Abstract: Gas diffusion electrodes, gas generating or consuming electrochemical cells utilizing such electrodes, and a method of preparing such electrodes are disclosed. The electrode comprises an electronically conductive porous body defining respective gas and electrolyte contacting surfaces. The electrode is prepared by forming the porous body, disposing the electrolyte contacting surface in contact with an electrolyte, and contacting the gas contacting surface with a gaseous atmosphere. Current is passed through the porous body at a degree of electrode polarization much higher than normal whereby modification of the electrode material is effected. If desired, a catalyst may be incorporated in the electrode and is subjected to pretreatment as well. The inventive electrodes exhibit superior voltage performance under oxygen polarization conditions.

Abstract: Method for the electrolytic preparation of hypochlorite in flowing salt-containing water for the purpose of disinfecting swimming baths, massage baths, drinking water etc. by means of an electrolysis reactor comprising a "scale-retarding" cathode having an open structure and a specific surface of at least 10 cm.sup.2 /cm.sup.3.

Abstract: A method is disclosed for recycling spent potliner carbon from an aluminum reduction cell. The spent potliner is treated so as to avoid the cracking problem normally seen when the potliner is used in substantial amounts in Soderberg anodes.

Abstract: Cathode for use in magnesium production by electrolysis of molten salts. The cathode consists of compact molybdenum, tungsten or alloys of these metals or consists of a substrate coated with molybdenum, tungsten or alloys of these metals. The thickness of the coating is at least 10-20 .mu.m. The substrate can be iron or carbon. Carbon coated with molybdenum, tungsten or alloys of these metals can be used as the cathodic face of a bipolar electrode. The wetting of the cathode by magnesium is improved and the amount of contaminants in the produced metal is reduced.

Abstract: Describes the use of high performance phenol-formaldehyde resins in the fabrication of anodes, cathodes, and electrodes, for use in metallurgy. A carbonaceous aggregate mixed with binder material is formed into a compacted mass in a desired shape, and the resin is permitted to cure to form a self-sustaining shape. Upon carbonization of the shaped, compacted mass, electrodes and other desirable shapes may be produced. Also useful for ramming and tamping mixes. Provide environmentally safe binder replacements for coal tar pitch while providing excellent residual carbon contents and desirable electrical and physical properties.

Abstract: The invention relates to a method of regulating the tar content of precooked anodes intended for the production of aluminum by electrolysis, to an optimum level Bm corresponding to the maximum dry density of the anodes, which utilizes measurements on crude anodes emerging from compaction and without awaiting the results of the cooking process. The method comprises the following repeatedly carrying out of the following sequence of steps:(a) forming a carbonaceous paste containing, by weight, an initial tar content Bo %;(b) forming a number n of anodes from the initial carbonaceous paste, and determining mean dry density by measuring their height H and weight P when they emerge from compaction;(c) forming a further carbonaceous paste containing tar content, .gamma.(Bo+x.sub.o) % where x.sub.o is greater or less than zero;(d) forming a number m of anodes from the second carbonaceous paste and determining the mean dry density .gamma.(Bo+x.sub.o) of the m anodes when they emerge from compaction;(e) comparing .

Abstract: A carbonaceous source material, other than premium petroleum coke is subjected to the action of elemental boron or a boron compound, whereby the highly disordered structure is transformed into one that is very graphitic in an otherwise conventional electrode manufacturing process.

Abstract: Laminated electrodes and a method for their preparation are described, these electrodes being composed of electrically conductive plastic having catalytic particles, composed of a catalyst deposited on supporting particles, pressed partially into the plastic. They can be used as oxygen anodes, for example in the electrolytic recovery of metal from aqueous solutions.

Abstract: An improved multiple layered porous electrode for use in an electrochemical membrane cell is provided having a first perforated support layer, a second layer of fibers, a third layer of fibers less dense than the second layer and a fourth layer of meshed wire cloth.

Abstract: The invention is an electrochemical cell which is useful to reduce oxygen to hydrogen peroxide at a cathode and a process employing the cell. The cell not only avoids the safety hazard of a hydrogen explosion of the prior art cells but also avoids the need for a rigid separating means and cathode.

Abstract: An electrode comprises an outer casing and an inner casing which enclose un-baked electrode paste. A conducting mandrel is placed in the center of the electrode and is in electrical contact with the paste. Electric current passes through the conducting mandrel outwardly through the paste to provide a baked electrode. Slipping shoes engage the outer surface of the baked electrode to support the baked electrode and the unbaked paste. In one embodiment, a thin foil moves with the paste to allow the paste to move downwardly easily with respect to the casings, and in a second embodiment, the casing is oscillated with respect to the paste to prevent adhesion between the paste and the casing walls.

Abstract: The invention relates to a method for the individual marking of precooked anodes used in the production of aluminum by electrolysis in the Hall-Heroult process, and to the anodes produced thereby. These anodes are produced by hot compaction of a carbonaceous paste, and according to the invention, during or immediately after such compaction, a plurality of impressions is formed in the upper part of each anode. The impressions are depressions and/or relief portions, constitute a digital coding for the identification number of each anode, and remain legible until withdrawal of the components of the butt of the worn anode from the electrolysis tank. The marking can be carried out using a binary or ternary code, where the reference plane of the zone of the anode which carries the marking corresponds to a first digit, with other digits corresponding to depressions of a particular depth, depressions of a greater depth, or relief portions.

Abstract: A self-baking electrode includes a pressure chamber for receiving electrode paste under pressure. A centrally located conductor supplies electrical current to the paste, and the paste is baked by passage of the electrical current to form an electrode. The electrode is supported by a support band and is advanced past the support band by supplying paste under pressure to the pressure chamber. The pressure chamber is heated to maintain the paste in a softened state.

Abstract: An insoluble and infusible substrate with a polyacene-type skelatal structure having a hydrogen/carbon atomic ratio of from 0.05 to 0.60 and containing open pores having an average diameter of not more than 10 micrometers, said substrate being a heat-treated product of an aromatic condensation polymer consisting of carbon, hydrogen and oxygen. The substrate, when doped with a dopant, gives an electrically conductive material. When having a specific surface area of at least 600 m.sup.2 /g, the substrate is especially useful as an electrode of an organic cell.

Abstract: The invention is an electrochemical cell which is useful to reduce oxygen to hydrogen peroxide at a cathode. The cell avoids the safety hazard of a hydrogen explosion of the prior art cells. The cell has an added advantage in that the dimensions of the cathode are not limited by hydrostatic pressures or by the capacity of the channels and pores of the cathode.

Abstract: A process and an apparatus for producing a neodymium-iron alloy by electrolytic reduction of neodymium fluoride in a bath of molten electrolyte, consisting essentially of 35-76% by weight of neodymium fluoride, 20-60% by weight of lithium fluoride, up to 40% by weight of barium fluoride and up to 20% by weight of calcium fluoride, conducted between one or more iron cathode and one or more carbon anode.

Abstract: Disclosed herein are an oxygen-cathode for use in electrolysis or an alkali chloride, comprising a current collector made of a compact carbonaceous material, electrode substrate(s) made of a porous carbonaceous material and the catalyst carried on the electrode substrate(s), wherein the electrode substrate(s) and the current collector have been joined together and integrated into one body as carbon, and a process for preparing the oxygen-cathode.

Abstract: Bonded, coherent fibrous web substrates well adopted as cathodic elements for electrolytic cells and advantageously incorporating an electrocatalytic agent, include a web matrix which comprises a plurality of fibers, at least a portion of which comprising electrically conductive fibers, e.g., carbon fibers, said plurality of fibers being coherently bonded together with a fluorine-containing polymer, and said web substrate having a resistivity of up to about 0.4 .OMEGA..cm.

Abstract: An improved multiple layered porous electrode for use in an electrochemical membrane cell is provided having a first perforated support layer, a second layer of fibers, a third layer of fibers less dense than the second layer and a fourth layer of meshed wire cloth.

Abstract: A laminated carbon cathode includes two layers of carbon blocks, i.e. and the upper layer of graphite of graphitised carbon, and a lower layer of a cheaper anthracite carbon. The two layers are so displaced with respect to one another that there are no vertical seams leading straight from the upper surface of the carbon cathode to the its underside. Dividing the cathode into two horizontal layers is combined with the embedding of current-carrying steel conductors in precise grooves between the layers. In order to capitalize on the good electrical conductivity of aluminum, an aluminum extension is friction-welded to each steel conductor as close to a shell enclosing the cathode while at the same time a collar is formed which provides an air-tight seal at the point where the cathode bar enters the side of the shell.

Abstract: The present application relates to an outer shell for electrolytic cell for molten salt electrolysis preferably an electrolytic cell for production of aluminium, wherein the outer shell is made from concrete.The present application further relates to a method for producing a cathode for molten salt electrolysis where the cathode is built up on a form having outer dimensions and shape corresponding to the inner dimensions and shape of the finished cathode, by successively placing on said form bottom carbon blocks, eventual intermediate carbon blocks, sidewall carbon blocks, busbars, and eventual barrier layer and refractory insulation material layers, whereafter an outer shell made from concrete is cast upon the layers of refractory insulation material.

Abstract: An ion exchange membrane electrolyzer having at least one electrolytic cell containing a gas diffusion cathode, a current distributor, an anode supported by a wall of the electrolytic cell housing, and spacing means separating the current distributor which is in contact with said gas diffusion cathode from said ion exchange membrane wherein the force exerted by gas pressure applied to one face of the gas diffusion cathode is transmitted to said anode via said current distributor, and/or said spacing means, and said ion exchange membrane.

Abstract: A prebaked carbon or Soderberg anode for the recovery of aluminum metal from its ores by the process of electrolysis wherein the anode contains comminuted aluminum in an amount of from 0.1 to 2.0 parts by weight per 100 parts by anode material.

Abstract: An improved electrode assembly is disclosed for use in electrolytic cells for producing metal by the electrolysis of a molten-salt electrolyte. The electrode assembly includes at least one anode and cathode disposed within an electrolytic cell in a spaced-relationship to thereby define an inter-electrode space and an effective electrolyte bath area. The parallel, opposed sides of the anode and cathode defining the inter-electrode space of the improved electrode assembly have an offset, sawtooth pattern of triangular peaks and valleys to thereby increase the effective electrode surface area and to facilitate the rapid, effective removal of gas produced during electrolysis from the anode and from the inter-electrode, electrolyte bath area. To further facilitate the removal of such gases, the anode of the present invention includes a uniformly distributed plurality of gas evacuation apertures therethrough.

Abstract: A process is disclosed for the production of a tungsten carbide-activated electrode, particularly an electrode which is utilizable as a cathode, and which consists of an electrically-conductive substrate with an active surface layer of tungsten carbide. The tungsten carbide is adhesively bonded through chemical reaction to the surface of a substrate which is constituted of graphite or a graphite-like material. The graphite-like material is a graphite binder mixture, whose binder material components, other than the graphitic filler granules, are only carbonized, and may not be completely graphited.

Abstract: A catalyst/cocatalyst/organics composition of matter is useful in electrolytically producing hydrogen or electrowinning metals. Use of the catalyst/cocatalyst/organics composition causes the anode potential and the energy required for the reaction to decrease. An electrolyte, including the catalyst/cocatalyst composition, and a reaction medium composition further including organic material are also described.

Abstract: An apparatus used in high pressure electrolytic cell operation which allows a cell to be operated at high pressures while providing balanced interface pressures between circulating liquids and gases. Each liquid and gas compartment in the cell is connected to a holding tank. Gas pressure in the holding tank is allowed to build up to the pressure required for cell operation before it is released. Positive displacement pumps circulate liquids through the cell at a pressure equal to the pressure of gases contained in the holding tanks. Gases are back-pressured into the gas compartments of the cell at a pressure equal to the pressure of the gases contained in the holding tanks thereby balancing the pressures of gases and liquids in the cell while allowing for circulation of the liquids.

Abstract: Dissolved arsenic (III) contaminant is removed from mineral acids, such as hydrochloric acid, by electrolysis using a high surface area cathode having a three-dimensional electrolyte-contacting surface which exposes the electrolyte to electrolysis for a relatively long period of time. The dissolved arsenic is reduced to arsenic metal, which then plates out on the cathode. Dissolved concentrations of arsenic of less than 1 ppm can be achieved using the invention.

Abstract: A method of treating fluids containing impurities by means of an electrochemical reactor consisting of at least one pair of opposed main electrodes, a power source capable of generating an alternating current connected to the main electrodes, and a plurality of auxiliary electrodes disposed between the main electrodes which are uniformly arranged in a mutually close relationship. The auxiliary electrodes may be disposed on the surfaces of nonconductive supports so as to form a macroporous mixed filler layer between the main electrodes. Control of the electrochemical reactions is achieved through the choice of electrocatalytic materials on the surfaces of the auxiliary electrodes and materials dissolved in the fluid to be treated.

Abstract: An aluminum reduction cell having an outer steel shell, thermal and electrical insulation, and an inner lining comprising at least a floor and sidewalls, the improvement which comprises a gap sealant at least in the region of the transition between the floor and sidewalls, the gap sealant comprises a pourable material characterized by a melting point of greater than 1000.degree. C., a density of greater than 2.7 g/cm.sup.3 and a high degree of resistance to molten electrolyte and molten aluminum.

Abstract: The present invention relates to electrodes having fibers which provide large surface areas, high bond strength between the core fibers and metallic coatings thereon, and efficient electrical connections; electro-chemical cells including such electrodes; and processes for forming and utilizing the electrodes and cells of the invention.

Abstract: An apparatus and method for the electronic decomposition of water into its component free radical parts and free electrons. In a cell containing an aqueous fluid, an electromotive force is applied to a positive charge storage core, insulated with semi-conductive material, and a conducting cathodic connector having a limited electrolysis bridge therebetween thereby inducing the formation of an aqueous condenser, the anodic section of which consists of the positive charge storage core insulated with the semi-conductive material. The formed aqueous condenser is subjected to overpotentials at which the dielectric breakdown of water occurs. The free radicals produced by such dielectric decomposition serve to treat most dissolved, suspended or precipitous substances in solution by oxidation/reduction reactions.

Abstract: Disclosed herein are an oxygen-cathode for use in electrolysis of an alkali chloride, comprising a current collector made of a compact carbonaceous material, an electrode substrate made of a porous carbonaceous material and the catalyst carried on the electrode substrate, wherein the electrode substrate and the current collector have been joined together via the mutually facing carbonized surfaces thereof, and a process for preparing the oxygen-cathode.

Abstract: A reduction pot for the production of aluminum by fused salt electrolysis comprises an outer steel shell, thermal insulation and an inner lining essentially of carbon with iron cathode bars embedded in it. The floor insulation comprises at least in part of a mechanically compacted layer of a granular material of ground insulation layers and having essentially a particle size that varies between 0.01 and 8 mm. The sidewalls of the reduction pot contain, up to at most 70% of the height (h) of the cathode bar elements, mechanically compacted granular material from ground insulation layers. Above that the thermally and electrically insulated steel shell is lined with sidewall bricks, and the gap between the sidewall bricks and the floor elements is closed off with the usual ramming mass.

Abstract: A process for the electrolytic deposition of aluminum at low temperatures and low electrical potential in which the anode is the sole source of aluminum and comprises a composite mixture of an aluminous material such as aluminum oxide and a reducing agent. The composite anode is positioned in the electrolyte with at least one active surface of the anode in opposed relationship to but spaced from the surface of the cathode. The greatly increased electrical resistance of the mixture of aluminum oxide and the reducing agent is minimized by passing the anodic current through one or more conductors of low electrical resistivity which extend through the mixture to or approximately to the active reaction face of the mixture in the electrolyte. The position of the ends of said conductors is maintained relative to the reaction face as the mixture is consumed in the electrolysis.

Abstract: In a fuel cell which has an activated carbon-containing anode and an activated carbon-containing cathode and is preferably used for the oxidative treatment of waste waters containing oxygen or oxygen-containing compounds, the cathode has been subjected to partial anodic oxidation in a mineral acid at a potential .epsilon..sub.h of from +1.3 to +10V and then doped with molybdenum(VI) and/or tungsten(VI) and/or vanadium(V) compounds, and the anode has been subjected to partial anodic oxidation in an aqueous mineral acid, cathodically reduced in an aqueous mineral acid and then impregnated with cobalt hydroxide and/or nickel hydroxide and/or copper hydroxide and/or zinc hydroxide, the anode and the cathode being separated by a porous polyelectrolyte through which the waste water flows.

Abstract: Electrically conductive polymers derived from heterocyclic polycyclic monomers formed of at least two cycles of five condensed members, each cycle containing one heteroatom, as well as a method of electrochemical polymerization by anodic oxidation of these monomers. These polymers may become part of composite electroconductive material.

Abstract: Carbon losses are reduced in that an operative carbon anode is glued beneath a carbon core in an inert anode top. The operative anode carbon is almost completely consumed. The anode top is then cleaned and a new operative carbon is glued to its underside.

Abstract: An apparatus, used in operation of electrolytic cells, to balance the interface pressure between liquid electrolyte and gas within the pores of a vertically disposed gas electrode. An electrode is sectioned into a plurality of lateral, or horizontal, gas compartments, vertically superposed, along one face of the electrode. The opposite face of the electrode is exposed to the liquid electrolyte. Each lateral compartment is supplied with gas. Each lateral compartment is also connected, via a separate gas line, to the bottom of a separate vertical chamber in a weir system. Each chamber has a vertical height equal to the depth of its respective cell compartment beneath the surface of the liquid electrolyte. The top of each weir chamber is provided with an overflow weir. Further, the chambers are arranged so that the overflow weir of each chamber flows into the next chamber, in order of decreasing vertical height. Gas is allowed to escape each lateral electrode compartment into a weir chamber.

Abstract: In a bioelectrochemical process in which the electrons are transferred directly, without use of a mediator, such as a redox dye or cofactor, between an electrode and an electroactive biological material, such as an enzyme or a protein, in either direction, rapid electron transfer has previously been achieved between an electrode and the positively charged protein horse-heart cytochrome c by adding a surface-modifier such as 4,4'-bipyridyl or a derivative thereof.It has now been found possible to promote electron transfer to either a positively or a negatively charged protein using the same surface-modifier for either job, namely a compound of formula ##STR1## wherein: the pyridine ring shown is substituted in the 2-, 3- or 4-position by the (methylene)hydrazinecarbothioamide group shown;R.sup.1 represents hydrogen atom(s) or one or two methyl or ethyl groups in the 2-,3- or 4-position (when the said position is not substituted by the (methylene)hydrazinecarbothioamide group shown);R.sup.

Abstract: A flow-through electrochemical cell for sequentially oxidizing and reducing an aryl compound. The cell includes a cell body forming a compartment to hold an aqueous electrolyte solution, a porous anodic electrode, and a porous cathodic electrode. The anodic electrode includes a first porous layer of a hydrophobic material, a second porous layer with an oxidation catalyst dispersed therein, and a current collector in electrical contact with the second layer. The cathodic electrode comprises a block of a porous, electrically-conductive material impregnated with lead particles. The cell is particularly useful for the preparation of aryl hydroquinones at very high current efficiencies, high current densities, and low voltages.

Abstract: Carbon dioxide reactions occurring during carbon electrode use in the production of aluminum can be decreased by contacting the outer surface of the calcined coke with elemental sulfur prior to the formation of the coke into an electrode.

Abstract: The invention relates to a cathode rod permitting extraction of the current from a cell for the production of aluminum by electrolysis according to the Hall-Heroult process, which is sealed in at least one groove which is open at the base of each of the carbonated blocks 1 forming the cathode of the electrolysis cell.According to the invention, the cathode rod 2 is extended by a metal sole 5 in electrical contact with the base of the carbonated blocks 1 over at least 20% of the total surface area of this base. The sole 5 is constituted by a metal sheet which is at least 4 mm thick and preferably at least 10 mm thick and is soldered to the cathode rod 2 before the carbonated block 1 is positioned in the cell.To prevent infiltration of electrolyte into the subcathode space, the lower face of the sole 5 is placed in a superimposed relationship and in electrical contact with a thick, continuous metal screen 26 arranged at the top of the thermally insulating lining.

Abstract: An anode of about 98% carbon, 2% silica gel and less than 1% inert binders is mounted on a layer spread on a metal surface.

Abstract: An improved electrocatalytic gas diffusion electrode comprising an open pore carbon cloth carrying on one side a first uniform mixture of noble-metal-catalyzed carbon and a hydrophobic binder adhered within the cloth pores and to the yarns of the cloth to a depth less than the thickness of the cloth, and a second uniform mixture of non-catalytic carbon and a hydrophobic binder adhered to the remaining open pore portion on the other side of said cloth; and method of preparation.

Abstract: An improved electrode assembly is disclosed for use in a cell for the production of metal by electrolytic reduction comprising a nonmetallic conductive electrode having a top surface and a central current carrying support shaft received in a central bore extending axially downward from the top surface. Conductive fin members extend radially from the central support shaft in the electrode, the fin members comprising a plurality of gate members extending radially from the central shaft adjacent a top surface of the electrode and wing members extending from the gate members downwardly into the electrode from the top surface. The gate members are provided with tapered surfaces extending toward the center of the electrode whereby expansion of both the nonmetallic and the metallic portions of the electrode assembly will enhance the electrical contact between the wing members and the nonmetallic portions of the electrode to thereby further minimize the voltage drop in the electrode.

Abstract: Amorphous carbon is an electrocatalytically active material which is useful as an electrode component in electrochemical cells.

Abstract: A fluroinated graphite having the formula (C.sub.x F).sub.n wherein x is a numerical value of about 2.0 to about 5.5 and n refers to an indefinite number of the recurring (C.sub.x F) unit and having a crystalline structure exhibiting a peak at about 13.7.degree. to about 15.0.degree. in terms of an angle of 2.theta. corresponding to the diffraction at the (001) plane in the X-ray diffraction pattern, a peak in the vicinity of 685.3 eV due to the F.sub.ls and two peaks in the vicinity of 287.5 eV and 284.3 eV due to the C.sub.ls in the spectrum of electron spectroscopy of chemical analysis, two peaks in the vicinity of 1100 cm.sup.-1 and 1240 cm.sup.-1 in the IR spectrum, and an electric conductivity of at least about 10.sup.-8 .OMEGA..sup.-1 cm.sup.-1, and being thermlly stable in air up to 200.degree. C.

Abstract: Gas depolarized cathodes having hydrophobic barrier layers for circulation electrolyte electrochemical cells; methods of making said cathodes; and methods of electrolyzing solutions of halide containing compounds using said electrodes. Typically, in electrochemical cells cathodes are oriented vertically resulting in significant electrolyte pressure against the cathode. The barrier layer comprising fluorocarbon polymer and carbon results in substantially no electrolyte leakage through the cathode when the electrolyte pressure is up to three pounds per square inch above ambient.

Abstract: Improved activated carbon electrodes are disclosed, which electrodes have increased charge storage capacity. Such improved electrodes are incorporated into energy storage devices such as electrical double layer capacitors. The improved charge storage capacity is due to the adsorption of polyoxometalate compounds into the activated carbon, which compounds are capable of reversible redox reactions and so provide a secondary charge storage mechanism without decreasing the charge storage ability of the activated carbon.