Abstract:
A method of welding a ferritic stainless steel part to a carbon steel part is described. The method comprises arc welding (e.g. GTAW welding) the ferritic stainless steel part to the carbon steel part using a duplex stainless steel filler metal. Welded article made in this way is useful for industrial electrolyzers and particularly for corrosion resistant cathode and carrier plate assemblies in a sodium chlorate electrolyzer.
Abstract:
An electrochemical cell for causing a reaction that produces hydrogen, the electrochemical cell comprising: a first electrode comprising: at least one layered electrocatalyst formed of at least one active metal layer deposited on a carbon support, wherein the at least one active metal layer is active to a target species; a second electrode comprising a conductor; a basic electrolyte; ammonia, ethanol, or combinations thereof; and electrical current in communication with the first electrode. An fuel cell utilizing ammonia, ethanol, or combinations thereof, comprising: a housing; an anode disposed within the housing, the anode comprising at least one layered electrocatalyst, wherein the at least one layered electrocatalyst comprises at least one active metal layer and at least one second metal layer deposited on a carbon support; a basic electrolyte disposed adjacent the anode; a cathode disposed adjacent the basic electrolyte, wherein the cathode comprises a conductor; and an oxidant in communication with the cathode for connecting with a power conditioner, a load, or combinations thereof, wherein the power conditioner, the load, or combinations thereof is in communication with the anode, which oxidizes the ammonia, ethanol, or combinations thereof, causing the fuel cell to form an electric current. An electrochemical method for providing hydrogen using ammonia, ethanol, or combinations thereof, comprising: forming an anode comprising a layered electrocatalyst, the layered electrocatalyst comprising at least one active metal layer deposited on a carbon support; providing a cathode comprising a conductor; disposing a basic electrolyte between the anode and the cathode; disposing a fuel within the basic electrolyte; and applying a current to the anode causing the oxidation of the fuel, forming hydrogen at the cathode. A layered electrocatalyst for oxidizing ammonia, ethanol, or combinations thereof, comprising: a carbon support integrated with a conductive metal; at least one first metal plating layer at least partially deposited on the carbon support, wherein the at least one first metal plating layer is active to OH adsorption and inactive to a target species, and wherein the at least one first metal plating layer has a thickness ranging from 10 nanometers to 10 microns; and at least one second metal plating layer at least partially deposited on the at least one first metal plating layer, wherein the at least one second metal plating layer is active to the target species, and wherein the at least one second metal plating layer has a thickness ranging from 10 nanometers to 10 microns, forming a layered electrocatalyst.
Abstract:
A conductive diamond electrode including an electrode substrate comprising a material selected from the group consisting of a valve metal and an alloy based on the valve metal, at least a surface of the metal or alloy having been subjected to plasticization processing, or heat treatment in vacuum or inert atmosphere; and a conductive diamond film formed on the plasticization processed surface of the electrode substrate. When the electrode substrate is subjected to plasticization processing and heat treatment, peeling resistance of the conductive diamond film is improved, thereby an electrode life is prolonged.
Abstract:
A porous, high surface area electrode comprising a fine fibrous conductive substrate having a density less than about 50 % and a specific surface area to volume ratio of greater than about 30 cm2/cm3. The individual fibers of the substrate have a length to diameter aspect ratio greater than 1000 : 1. An electrocatalyst covers at least a portion of the substrate. A current distributor is electrically connected to the coated substrate. The method of fabricating the electrode includes fabricating a fine fibrous conductive substrate, preparing the surface of the substrate for receiving an electrocatalyst covering thereon, preparing the electrocatalyst for application to the substrate and applying the electrocatalyst to the substrate. Optionally, the electrode may be further treated to promote adhesion of the electrocatalyst to the substrate or to form an intermetallic or alloy with the substrate.
Abstract:
A self-supporting reticulate of titanium hydride (TiH 2 ) is formed by slurry-coating an open cell organic synthetic resinous material, or other pore-former, and eliminating the carbon-containing components of binder and/or solvent, viscosity modifiers, thickening agents, and the like at a temperature below about 400°C. In an analogous manner, an inorganic refractory material open cell substrate or other pore-former substrate may be slurry-coated and converted to a TiH 2 reticulate in which the substrate is coated with TiH 2 to yield a supported TiH 2 reticulate. Either the self-supporting TiH 2 reticulate, or the supported one, free of carbonaceous material, may be sintered to yield an essentially pure Ti (metal) reticulate which is essentially free of titanium carbide. Ti reticulates so formed are coated with Pt group metal oxides and used as anodes in chloralkali cells.
Abstract:
The invention relates to vertical or inclined electrodes of an electrolyzer for electrolytically producing aluminum from aluminum oxide. An electrode contains an electrode base and a surface coating based on refractory ceramics. According to a first variant of the invention, the electrode base is made of a composite material containing between 5% and 90% by mass of refractory ceramics, and of at least one metal having a melting temperature exceeding 1000°C, which forms refractory intermetallic compounds upon interaction with aluminum, and/or containing at least one alloy of such a metal. According to a second variant of the invention, the electrode base is made of a metal alloy, for example structural steel or another alloy, and the surface of the electrode base has applied thereto an intermediary layer consisting of a composite material having the composition described above.
Abstract:
A novel modified anode/electrolyte structure for a solid oxide electrochemical cell is an assembly comprising (a) an anode consisting of a backbone of electronically conductive perovskite oxides selected from the group of doped strontium titanates and mixtures thereof, (b) a scandia and yttria-stabilised zirconium oxide electrolyte and (c) a metallic and/or a ceramic electrocatalyst in the shape of interlayers incorporated in the interface between the anode and the electrolyte. This assembly is first sintered at a given temperature and then at a lower temperature in reducing gas mixtures. These heat treatments resulted in a distribution of the metallic and/or ceramic interlayers in the electrolyte/anode backbone junction taking place. The structure is prepared by (a) depositing a ceramic interlayer onto one side of the electrolyte, (b) optionally applying a metallic interlayer thereon, (c) repeating steps (a) and (b), (d) applying a layer of the selected anode backbone onto the electrolyte with applied interlayers, (e) sintering the raw assembly and (f) infiltrating the electrocatalyst precursor into the sintered assembly and heat treating the assembly to incorporate additional electrocatalyst into the anode backbone.
Abstract:
The invention relates to a gas-diffusion electrode provided with a sintered and cast gas-diffusion layer having a high elastic modulus. The electrode is useful as hydrogen-consuming anode or oxygen-consuming cathode of depolarised electrolytic cells such as electrowinning, chlor-alkali or electrodialysis cells.
Abstract:
A hydrogen-evolution electrode having a coating containing an oxide of at least one metal selected from the group consisting of nickel, cobalt and silver has been found to exhibit extremely low hydrogen overvoltage and to have not only high catalytic activity but also high durability. When the electrode having a reduced coating fabricated by reduction of said coating containing the oxide of said at least one metal, the resulting electrode exhibits extremely low hydrogen overvoltage even if the proportion of the oxide or oxides in the coating is small. Further, the electrode having a composite coating in which, beside the oxide of said at least one metal, at least one metal or oxide thereof which metal has a valency smaller than that of the first-mentioned at least one metal is additionally present in said coating, the electrode exhibits further extremely low hydrogen overvoltage, even if the proportion of oxide in the coating is large.