Abstract: The present invention provides an electrochemical gas sensor that can restrict to the extent possible interference errors.

Abstract: Disclosed herein is a gas diffusion electrode comprising a reaction layer and a gas diffusion layer attached to each other characterized in that a plurality of apertures or a concave convex surface is provided on or through the electrode to facilitate the flowing of an electrolyte. In this electrode, a large volume of an electrolyte and a gas can flow even though the interelectrode distance is small so that a reaction can be promoted to elevate the efficiency.

Abstract: Disclosed is a bubble collection type gas electrode having projections for collecting gas bubbles on the surface of the electrode. This electrode provides a sufficient contact between the bubbles and the gas diffusion layer so that the bubbles are likely to permeate the gas diffusion layer to reach the interface between the gas diffusion layer and a reaction layer so that an amount of the bubbles required for effecting the reaction may be supplied to obtain a satisfactory current density. The electrode may comprise a reaction layer having a plurality of projections, without a gas diffusion layer.

Abstract: Disclosed herein is a process for preparing a reaction layer of a gas permeable electrode which comprises mixing carbon powder and a hydrophobic binding agent, hot-pressing the mixture and cooling the mixture under the hot-pressing conditions or immediately after the hot-pressing. The reaction layer prepared according to the present invention possesses connected electrolyte passages and gas passages so that all the electrolyte penetrates the electrolyte passages and all the gas penetrates the gas passages, whereby excellent contact efficiency is obtained so as to achieve improved catalyst performance.

Abstract: Disclosed herein is a gas permeable member, in particular a gas permeable electrode, carrying a metal complex on a reaction layer thereof. A central metal of the complex may be selected from lead, chromium, iron, cobalt, nickel, copper, zinc, platinum, palladium, manganese, tin, vanadium or the like. The selectivity of a reaction employing the gas permeable member depends on the central metal so that the gas permeable member can be employed in a wide range of applications including electrolytic reduction of carbon dioxide by suitably selecting the central metal of the complex.The complex, for instance a Pc-complex, may be deposited from sulfuric acid by diluting the sulfuric acid by water to be uniformly dispersed in the reaction layer.

Abstract: A method of electrolytically producing an organic compound is disclosed, wherein an organic solvent and an electrolyte which is dissolved therein is placed in an anodic or cathodic chamber. The chambers are separated by a semi-permeable membrane. At least one of the electrodes is a gas permeable electrode which includes a reaction layer joined together with the gas permeable layer. The reaction layer is composed of minute hydrophilic and hydrophobic carbon black, and the gas permeable layer is composed of minute hydrophobic carbon black.

Abstract: Enclosed herein is an apparatus for converting an ionic valence number which comprises a gas permeable membrane comprising a catalyst-supporting reaction layer and a hydrophobic gas permeable layer having fine pores; a solution chamber retaining an aqueous solution containing an ion, and the respective supply port and discharge port for the supply and the discharge of the aqueous solution containing the ion, which are located on the reaction layer side of the gas permeable membrane; and a gas chamber retaining an oxidizing gas or a reducing gas, and the respective supply port and discharge port for the supply and the discharge of the oxidizing or reducing gas, which are located on the gas permeable layer side of the gas permeable membrane.

Abstract: Disclosed herein are processes for preparing a raw material dispersion and raw material powders for producing reaction layers of a gas permeable electrode. The raw materials are prepared in one aspect of the invention by mixing fine particles containing a surface-active agent, freezing the mixture to a temperature the surface-active agent loses at least part of its function and then thawing out the same. The resulting material exhibits superior catalytic performance because the particles are dispersed uniformly by lack of the function of surfaceactive agent at the time of freezing.The raw materials are prepared in another aspect of the invention by mixing hydrophilic minute particles coated with ion exchange resin, PTFE and hydrophobic fine powders.

Abstract: Enclosed herein is an apparatus for converting an ionic valence number which comprises a gas permeable membrane comprising a catalyst-supporting reaction layer and a hydrophobic gas permeable layer having fine pores; a solution chamber retaining an aqueous solution containing an ion, and the respective supply port and discharge port for the supply and the discharge of the aqueous solution containing the ion, which are located on the reaction layer side of the gas permeable membrane; and a gas chamber retaining an oxidizing gas or a reducing gas, and the respective supply port and discharge port for the supply and the discharge of the oxidizing or reducing gas, which are located on the gas permeable layer side of the gas permeable membrane.

Abstract: A process for reducing an uranyl salt solution to an uranous salt solution employing a gas diffusion membrane comprising a reaction layer and a gas supply layer. The uranyl salt solution can be reduced to the corresponding uranous salt solution in the reaction layer of the membrane by a hydrogen gas supplied from the gas supply layer with the reduced power consumption.

Abstract: Disclosed herein is a gas permeable electrode which comprises a gas permeable layer and a reaction layer, the reaction layer comprising hydrophobic portions and hydrophilic portions. Electrolyte penetrates into the reaction layer and does not penetrate into the gas permeable layer, and only the gas produced on the electrode and the gas supplied penetrate into the gas permeable layer. The gas can be released from the rear side of the electrode and the reaction surface thereof is never covered with the gas.

Abstract: Disclosed herein is a gas sensor comprising a membrane for gas sensing which comprises a selective gas permeable membrane and a reaction layer attached thereto; and a counter electrode separated from the reaction layer of the membrane across an electrolyte; the reaction layer having the function of an electrode and comprising fine hydrophilic portions and fine hydrophobic portions.The specific gas in mixed gases having permeated the selective gas permeable membrane is immediately dissolved in the electrolyte having penetrated into the reaction layer and is ionized and the ion in the electrolyte moves to the counter electrode closely positioned to the reaction layer so that the specific gas concentration can be detected by means of the voltage difference or the like.

Abstract: Disclosed herein are processes for preparing a raw material dispersion and raw material powders for producing reaction layers of a gas permeable electrode. The raw materials are prepared in one aspect of the invention by mixing fine particles containing a surface-active agent, freezing the mixture to a temperature at which the surface-active agent loses at least part of its function and then thawing out the same. The resulting material exhibits superior catalytic performance because the particles are dispersed uniformly by the lack of function of the surface-active agent at the time of freezing.The raw materials are prepared in another aspect of the invention by mixing hydrophilic minute particles coated with an ion exchange resin, PTFE and hydrophobic fine powders.

Abstract: The present invention is a method and an apparatus for electrolyzing zinc.The method comprises vertically disposing a rotatable disk made of an electrically conductive metal functioning as a cathode at least of which an outer periphery has an insulation covering; immersing the lower portion of the disk into an electrolyte; disposing a circular arc shaped gas permeable electrode functioning as an anode to be closely opposed to the lower portion of the expressed portion of the both sides of the rotatable disk in the electrolyte; operating the electrolysis with the supply of hydrogen; and peeling off the zinc foil deposited onto the exposed portion of the both sides of the rotatable disk with rotation of the disk. This method can be modified by replacing the rotatable disk with a rotatable drum.

Abstract: An electrode device for an electromagnetic fluid flow apparatus, comprising a pair of electrodes which face a pathway of an electrical conductive fluid, and a magnet which faces the pathway and effects a magnetic field in a direction perpendicular to the flow direction of the electrical conductive fluid and to a straight line connecting the two electrodes. Each electrode is made of a hydrophobic carrier with pores of at most 1 .mu.m pore size, the hydrophobic porous carrier having electrical conductivity, gas permeability and liquid impermeability. A gas generated from the electrode may be discharged from the rear surface of the electrode to the outside without releasing from the surface of the electrode into the electrical conductive fluid.

Abstract: Disclosed herein is a halogen cell of which a positive electrode and/or a negative electrode is a gas permeable electrode. The gas permeable electrode preferably comprises a hydrophilic layer and a gas permeable layer. Since, in this halogen cell, the decrease of the electrode surface area can be prevented, and the desired gas can be rapidly supplied to the electrode, the quantity of charge is increased and the charging time is reduced.Also disclosed herein is a halogen cell of which a positive electrode and/or negative electrode comprises finely divided hydrophilic portions and hydrophobic portions. In this halogen cell, the quantity of charge and the charging time are also improved.