparation of an activated cathode is also disclosed which comprises forming an interlayer comprising a nickel oxide on the surface of an electrically conductive substrate, and then forming a catalyst layer containing at least one lanthanum component selected from oxides and hydroxides of lanthanum metals and at least one platinum. component selected from platinum metals and silver and oxides and hydroxides thereof on the surface of the interlayer.

Abstract: A method of reducing nitrous oxide which comprises introducing nitrous oxide into a reaction chamber disposed in contact with an electrolytic chamber having an anode and a cathode comprising a hydrogen-absorbing material, the cathode serving as a diaphragm separating the reaction chamber and the electrolytic chamber, and contacting the nitrous oxide with the diaphragm to thereby continuously reduce the nitrous oxide with hydrogen atoms electrolytically generated on the cathode, absorbed by the hydrogen-absorbing material and passing through the diaphragm. The cathode preferably has catalyst comprising a platinum group metal black deposited on the side of the cathode opposite the anode. Also disclosed is an electrolytic cell for the reduction of nitrous oxide partitioned with a diaphragm into an electrolytic chamber having an anode and a reduction reaction chamber, the diaphragm comprising a hydrogen-absorbing material, and the side of the diaphragm facing the electrolytic chamber serving as a cathode.

Abstract: A cathode assembly comprising a cathode, an ion-exchange membrane, and an electroconductive porous member permeable to gas and liquid sandwiched between the cathode and the membrane. The porous member may have, deposited on a part thereof, a catalyst active in hydrogen generation. The porous member preferably is in the form of a plate, sheet, fibers, web, paper, net, or sinter of any of these, and comprises at least a carbonaceous material and has a thickness of from 0.05 to 5 mm and a porosity of from 10 to 95%. Also disclosed is a method of reactivating a cathode assembly, which comprises conducting electrolysis using the cathode assembly until its activity decreases, and then depositing a catalyst active in hydrogen generation on the porous member.

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 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 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 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: 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: The present invention is directed toward an electrolytic ozonier for treating ozone-containing waste gas and a method of treating ozone-containing waste gas using the ozonier, wherein the method includes evolving oxygen and ozone in an anode compartment of an electrolytic cell by electrolysis of water while evolving hydrogen in a cathode compartment; directing the evolved hydrogen into a waste gas treating section that contains a waste gas decomposition catalyst so as to convert the hydrogen to a harmless form by means of the catalyst; bringing the oxygen and ozone into contact with a medium to be treated in an ozone contactor so as to treat the medium; and subsequently directing waste gas containing oxygen and ozone produced as a result of treatment of the medium into the waste gas treating section where they are brought into either direct or indirect contact with the catalyst so that the ozone in the waste gas is converted into a harmless form.

Abstract: A method and apparatus for water treatment is described, using electrolytic zone, which comprises electrolyzing water to generate an ozone-containing gas in the anode compartment of an electrolytic cell, separating the ozone-containing gas from the anolyte, and contacting the separated ozone-containing gas with the water to be treated said water to be treated being different than the water for electrolysis.

Abstract: A cathode for electrolysis, particularly of a sodium chloride aqueous solution by an ion-exchange membrane method, and a process for producing the same, the cathode comprising a conductive base having a nickel surface and having provided thereon (a) at least one platinum group component selected from the group consisting of a platinum group metal, a platinum group metal oxide, and a platinum group metal hydroxide, and (b) at least one cerium component selected from the group consisting of cerium, cerium oxide, and cerium hydroxide, retaining a markedly reduced hydrogen overpotential for an extended period of time and exhibiting excellent resistance to impurities in the electrolytic solution.

Abstract: A bipolar-electrode electrolytic cell is disclosed, which is to be used in electrolysis of an electrolytic solution having a high electric resistance and including at least two diaphragms positioned to form a plurality of electrode compartments comprising two outer compartments defined between the side walls of the electrolytic cell and the diaphragms positioned closest to the cell walls having a single electrode and at least one electrode compartment having two same-polar electrodes on both sides thereof, each of said electrodes being placed on a diaphragm such that different-polar electrodes are positioned at opposing sides of the diaphragm, wherein the distance between same-polar electrodes within the same compartment is sufficiently large such that electrolysis therebetween does not substantially occur and wherein two of said electrodes at the terminal ends of the series connected electrolytic cell, an anode and a cathode, being further electrically connected to an anode collector and a cathode collector,

Abstract: The present invention is directed toward an electrolytic cell for treating fluids with gases that are evolved by electrolysis comprising an anode compartment separated from a cathode compartment by a diaphragm, and a gas-permeable and liquid-impermeable window formed in the anode and the cathode compartment, or formed in the anode or the cathode compartment, wherein the window is formed such that a gas evolved in the anode or cathode compartment or gases evolved in these two compartments are allowed to pass through the window to make contact with a fluid to be treated, said fluid being located outside said electrolytic cell, thereby treating the fluid.

Abstract: Electrode structures of solid polymer electrolyte type for use in electrolysis are disclosed, (i) in which an adhering layer containing fine particles loaded with a .beta.-lead dioxide powder is formed on one surface of an ion-exchange membrane serving as a solid polymer electrolyte, and an electrodeposited layer of lead dioxide being formed on the surface of the adhering layer, and (ii) in which an electrodeposited layer of lead dioxide having dispersed therein fine particles loaded with a .beta.-lead dioxide powder is formed electrolytically between an ion-exchange membrane serving as a solid polymer electrolyte and a current collector positioned close to the ion-exchange membrane, to thereby form a unitary assembly. The present electrode structures are useful for production of ozone by electrolysis of water and for production of peroxides by electrolysis of aqueous solutions.

Abstract: An electrode catalyst comprising a lead dioxide electrically deposited layer, the layer having particles containing .beta.-lead dioxide powder dispersed therein, and a method for producing the electrode catalyst are disclosed. The particles contain .beta.-lead dioxide powder and optionally an electrolytic cocatalyst selected from PTFE, agar, gelatin, a perfluoro ion exchange resin and the like. The present electrode catalyst is useful for production of ozone by electrolysis of water and for production of peroxides by electrolysis of aqueous solutions.

Abstract: A cathode for electrolysis, particularly of a sodium chloride aqueous solution by an ion-exchange membrane method, and a process for producing the same, the cathode comprising a conductive base having a nickel surface and having provided thereon (a) at least one platinum group component selected from the group consisting of a platinum group metal, a platinum group metal oxide, and a platinum group metal hydroxide, and (b) at least one cerium component selected from the group consisting of cerium, cerium oxide, and cerium hydroxide, retaining a markedly reduced hydrogen overpotential for an extended period of time and exhibiting excellent resistance to impurities in the electrolytic solution.

Abstract: An electrolytic cell for electrolysis of sea water comprisinga housing having an opening at the bottom and top of the housing for in-flow of sea water and out-flow of electrolyzed sea water, respectively;a plurality of flat plate-like anodes vertically disposed in the housing with the major surface area of the anodes being parallel to the flow of sea water through the cell;a plurality of flat plate-like cathodes vertically disposed in the housing with the major surface area of the cathodes being parallel to the flow of sea water through the cell;an outwardly projecting portion for passing an electric current provided at the lower side edge of each of the anodes;an outwardly projecting portion for passing an electric current provided at the upper side edge of each of the cathodes;an electric current-passing plate secured to the lower portion of the housing and connected to the portions for passing an electric current to each of the anodes; andan electric current-passing plate secured to the upper portion of th