Abstract: Described are preferred multilayer, thin-film electrodes (11) that have improved resistance to flaking or cracking under conditions of operation. Also described are electrolytic cells (17) incorporating such electrodes (11), and methods for selecting electrode materials to facilitate reaction rates, energy production, and/or to shift the average mass number of transmuted products to lighter or heavier values. Preferred electrodes (11) have a plurality of thin-film conductive layers (14) supported on generally concave surfaces (13).

Abstract: Electrode at least comprising an electroconductive support of a titanium-palladium alloy, titanium, tantalum or compounds or alloys of titanium or of tantalum, an electrochemically active coating and an interlayer between the support and the electrochemically active coating, wherein the interlayer consists of titanium carbide and/or titanium boride and is applied to the support by flame or plasma spraying. Process for producing these electrodes and their use in an electrochemical cell for producing chlorine or chromic acid.

Abstract: An electrode with large active surface area is made by winding a Ti-fiber tow around a rectangular Ti-plate, and an electrocatalytic coating of three layers is applied. A precoat comprising a mixture of iridium dioxide and tantalum pentoxide is applied first, using a solution of the corresponding chloride salts in hydrochloric acid with some nitric acid added to inhibit corrosion of the metal. A sealing coat is then applied, comprising tin dioxide doped with antimony, in order to improve adhesion of the final oxide coat to the precoat. The third and final coat comprises particles of titanium dioxide doped with niobium in the +4 oxidation cemented with titanium dioxide that is doped with antimony. Anodes of this description are preferably assembled together with corrosion resistant cathodes in an alternating sequence, with a plastic coated fiber glass mesh placed between the anodes and cathodes to prevent short circuiting.

Abstract: The invention relates to a method for preparing a substantially lead-free turbulence promoting electrode, wherein an amount of turbulence promoting particles having a particle size from about 30 to about 2000 &mgr;m are contacted with at least one electrode and brought to adhere thereto, such that from about 5 to about 50% of the projected electrode surface area is covered with the particles. The invention also relates to a turbulence promoting electrode obtainable by the method and an electrode comprising turbulence promoting elevated parts arranged on at least one surface of the electrode. The height of the elevated parts is from about 30 to about 2000 &mgr;m. The invention further relates to the use of the electrode in an electrolytic cell for the production of alkali metal chlorate and alkali metal hydroxide.

Abstract: An electrolytic cell producing sodium chlorate uses an electrode, specifically an anode, having a surface or coating or treatment of a mixed metal oxide having ruthenium oxide as an electrocatalyst, a precious metal of the platinum group or its oxide as a stability enhancer, antimony oxide as an oxygen suppressant and a titanium oxide binder. The electrocatalytic coating is about 21 mole percent ruthenium oxide, about 2 mole percent iridium oxide, about 4 mole percent antimony oxide and the balance is titanium oxide. The coating is characterized by high durability and low oxygen content in an off-gas.

Abstract: A method to electrolytically polymerize aromatic hydrocarbons and oxidize cyclopentane structures within the hydrocarbons into cyclopentanone structures is disclosed including a method to electrolyse fluorene in the presence of an ester to produce poly(9-fluorenone). A method to electrolytically oxidize polymers having cyclopentane structures to polymers having cycloppentanone structures is also disclosed including a method to electrolyze poly(fluorene) to produce poly(9-fluorenone). In addition, a method to chemically oxidize polymers containing cyclopentane structures into polymers containing cyclopentanone structures is disclosed, including a method to oxidize poly(fluorene), with a chemically prepared oxidizing agent, to produce poly(9-fluorenone).

Abstract: An electrodeionization apparatus and method of use includes an expanded conductive mesh electrode. The expanded conductive mesh electrode may be formed from any conductive material that is dimensionally stable and may be coated with conductive coating suitable for use in anode or cathode service. The expanded conductive mesh electrodes are formed by slitting a sheet of metal and pulling its sides in a direction perpendicular to the slits. The fabricated mesh may be flattened after stretching. The expanded conductive mesh electrodes typically have a diamond-shaped pattern of any size that provides support for an adjacent ion-permeable membrane while allowing an electrode or fluid stream to flow through. The mesh size typically has a long-wise dimension and a short-wise dimension. The conductive mesh electrode may also be placed against an endblock having fluid channels. These channels may be serpentine or parallel channels, which allow fluid flow to wash away any accumulation.

Abstract: The present invention is directed to methods for applying a protective layer (42) to the cathode (40) of an electrolysis cell (10), where the cell also contains inert anodes (50) and the protective layer (42) can comprise a plurality of layers (70, 72, 74) with an inner layer (70) of TiB2 being preferred, and the protective layer (42) protects the cathode (40)from hot gases (64) used to pre-heat the cell (10).

Abstract: A cathode comprising an electrically conductive substrate made of titanium, nickel, tantalum, zirconium, niobium, iron or alloys thereof, coated with an intermediate layer of oxides of titanium and of a precious metal, and with an outer layer comprising metal oxides of titanium, zirconium and a precious metal, can be used for the electrolysis of solutions, in particular for the electrolysis of aqueous solutions of alkali metal chlorides.

Abstract: An improved electrode for use in generating an electrical field in a saline solution is provided. In particular, a continuous crystalline metal nitride coated electrode is provided for use in a variety of saline solution applications, such as in an electrophoresis device for separating proteins or nucleic acids or an electroporation apparatus for the encapsulation of biologically-active substances in various cell populations. A method and apparatus are provided for the encapsulation of biologically-active substances in red blood cells, characterized by an optionally automated, continuous-flow, self-contained electroporation system which allows withdrawal of blood from a patient, separation of red blood cells, encapsulation of a biologically-active substances in the cells, and optional recombination of blood plasma and the modified red blood cells thereby producing blood with modified biological characteristics.

Abstract: A method of treating a carbonaceous cell component of an electrolyte cell for the production of aluminum, to impart protection against deterioration during operation of the cell. A liquid suspension of a refractory material dispersed in a lignosulfonate binder solution is prepared and applied as a protective coating to the surface of carbonaceous cell components and allowed to dry.

Abstract: Disclosed is A flow-through electrochemical reactor comprising a body having an internal chamber, and an inlet port and an outlet port in communication with said internal chamber to permit flow of wastewater therethrough, at least one porous anode arranged in said internal chamber such that the wastewater flowing between said inlet port and said outlet port flows through the pores of said at least one porous anode, said at least one porous anode having activity for the destruction of a target substance, and at least one cathode disposed in the internal chamber to permit an electric current to be established between said at least one cathode and said at least one anode, said electric current reducing the concentration of said target substance in the wastewater flowing through the chamber.

Abstract: A method of preparing carbonaceous blocks or bodies for use in a cathode in an electrolytic cell for producing aluminum wherein the cell contains an electrolyte and has molten aluminum contacting the cathode, the cathode having improved wettability with molten aluminum. The method comprises the steps of providing a carbonaceous block and a boron oxide containing melt. The carbonaceous block is immersed in the melt and pressure is applied to the melt to impregnate the melt into pores in the block. Thereafter, the carbonaceous block is withdrawn from the melt, the block having boron oxide containing melt intruded into pores therein, the boron oxide capable of reacting with a source of titanium or zirconium or like metal to form titanium or zirconium diboride during heatup or operation of said cell.

Abstract: The invention concerns a bipolar electrode with a semiconductor coating and a cathode, as well as a procedure for the electrolytic dissociation of water, especially for the recovery of hydrogen. The body material of the cathode and/or the anode in this procedure is preferably comprised of titanium or platinum coated titanium, whereby, on the anode an additional semiconductor coating is applied, said coating being preferentially titanium dioxide (TiO2), which is dosed with iron (Fe). The advantage of the bipolar electrode is that an increased volume of hydrogen per time unit can be recovered and further, with these bipolar electrodes a simple procedure at ambient surroundings and conditions is achieved without expensive equipment for hydrogen production. In addition the anode of the invented bipolar electrodes can also be radiated with UV-radiation for the purpose of an increase in efficiency.

Abstract: A non-carbon, metal-based slow-consumable anode of a cell for the electrowinning of aluminium self-forms during normal electrolysis an electrochemically-active oxide-based surface layer (20). The rate of formation (35) of the layer (20) is substantially equal to its rate of dissolution (30) at the surface layer/electrolyte interface (25) thereby maintaining its thickness substantially constant, forming a limited barrier controlling the oxidation rate (35). The anode (10) usually comprises an alloy of iron with at least one of nickel, copper, cobalt or zinc which during use forms an oxide surface layer (20) mainly containing ferrite.

Abstract: A cermet anode of an electrolytic cell is protected from thermal shock during cell start-up by coating an outer surface portion of the anode with a coating composition comprising carbon or aluminum or a mixture thereof. A particularly preferred coating composition includes an aluminum underlayer adjacent the outer surface portion of the anode, and a carbon overlayer overlying the underlayer. A support structure assembly supporting the cermet anode includes a high alumina ceramic material. In a preferred embodiment, the high alumina ceramic material is protected from thermal shock and corrosion by the coating composition of the invention.

Abstract: A non-carbon metal-based anode of a cell for the electrowinning of aluminium comprising an electrically conductive metal substrate resistant to high temperature, the surface of which becomes passive and substantially inert to the electrolyte, and a coating adherent to the metal substrate making the surface of the anode electrochemically active for the oxidation of oxygen ions present at the electrolyte interface. The substrate metal may be selected from nickel, cobalt, chromium, molybdenum, tantalum and the Lanthanide series. The active constituents of the coating are for example oxides such as spinels or perovskites, oxyfluorides, phosphides or carbides, in particular ferrites. The active constituents may be coated onto the substrate from a slurry or suspension containing colloidal material and the electrochemically active material.

Abstract: Carbon-containing components of cells for the production of aluminium by the electrolysis of alumina dissolved in a cryolite-based molten electrolyte are protected from attack by liquid and/or gaseous components of the electrolyte in the form of elements, ions or compounds, by a refractory boride coating applied from a slurry composed of pre-formed particulate refractory boride in a colloidal carrier which is dried and heated to consolidate the coating.

Abstract: A cell for the electrowinning of aluminium comprising one or more anodes, each having a metal-based anode substrate, comprising a metal core covered with an metal layer, an oxygen barrier layer, one or more intermediate layers and an iron layer. The anode substrate is covered with an electrochemically active iron oxide-based outside layer, particularly a hematite-based layer, which remains dimensionally stable during operation in a cell by maintaining in the electrolyte a sufficient concentration of iron species. The cell operating temperature is sufficiently low so the required concentration of iron species in the electrolyte is limited by the reduced solubility of iron species in the electrolyte at the operating temperature, limiting the contamination of the product aluminium by iron to an acceptable level. The iron oxide-based layer is an applied coating or an oxidised surface of a substrate, the surface of which contains iron.

Abstract: A non-carbon, metal-based, high temperature resistant, electrically conductive and electrochemically active anode of an aluminum production cell has a metal-based substrate having an adherent coating applied prior to its immersion into the electrolyte and start up of the electrolysis. The coating is obtainable from one or more layers applied from: a liquid solution, a dispersion or suspension in a liquid or a paste, a pasty or non-pasty slurry, and combinations thereof with or without one or more further applied layers, with or without heat treatment between two consecutively applied layers when at least two layers are applied.

Abstract: Method and cell component for the electrowinning of aluminum by the electrolysis of alumina dissolved in a molten fluoride electrolyte comprises a porous micropyretic reaction product of nickel, aluminum, iron, copper and at least one additive element selected from silicon, tin zinc, vanadium, indium, hafnium, tungsten, elements from the lanthanide series starting from praesodymium, and misch metal. The micropyretic reaction product contains metallic and intermetallic phases, with a composite oxide surface produced in-situ by anodic polarization of the porous micropyretic reaction product in a molten fluoride electrolyte containing dissolved alumina, or by high temperature treatment in an oxidizing gas. The composite oxide surface usually comprises an iron-rich relatively dense outer portion and an aluminate-rich relatively porous inner portion.

Abstract: A cell for the electrowinning of aluminum comprises at least one non-carbon metal-based anode (10) having an electrically conductive metallic structure (12, 13, 15) which is suspended substantially parallel to a facing cathode (20, 21, 22). Such metallic structure (12, 13, 15) comprises a series of parallel horizontal anode members (15), each having an electrochemically active surface (16) on which during electrolysis oxygen is anodically evolved. The electrochemically active surfaces (16) are in a generally coplanar arrangement to form the active anode surface. The anode members are spaced apart from one another by inter-member gaps forming flow-through openings (17) for the circulation of electrolyte (30) driven by the escape of anodically-evolved oxygen. The electrolyte (30) may circulate upwardly and/or downwardly in the flow-through openings (17) and possibly around the anode structure (12, 13, 15).

Abstract: A compound electrode incorporating a lead substrate utilizes the lead as a support structure. This support structure provides a surface that engages a valve metal expanded metal mesh. The mesh member has a front and back surface with the back surface facing the lead support structure. At least the front surface of the mesh member is an active surface. Securing of the mesh member to the lead support structure in electrical connection permits the lead support structure to serve as a current distributor for the mesh member. The mesh member may engage the surface of the lead support structure by pressing or rolling the mesh onto the lead. Other engagement means can include the use of fasteners, or welding and the like. The resulting structure can be particularly useful as an electrode assembly for use in an electrolytic cell that serves for the electrowinning of a metal.

Abstract: The invention relates to a specific cathode comprising a substrate made of an element chosen from the group formed by titanium, nickel, tantalum, zirconium, niobium and alloys thereof, the said substrate being coated with an interlayer of a mixed oxide based on titanium and on ruthenium and with an external layer of metal oxides comprising titanium, zirconium and ruthenium. The subject of the invention is also its manufacturing process and its applications in electrolysis.

Abstract: The invention concerns a bipolar electrode with a semiconductor coating and a cathode, as well as a procedure for the electrolytic dissociation of water, especially for the recovery of hydrogen. The body material of the cathode and/or the anode in this procedure is preferably comprised of titanium or platinum coated titanium, whereby, on the anode an additional semiconductor coating is applied, said coating being preferentially titanium dioxide (TiO2), which is dosed with iron (Fe). The advantage of the bipolar electrode is that an increased volume of hydrogen per time unit can be recovered and further, with these bipolar electrodes a simple procedure at ambient surroundings and conditions is achieved without expensive equipment for hydrogen production. In addition the anode of the invented bipolar electrodes can also be radiated with UV-radiation for the purpose of an increase in efficiency.

Abstract: The invention is relative to an electrode for gas evolution in electrolytic and electrometallurgical industrial applications, made of a metal substrate having a surface morphology characterized by a combination of micro-roughness and macro-roughness which favors high adherence of a superficial catalytic layer in order to prevent detachment of the same and passivation of the substrate even under critical operating conditions.

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 treating a carbonaceous cell component of an electrolyte cell for the production of aluminum, to impart protection against deterioration during operation of the cell. A liquid suspension of a refractory material dispersed in a lignosulfonate binder solution is prepared and applied as a protective coating to the surface of carbonaceous cell components and allowed to dry.

Abstract: An anode of a cell for the electrowinning of aluminum comprises an iron-nickel alloy body or layer whose surface is oxidized to form a coherent and adherent outer iron oxide-based layer, in particular hematite, the surface of which is electrochemically active for the oxidation of oxygen ions and which reduces diffusion of oxygen from the electrochemically active surface into the iron-nickel alloy body or layer. The anode may be kept dimensionally stable during cell operation by maintaining a sufficient amount of dissolved alumina and iron species in the electrolyte to prevent dissolution of the outer oxide layer of the or each anode and by reducing the electrolyte operating temperature to limit dissolution of iron and by reducing the electrolyte operating temperature to limit dissolution of iron species in the electrolyte.

Abstract: A non-carbon, metal based slow-consumable anode of a cell for the electrowinning of aluminum self-forms during normal electrolysis an electrochemically-active oxide-based surface layer (20). The rate of formation (35) of the layer (20) is substantially equal to its rate of dissolution (30) at the surface layer/electrolyte interface (25) thereby maintaining its thickness substantially constant, forming a limited barrier controlling the oxidation rate (35). The anode (10) usually comprises an alloy or iron at least one of nickel, copper, cobalt or zinc which during use forms an oxide surface layer (20) mainly containing ferrite.

Abstract: An electrode for use in an electrochemical machining process comprising an outer metal skin of corrosion resistant material, an inner core of conductive material, and an insulating coating disposed on an external surface of the outer metal skin. The external surface is partially coated with the insulating coating so as to define a pattern of raised areas to be formed on an internal surface of a predrilled hole in a workpiece.

Abstract: A process of producing multi-layer cathode structures. In one aspect, the process comprises providing a carbonaceous cathode substrate, and forming at least one layer of a metal boride-containing composite refractory material over the substrate, wherein the surface of the carbonaceous substrate to be coated is roughened prior to the formation of the layer overlying the said surface. The roughening of the surfaces reduces the tendency of the layers to separate in high temperature operating conditions. In another aspect, the process comprises providing a carbonaceous cathode substrate, and forming at least two coating layers of a metal boride-containing composite refractory material successively over the substrate, wherein the content of metal boride in the coating layers increases progressively as the distance of the layer from the substrate increases.

Abstract: An electrode adapted for chromium plating from trivalent chromium baths which comprises a conductive base, an electrode material layer comprising iridium oxide formed thereon, and a porous layer formed on the surface of the electrode material layer. The porous can comprise an oxide containing at least one element selected from the group consisting of silicon, molybdenum, titanium, tantalum, zirconium, and tungsten. Use of this electrode for chromium plating reduces the oxidation of trivalent chromium into hexavalent chromium.

Abstract: A non-carbon, metal-based slow-consumable anode of a cell for the electrowinning of aluminium self-forms during normal electrolysis an electrochemically-active oxide-based surface layer (20). The rate of formation (35) of the layer (20) is substantially equal to its rate of dissolution (30) at the surface layer/electrolyte interface (25) thereby maintaining its thickness substantially constant, forming a limited barrier controlling the oxidation rate (35). The anode (10) usually comprises an alloy of iron with at least one of nickel, copper, cobalt or zinc which during use forms an oxide surface layer (20) mainly containing ferrite.

Abstract: An electrolyzing electrode which is for electrolyzing a metal electrolytic solution, shows a long lifetime in use as an ordinary anode and has sufficient durability even when in a poor potential region, and a process for the production thereof. The electrolyzing electrode of the present invention has an undercoating layer which is formed of platinum metal and tantalum oxide and contains, as metals, 1 to 20 at % of platinum and 80 to 99 at % of tantalum, on an electrically conductive electrode substrate, has an intermediate layer which is formed of iridium oxide and tantalum oxide and contains, as metals, 70 to 99.9 at % of iridium and 0.1 to 30 at % of tantalum, on the undercoating layer, and further has an overcoating layer which is formed of platinum metal and iridium oxide and contains, as metals, 60 to 99.9 at % of platinum and 0.1 to 40 at % of iridium, on the intermediate layer.

Abstract: An electrolytic cell comprised of a tank for holding electrolytic solution, and a drum rotatable about a horizontal axis having a non-conductive cylindrical outer surface disposed within the tank, and a plurality of elongated, like anodes arranged about the outer surface of the drum. The anodes together form a generally continuous cylindrical surface spaced from, and generally conforming to, the outer surface of the drum. Each of the anodes has at least one end projecting through the tank. A plurality of power sources is provided together with connection means for connecting groups of one or more of the projecting ends of the anodes to each power source.

Abstract: The present invention provides an improved anode formulation and an improved method of manufacture. More specifically, the invention provides a tri-layer anode having an improved service life when used, for example, for steel strip electrogalvinizing. In one embodiment of the invention, the anode is comprised of a titanium substrate which is roughened and heat treated and subsequently coated with a first coating of iridium oxide/tantalum oxide. After the anode is heat treated, it is next coated, preferably by an electrodeposition process with a second coating of platinum. Finally, the anode is coated with a third coating of iridium oxide/tantalum oxide and subsequently heat treated.

Abstract: An electrode for deionization of water is made of a continuous activated carbon structure. The activated carbon is derived from a synthetic carbon precursor. The structure has openings, inlet and outlet ends such that water entering the inlet end passes through the openings and exits through the outlet end, a conductive coating on at least part of the outer surface of the structure, and a metal wire in contact with the structure. A deionization system is made up of the electrodes in series so that the outlet end of one electrode is next to the inlet end of the nearest downstream electrode. The metal wire of each electrode is connected to a power source to deliver the opposite charge as the charge delivered to its neighboring electrodes. Each of the electrodes is fixedly attached to and sealed within a housing with an air and moisture-tight seal. Openings in the housing between the electrodes, allow air to be removed before use.

Abstract: Peroxydisulfuric acid and salts thereof are produced electrochemically from an aqueous acid sulfate solution in a cascading series of bipolar electrolytic cells having a cell body frames of polyvinyl chloride which are bonded with a vinyl ester polymer. An aqueous solution of peroxydisulfuric acid and salts thereof are withdrawn from the anode compartment of the last cell in the series, and metal impurities are removed by treatment with an ion exchange resin. Hydrogen peroxide is produced by hydrolyzing persulfuric acid and salts thereof. The sulfuric acid produced is recycled to the first cell in the series of cascading electrolytic cells.

Abstract: Metal nitride, carbonitride, and oxycarbonitride powder with high surface area (up to 150 m2/g) is prepared by using sol-gel process. The metal organic precursor, alkoxides or amides, is synthesized firstly. The metal organic precursor is modified by using unhydrolyzable organic ligands or templates. A wet gel is formed then by hydrolysis and condensation process. The solvent in the wet gel is then be removed supercritically to form porous amorphous hydroxide. This porous hydroxide materials is sintered to 725° C. under the ammonia flow and porous nitride powder is formed. The other way to obtain high surface area nitride, carbonitride, and oxycarbonitride powder is to pyrolyze polymerized templated metal amides aerogel in an inert atmosphere. The electrochemical capacitors are prepared by using sol-gel prepared nitride, carbonitride, and oxycarbonitride powder. Two methods are used to assemble the capacitors.