Anode with an electrodeposited metal interlayer

Abstract

A method for facilitating the electrolytic deposition of chromium onto a metal substrate from an electrolyte solution containing an ionic form of chromium and one or more organic additives in an electrodeposition vessel by applying an electric current through the electrolyte from an anode to the metal substrate to deposit chromium on the metal substrate, the method comprising the steps of providing an anode comprising a core made of a valve metal, an intermediate layer disposed on the core and made of one of a titanium-tantalum alloy or a titanium-palladium alloy, and a layer of catalytic material disposed on the intermediate layer.

Description

[Technical Field]

[0001] The main aspects relate generally to electrode coatings, and more specifically to two-layer electrode coatings, their preparation methods, and their use. [Overview of the Initiative] [Problems that the invention aims to solve]

[0002] According to one embodiment, a method is provided for electrolytically depositing chromium onto a metal substrate by applying an electric current from an anode to the metal substrate through an electrolyte, the electrolyte containing chromium in ionic form and one or more organic additives in an electrodeposition container. The method comprises the step of preparing the anode, wherein the anode includes a core made of valve metal, an intermediate layer disposed on the core and made of or consisting of one of a titanium-tantalum alloy or a titanium-palladium alloy, and a catalyst material layer disposed on the intermediate layer.

[0003] In some embodiments, the anode is prepared to have a core made of titanium.

[0004] In some embodiments, the anode is prepared having the catalyst material layer composed of a mixed metal oxide of iridium and tantalum.

[0005] In some embodiments, the anode is prepared having a catalyst material layer composed of one or more of platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide.

[0006] In some embodiments, the anode is 3 g / m 2 ~70g / m 2 iridium, for example, about 10g / m³ 2It is prepared as having the catalyst material layer containing iridium.

[0007] In some embodiments, the anode is provided as having the intermediate layer containing titanium and tantalum in a weight ratio ranging from 30:70 to 70:30.

[0008] In some embodiments, the anode is prepared as having the catalyst material layer composed of iridium and tantalum in a mass ratio ranging from 9:1 to 2:1.

[0009] In some embodiments, one or more organic additives contain either formic acid or sulfonic acid.

[0010] In some embodiments, the step of preparing the anode is such that, without the anode being damaged, the anode has a structure and composition configured to allow more charge to pass through at mA h per anode area than an anode having no such intermediate layer or an intermediate layer formed of either titanium oxide or tantalum oxide. 2 The step of preparing the anode includes preparing the anode as having the structure and composition configured to allow more charge to pass through at mA h per anode area than an anode having no such intermediate layer or an intermediate layer formed of either titanium oxide or tantalum oxide.

[0011] In some embodiments, the step of preparing the anode includes preparing the anode as having the structure and composition configured to allow 50 mA h or more to pass through per m of anode area before the anode is damaged. 2 The step of preparing the anode includes preparing the anode as having the structure and composition configured to allow 50 mA h or more to pass through per m of anode area before the anode is damaged.

[0012] In some embodiments, the electrolytic solution has a pH of less than 0 to 4, 0 to 4, 1 to 4, or 2.5 to 3.5.

[0013] In another embodiment, a method is provided for electrolytically depositing a metal onto a conductive substrate by applying an electric current from an anode through the conductive substrate to the conductive substrate, thereby facilitating the electrolytic deposition of the metal from an electrolyte containing the ionic form of the metal and one or more organic additives within an electrodeposition container. The method comprises the step of preparing the anode, wherein the anode comprises a core made of titanium, an intermediate layer disposed on the core and composed of one of titanium-tantalum alloy, titanium grade 7, titanium grade 7H, titanium grade 11, titanium grade 16, titanium grade 16H, titanium grade 17, or titanium grade 19, and a catalyst material layer disposed on the intermediate layer and composed of one or more of platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide.

[0014] In some embodiments, the anode is prepared to have a core made of either titanium grade 1 or titanium grade 2.

[0015] In some embodiments, the electrolyte includes an aqueous solution containing one of chromium ions, tin ions, zinc ions, or copper ions.

[0016] In some embodiments, the electrolyte comprises an aqueous solution containing chromium ions, and is maintained under conditions in which the chromium ions are mainly present as Cr(III).

[0017] In some embodiments, the pH of the electrolyte is maintained between less than 0 and 4, 0 and 4, 1 and 4, or 2.5 and 3.5.

[0018] In some embodiments, the anode is prepared to have the catalyst, which is composed of one or more of platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide.

[0019] In some embodiments, the one or more organic additives include either formic acid or sulfonic acid.

[0020] In some embodiments, the step of preparing the anode is to prepare the anode area 1 m² before the anode is damaged. 2 The step includes preparing the anode having a structure and composition configured to allow more than 50 MAh per unit to pass through.

[0021] In some embodiments, the electrolyte comprises either sulfuric acid or sulfonic acid.

[0022] In another embodiment, a method is provided for facilitating the electrolytic deposition of a metal onto a substrate from an electrolyte containing an ionic form of the metal and one or more organic additives, by applying an electric current through the electrolyte from an anode, which is in electrical contact with the electrolyte in the electrodeposition container, to a cathode. The method comprises the step of preparing the anode, the anode comprising a substrate made of valve metal, an intermediate layer disposed on the substrate and made of a titanium-tantalum alloy, and a catalyst disposed on the intermediate layer.

[0023] In another embodiment, a method for electrodepositing chromium onto a substrate comprises the step of supplying the anode, which includes a metal substrate having a catalyst layer containing a mixed metal oxide of iridium, and an intermediate layer disposed between the substrate and the catalyst layer, wherein the intermediate layer contains an alloy of titanium and tantalum, or titanium and palladium.

[0024] In some embodiments, the anode is supplied having the catalyst layer which is a mixed metal oxide of iridium and tantalum.

[0025] In some embodiments, the anode is supplied having the intermediate layer which is substantially free of titanium or tantalum oxide.

[0026] In some embodiments, the anode is supplied having the metal substrate made of valve metal.

[0027] In some embodiments, the anode is supplied with approximately 5 to approximately 20 kA / m 2 It is supplied as having a structure and composition configured to allow passage.

[0028] In another embodiment, a method is provided for modifying a system for electrodepositing chromium onto a conductive substrate from an organic-containing electrolyte. The method comprises replacing the anode of the system with an anode comprising a core made of titanium, an intermediate layer disposed on the core and made of a titanium-tantalum alloy, and a catalyst disposed on the intermediate layer, comprising one or more of platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, tantalum, palladium, or tantalum oxide.

[0029] Various aspects of at least one embodiment are described below with reference to accompanying drawings, which are not intended to be drawn to scale. The drawings are included to illustrate and further understand the various aspects and embodiments, are incorporated into and form part of this specification, but are not intended to define the limits of this disclosure. Where reference numerals follow a drawing, a detailed description, or a technical feature of a claim, the reference numerals are used solely for the purpose of improving the clarity of the drawings and descriptions. In the drawings, identical or substantially identical components shown in different drawings are represented by similar numerals. For clarity, not all components are shown in all drawings. [Brief explanation of the drawing]

[0030] [Figure 1A] Figure 1A is a side view of an electrode according to one embodiment of the present disclosure. [Figure 1B] Figure 1B is a perspective view of an electrode according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic diagram of an electrochemical device according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0031] An electrode is a solid conductor through which electric current enters and exits an electrolytic cell or other medium. Electrodes can be used in any electrochemical process that requires a conductor. For example, electrodes can be used in electrogalvanizing, electroplating, electrotin plating, electroforming, electrolytic deposition (e.g., electrolytic deposition of metals such as copper, nickel, and zinc), and other electrochemical processes. Electrodes can be used in halogen generation processes such as the production of hypochlorite, chlorate, and chlor-alkali, or in chlorine organic synthesis processes. Electrodes can also be used in electrolytic chlorination systems and processes. In electrolytic chlorination systems and processes, sodium hypochlorite can be produced by the electrolysis of saline solution. For example, the OSEC® B-series on-site electrolytic chlorination system, available from Evoqua Water Technologies (Pittsburgh, Pennsylvania), produces sodium hypochlorite on-site on demand by electrolysis of saline solution.

[0032] The electrodes, associated electrodeposition systems, and electrolytes disclosed herein can be used, for example, for electroplating metals such as Cr, Sn, Cu, and Zn onto conductive substrates such as steel strips.

[0033] Electrodes can be used in electrolytic cells. An electrolytic cell is an electrochemical cell that can be used to overcome the positive free energy that causes involuntary reactions and to force a chemical reaction in a desired direction. An electrolytic cell converts electrical energy into chemical energy or produces chemical products through a chemical reaction.

[0034] The electrodes in an electrolytic cell are sometimes called the anode or cathode, depending on the direction of the current flowing through the cell. The anode is the electrode where electrons leave the cell and oxidation of ions occurs, while the cathode is the electrode where electrons enter the cell and reduction of ions occurs. Under these conditions, the direction of the current flowing through the cell is from the anode to the cathode. Each electrode can be either an anode or a cathode, depending on the process and the direction of the current flowing through the cell.

[0035] The design of an electrolytic cell and its electrodes may depend on one or more factors. These factors may include, for example, construction and operating costs, the desired product, electrical, chemical, and transport properties, electrode materials, shape, and surface properties, the pH of the system (e.g., electrolyte pH), the temperature of the system (e.g., electrolyte temperature), competing undesirable reactions, and undesirable by-products.

[0036] Depending on the electrochemical process, one or more process characteristics, such as the current density in the electrolytic cell, the system's pH (e.g., electrolyte pH), or the system's temperature (e.g., electrolyte temperature), can affect the effectiveness of the system and process, for example, the lifespan of the electrodes. For instance, exposure to one or more of high current density, low pH, or high temperature can reduce the lifespan of the electrodes. In some embodiments, exposure to one or more of high current density, low pH, or high temperature can cause electrode passivation.

[0037] Passivation is the inhibition of dissolution reactions caused by the formation of a non-dissolving film. Passivation of the anode and / or cathode can result in one or more of the following: loss of production capacity, increased power costs, and degradation of the anode and / or cathode quality. When titanium is used as the anode material, anode passivation is the growth of an insulating titanium dioxide layer in the anode coating and core, which increases the potential at the anode and causes anode deactivation. In some embodiments, exposure to one or more of the following: high current density, low pH, or high temperature can cause electrode wear. Electrode wear, or "electrode wear depletion," is the removal of material from the electrode. In some embodiments, exposure to one or more of the following: high current density, low pH, or high temperature can cause both electrode passivation and wear.

[0038] As mentioned above, electrolytic cells can contain electrolytes. Electrolytes are substances that, when dissolved in a polar solvent such as water, produce a conductive solution. This solution is electrically neutral. The dissolved electrolyte separates into cations and anions, which are uniformly dispersed in the solute. When an electric potential or voltage is applied to the electrolyte solution, cations are attracted to electron-rich electrodes, and anions are attracted to electron-deficient electrodes. The movement of anions and cations in opposite directions within the solution constitutes an electric current. Electrolytes are called strong electrolytes or weak electrolytes depending on the degree of solute dissociation. For example, if more than 50% of the solute dissociates into free ions, the electrolyte is strong. If a large percentage of the solute, for example less than 50%, does not dissociate, the electrolyte is weak.

[0039] In some embodiments, the electrodes may be exposed to an electrolyte having a low pH. For example, the electrolyte may be a strongly acidic electrolyte. In some embodiments, the strongly acidic electrolyte may be sulfuric acid or other acids, or may contain sulfuric acid or other acids.

[0040] In some embodiments, low pH may refer to an electrolyte having a pH lower than about 4 or lower than about 3. In some embodiments, low pH may refer to an electrolyte having a pH lower than about 2. In some embodiments, low pH may refer to an electrolyte having a pH lower than about 1. In some embodiments, low pH may refer to a pH lower than about 0.8. In some embodiments, low pH may refer to a pH lower than about 0.6. In some embodiments, low pH may refer to a pH lower than about 0.4. In some embodiments, low pH may refer to a pH lower than about 0.2.

[0041] In some embodiments, the electrode may be exposed to an electrolyte having a high temperature. The high temperature can be a temperature at which the cell voltage of the electrode undesirably decreases. The high temperature can be a temperature higher than about 50°C. In some embodiments, the high temperature is higher than about 55°C. In some embodiments, the high temperature is higher than about 60°C. In some embodiments, the high temperature is higher than about 65°C. In some embodiments, the high temperature is higher than about 70°C.

[0042] In some embodiments, the electrode may be exposed to a high current density. Current density is a measure of the density of current. It is defined as a vector representing the current per effective area of the electrode and is measured in amperes per square meter (A / m 2 2). A high current density can result in undesirable outcomes. For example, a high current density can potentially result in undesirable outcomes for one or more of the coating, electrode, electrolytic cell, and electrochemical device. The electrode has a finite positive resistance and dissipates power in the form of heat. The current density should be kept low enough to protect the electrode from passivation or depletion.

[0043] In some embodiments, a high current density is a current density that causes at least one of passivation and depletion of the electrode. In some embodiments, the high current density may be higher than about 0.5 kA / m 2 2. For example, the high current density may be about 1.0 kA / m2 It can be even higher. High current density is approximately 1.5 kA / m³. 2 It may be higher than that. In some embodiments, the high current density is about 2.0 kA / m². 2 It can be even higher. For example, a high current density is approximately 2.5 kA / m². 2 It may be higher. In some embodiments, the high current density is about 3.0 kA / m³. 2 It can be even higher. For example, a high current density is approximately 3.5 kA / m². 2 It may be higher. In some embodiments, the high current density is about 4.0 kA / m². 2 It can be even higher. For example, a high current density of approximately 4.5 kA / m² is acceptable. 2 It may be higher. In some embodiments, the high current density is about 5.0 kA / m². 2 This may also be the case. In some embodiments, the high current density is up to about 15 kA / m². 2 That's fine too.

[0044] Electrodes may be coated with two layers of coatings, the combination of which limits passivation and wear in specific electrochemical applications. The term "coating layer" may refer to one coating or two or more coatings. Using electrodes with two coatings can yield synergistic effects. These synergies can provide optimal (e.g., increased) performance of the electrode compared to the combined performance of an electrode with a first coating and an electrode with a second coating. For example, embodiments in which electrodes are used may have one or more properties such as low pH, high electrolyte temperature, and high current density.

[0045] Titanium-based anodes used in electrolytes containing various inorganic and organic components often suffer from accelerated corrosion of the titanium core, resulting in a shorter-than-expected lifespan. Corrosion of the electrode's titanium core can cause delamination of the electrode catalyst coating placed on the electrode core. By applying a protective layer on top of the titanium core (between the titanium core and the electrode catalyst coating), corrosion of the titanium core can be suppressed, extending the anode's lifespan. Titanium core electrodes with a protective coating can be used in any embodiment where corrosion of the titanium core is the primary factor causing the anode's lifespan to be shorter than expected or desired. The protective coating placed between the electrode core and the catalyst layer is referred to herein as the “interlayer.”

[0046] Electrolytes in various electrochemical applications may contain substances that can increase the corrosion of titanium cores in titanium-based anodes. These substances can be inorganic or organic. Corrosion of the titanium core can lead to premature failure of the anode. On the one hand, solutions have been described to reduce the corrosion rate of titanium cores in anodes with catalytic coatings consisting of noble metals and their oxides. These solutions are based on modifying the surface of the titanium core with various alloys to achieve better corrosion resistance.

[0047] Electrolytes used in metal plating often contain various organic additives that can lead to premature anode failure. Historically, this problem has been solved by adding a large amount of ir to the outer layer of the anode, but this has resulted in increased anode prices. This strategy is costly and has therefore not been widely adopted. By protecting the titanium core of the anode from corrosion, the ir load on the outer layer of the anode can be kept relatively low, making the anode price more attractive and extending its usable lifespan.

[0048] In one embodiment, an embodiment comprising the addition of a metal interlayer has been studied particularly for trivalent chromium plating ("ECL"), but anodes containing such a metal interlayer can also be used for plating other metals, such as tin, copper, and zinc. Trivalent chromium plating is a process of plating (also referred to herein as electrodeposition) a chromium / chromium oxide layer onto a metal strip, such as a steel strip, using an electrolyte solution containing trivalent chromium ("Cr(III)") instead of the more dangerous hexavalent chromium ("Cr(VI)"). In some embodiments, the electrolyte solution used for electrodeposition of Cr onto a conductive cathode comprises a Cr(III) compound and a chelating agent, and the anode includes a catalytic surface coating formed of one or more of platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide to reduce or remove the oxidation of Cr(III) ions to Cr(VI) ions.

[0049] The chelating agent may be an organic compound. The chelating agent may be a carboxylate salt, and may include formic acid or one of its salts, such as sodium formate (HCOONa) or other formate salts. The chelating agent can destabilize the Cr-containing hexaqua complex according to the following formula, where A- represents the ligand of the chelating agent. (1) Cr(H2O)6 3+ +A - ←→[Cr(H2O)5A] 2+ +H2O

[0050] Furthermore, the electrolyte may be maintained at an acidic pH, for example, <0 to 4, 0 to 4, 1 to 4, 2 to 3.5, 2.5 to 3.5, 2.5 to 3, or 2.8 to 3. An acidic pH can be maintained by including an acid, such as sulfuric acid, in the electrolyte. In processes for plating other metals, such as tin, sulfonic acid (e.g., methanesulfonic acid) may be used. The electrolyte may further contain salts that enhance conductivity, such as alkali metal sulfates, such as sodium sulfate (Na₂SO₄) or potassium sulfate (K₂SO₄). Sodium formate and alkali metal sulfates may be present at concentrations of about 1 M, but the embodiments and models disclosed herein are not limited to these concentrations. Furthermore, the electrolyte may become acidic even without the addition of acid due to a reaction at the anode during operation according to the following formula. (2) 2H2O → 4H + +O2(g)+4e -

[0051] Acidic electrolytes can suppress the oxidation of Cr(III) to Cr(VI) according to the following reaction. (3) Cr 3+ +4H2O ←→HCrO4 - +7H + +3e -

[0052] Cr can be added to electrolytes in the form of trivalent chromium salts such as chromium(III) sulfate, chromium(III) formate, chromium(III) oxalate, chromium(III) acetate, potassium chromium(III) oxalate, and / or chromium(III) nitrate.

[0053] One drawback of the chromium(III) electrodeposition process is the short lifespan of the anode. Improved anodes are desired to enhance the process's acceptability.

[0054] Furthermore, there are other applications that benefit from using a metal interlayer to improve corrosion resistance. These applications include, but are not limited to, the following: • Zinc, tin, and copper plating on steel plates • Common metal finishes, such as decorative plating on steel. ·Metal electrolysis ·(Organic) electrolytic synthesis ·Copper foil manufacturing • Copper printed circuit board manufacturing

[0055] The anode may include a substrate or core formed of titanium, optionally titanium grade 1 or titanium grade 2. The core may be coated with a material that helps prevent corrosion of the core, for example, a Ta / Ti layer in which Ti or Ta is present at a concentration of 40-60 wt%. Alternatively, the electrode core may be coated with a palladium-containing Ti alloy, for example, Ti grade 7 or Ti grade 11. Other Ti grades that may be used include Ti grades 7H, 16, 16H, 17, or 19. This material layer is referred to herein as HCrO4 according to formula (3) above. - Compounds like Cr 3+ An intermediate layer can be said to be a second material layer that is subsequently coated by a second material layer that acts as a catalyst surface coating that decomposes into water. As disclosed above, the catalyst surface coating may be one or more of platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide, or may contain these. In some embodiments, the catalyst coating layer is composed of a mixed metal oxide of iridium and tantalum, or consists of a mixed metal oxide of iridium and tantalum. The metal components of the catalyst coating layer may include 15-35 wt% Ta and 65-90 wt% Ir.

[0056] The electrodes, including the interlayers and catalytic coatings disclosed herein, in combination, exhibit high catalytic activity, stability, long lifespan, superior performance, reduced downtime due to less frequent electrode replacement, and cost-effectiveness. Ta / Ti (or titanium grade 7, titanium grade 7H, titanium grade 11, titanium grade 16, titanium grade 16H, titanium grade 17, or titanium grade 19) interlayers may provide a longer lifespan to the anode than other anodes formed from the same material but using Ta2O5 as the interlayer.

[0057] The intermediate layer may be applied directly to the electrode core, and the catalyst coating layer may be applied directly to the intermediate layer. The intermediate layer and the catalyst coating layer can reduce at least one of the following: electrode passivation, corrosion, peeling, and wear. In some embodiments, the intermediate film can reduce electrode passivation. In some embodiments, the catalyst coating layer can reduce electrode wear.

[0058] As used herein, a “two-coating layer electrode” refers to an electrode whose surface at least one of its surfaces is coated with a first coating made of a mixture to provide a first coating layer, and with a second coating that at least partially covers the first coating to provide a second coating layer. Herein, the first coating layer is referred to as the intermediate layer, and the second coating layer as the catalyst coating layer. The intermediate layer material(s) may be applied one or more times to achieve a desired material load. The catalyst coating layer material(s) may be applied one or more times to achieve a desired material load. At least one of the intermediate layer or the catalyst coating layer may be a mixture that reduces at least one of electrode passivation and wear. In some embodiments, the intermediate layer can reduce electrode passivation. In some embodiments, the catalyst coating layer can reduce electrode wear. In some embodiments, the surface of the electrode core may be at least partially covered by an intermediate layer made of a mixture. The intermediate layer may include a mixture or alloy made of titanium and tantalum, or a mixture or alloy made of titanium and palladium. In some embodiments, the intermediate layer may be a mixture or alloy of titanium and tantalum, or a mixture or alloy of titanium and palladium. The intermediate layer may be at least partially covered by a catalyst coating layer made of a mixture. In some embodiments, the catalyst coating layer may be a mixture made of iridium oxide and tantalum oxide. In some embodiments, the catalyst coating layer may be made of iridium oxide and tantalum oxide, or a mixture made substantially of iridium oxide and tantalum oxide.

[0059] In some embodiments, the electrode may comprise a conductive substrate or core, an intermediate layer covering at least a portion of the surface of the conductive core, comprising a mixture or alloy of titanium and tantalum, or a mixture or alloy of titanium and palladium, or substantially a mixture or alloy thereof, and a catalyst coating layer covering at least a portion of the intermediate layer, comprising a mixture of iridium oxide and tantalum oxide. In some embodiments, the electrode may comprise substantially (almost) a conductive core, an intermediate layer covering at least a portion of the surface of the conductive core, comprising a mixture or alloy of titanium and tantalum, or a mixture or alloy of titanium and palladium, and a catalyst coating layer covering at least a portion of the intermediate layer, comprising a mixture of iridium oxide and tantalum oxide. In some embodiments, the electrode may consist of a conductive core, an intermediate layer covering at least a portion of the surface of a conductive substrate, the intermediate layer being composed of a mixture or alloy of titanium and tantalum, or a mixture or alloy of titanium and palladium, and a catalyst coating layer covering at least a portion of the intermediate layer, the catalyst coating layer being composed of a mixture of iridium oxide and tantalum oxide.

[0060] The electrode substrate or core can be any conductive core. The electrode core can be any substrate having sufficient mechanical strength to support the intermediate layer and catalyst coating layer. The electrode core can be any substrate that is corrosion-resistant when exposed to the internal environment of the electrolytic cell. The electrode core may be a metal. In some embodiments, the electrode core may be a valve metal or an alloy thereof. The valve metal is any of the transition metals of Group IV and Group V of the periodic table, including titanium, vanadium, zirconium, niobium, hafnium, and tantalum. In some embodiments, suitable valve metals include titanium, zirconium, niobium, and tantalum. In some embodiments, the electrode core is preferably composed of titanium, made of titanium, or substantially made of titanium. Titanium may be preferred due to its availability, chemical properties, and low cost. The titanium core may be an alloy of titanium containing trace amounts of other metals, such as palladium, and may be Grade 1 or Grade 2 titanium.

[0061] The interlayer may consist of a mixture or alloy of titanium and tantalum, or a mixture or alloy of titanium and palladium. In some embodiments, the interlayer may consist substantially of a mixture of titanium and tantalum, or a mixture or alloy of titanium and palladium. In some embodiments, the interlayer may consist of a mixture or alloy of titanium and tantalum, or a mixture or alloy of titanium and palladium. The tantalum in the interlayer may be at any weight concentration such that desired properties are achieved, for example, electrode passivation or reduced wear, or increased interlayer life. The weight concentration of tantalum is the weight of tantalum relative to the total weight of the interlayer. In some embodiments, the weight concentration of tantalum in the Ti / Ta interlayer is in the range of 40 wt% to 60 wt%. In some embodiments, the interlayer may have a portion of it as an oxide of titanium or tantalum, or a mixed metal oxide of titanium and tantalum. The oxide may account for 5 to 10 wt% of the interlayer. The interlayer contains an oxide gradient, with the highest concentration of oxides present on the outer surface of the interlayer, and the oxide concentration decreasing as you move further into the interlayer.

[0062] The catalyst coating layer may consist of a mixture of iridium oxide (IrO2) and tantalum oxide (Ta2O5). In some embodiments, the catalyst coating layer may consist of substantially a mixture of IrO2 and Ta2O5. In some embodiments, the catalyst coating layer may consist of iridium oxide (IrO2) and Ta2O5. The iridium oxide may be at any weight concentration such that desired properties, such as electrode passivation or wear reduction, are achieved. The weight concentration of iridium oxide is the weight of iridium oxide relative to the total weight of the catalyst coating layer. In some embodiments, the weight concentration of iridium oxide is in the range of 40 wt% to 90 wt%, or 65 wt% to 90 wt%. In some embodiments, the weight concentration of iridium oxide in the catalyst coating layer is approximately 65 wt%.

[0063] The electrode core may be coated with an intermediate layer and a catalyst coating layer according to any coating process that can provide a homogeneous or substantially homogeneous dispersion of the material onto a desired surface. For example, the intermediate layer can be applied to the electrode substrate by physical vapor deposition (e.g., magnetron sputtering) or chemical vapor deposition. The catalyst coating layer can be applied to the intermediate layer by brushing, rolling, dipping, spraying, sputtering, evaporation, atomic layer deposition, or molecular layer deposition. The intermediate layer may be coated with the catalyst coating layer according to a thermal oxidation method.

[0064] Magnetron sputtering is a physical vapor deposition (PVD) technique used to deposit thin films onto substrates. This technique uses a magnetron cathode and an inert gas (usually argon), which is ionized to generate plasma. This plasma sputters the material from the target, depositing it as a thin film onto the substrate.

[0065] To fabricate electrodes, titanium and tantalum alloys must be deposited onto a titanium core using magnetron sputtering. The specific equipment and operating parameters required for this process may depend on the desired properties of the alloy, such as its composition, thickness, and adhesion to the substrate.

[0066] General guidelines for selecting magnetron sputtering equipment and operating parameters include the following:

[0067] Magnetron sputtering equipment: For stable and reliable thin-film deposition of alloys, high-quality magnetron sputtering equipment is necessary. This equipment must be able to maintain a high vacuum and precisely control the deposition process parameters.

[0068] Target material: The target material must be a high-purity alloy of titanium and tantalum with the desired composition and uniformity.

[0069] Operating parameters: Operating parameters that affect the deposition process include power input, gas flow rate, pressure, and substrate temperature. The specific parameters used depend on the desired properties of the deposited alloy.

[0070] Substrate preparation: The substrate, in this case the titanium core (e.g., Grade 1 titanium core), needs to be cleaned and prepared before deposition to ensure good adhesion and uniformity of the deposited film.

[0071] The appropriate inert gas atmosphere, vacuum pressure range, and substrate temperature for magnetron sputtering of titanium and tantalum may vary depending on several factors, including the specific equipment used, the desired properties of the deposited film, and the process requirements of the application.

[0072] Inert Gas Atmosphere: Argon is the most commonly used inert gas for magnetron sputtering of metals and alloys, including titanium and tantalum. Argon gas is used to generate a plasma that sputters the target material and deposits it onto the substrate. To ensure a clean deposition process, the argon gas used must be of high purity.

[0073] Vacuum pressure: The vacuum pressure during magnetron sputtering is typically 10 -2 ~10 -6 This is in the Torr range. The actual pressure used will vary depending on factors such as the size of the chamber, the desired deposition rate, and the specific target material. To prevent contamination and obtain a high-quality film, it is necessary to maintain vacuum pressure throughout the entire deposition process.

[0074] Substrate Temperature: The substrate temperature during magnetron sputtering of titanium and tantalum is typically in the range of 100°C to 500°C. The actual temperature used varies depending on the specific application and the desired properties of the film. Increasing the substrate temperature improves adhesion and film density, but it may also increase the risk of thermal damage to the substrate.

[0075] Magnetron sputtering equipment manufacturers include AJA International, Buhler Leybold Optics, Kurt J. Lesker Company, Semicore Equipment Inc., Plasma Quest Ltd., and Denton Vacuum.

[0076] The electrode core is first prepared for the application of the intermediate layer. For example, the electrode core is treated or cleaned to receive the intermediate film and catalyst coating layer, or to obtain a surface to which the intermediate film readily adheres. Cleaning of the electrode core can be carried out by chemical degreasing, electrolytic degreasing, or treatment with oxidizing acids. The electrode core can be prepared in any way suitable for removing or minimizing contaminants, promoting proper adhesion of the intermediate layer to the core surface, and producing a high surface roughness that can reduce the effective current density of the coated metal surface and potentially lower the operating potential of the electrode. If the anode has a long lifespan, downtime and tank maintenance will be reduced, and operating costs will be lowered. For example, the electrode core can be prepared by cleaning, sandblasting, etching, and / or pre-oxidation processes. Other methods for preparing the electrode core include plasma spraying, molten spraying with ceramic oxide particles, molten spraying of a valve metal layer onto the electrode substrate, grit blasting with sharp abrasive grains, and annealing. Following cleaning of the electrode core, mechanical roughening treatment can be performed to prepare the surface for intermediate layer deposition. In some embodiments, if sandblasting is performed, an etching step may be carried out. In some embodiments, the mechanical roughening process may be flame spray application of a mixture of fine particles of metal powder.

[0077] In some embodiments, a porous oxide layer can be applied to the electrode core to fix the intermediate layer to the core. For example, the oxide layer can be flame-sprayed or plasma-sprayed onto the electrode core before applying an electrochemically active substance. In some embodiments, the thermally sprayed material may consist of a metal oxide or metal nitride pre-coated with electrocatalytically active particles.

[0078] The catalytic coating layer can be applied by a thermal oxidation method, in which the components of the catalytic coating layer are prepared in a molar ratio suitable for imparting desired properties or effects to the resulting electrode. For example, the desired effect or property may be extending the service life by reducing wear and / or avoiding passivation.

[0079] The catalyst coating layer can be dried in a furnace at a first temperature for a first time, and then dried in a first or second furnace at a second temperature for a second time. One or both of the first and second temperatures may be high. In some embodiments, the catalyst coating layer can be dried in a first furnace at a temperature of about 80°C to about 120°C. For example, the catalyst coating layer may be dried in a first furnace at about 90°C. In some embodiments, the catalyst coating layer can be dried in a first furnace for about 5 minutes to about 3 hours. For example, the catalyst coating layer can be dried in a first furnace for about 5 minutes to about 60 minutes. In some embodiments, the catalyst coating layer can be dried in a first furnace for about 10 minutes.

[0080] Next, the catalyst coating layer may be dried in a second furnace. The second furnace may include an oxygen source. For example, the oxygen source may be air. In some embodiments, the catalyst coating layer can be dried in the second furnace at a temperature of about 250°C to about 750°C. For example, the catalyst coating layer may be dried in the second furnace at about 500°C. In some embodiments, the catalyst coating layer can be dried in the first furnace for about 5 minutes to about 3 hours. For example, the catalyst coating layer may be dried in the second furnace for about 1 hour. To achieve the desired material load, the material for the catalyst coating layer may be applied one or more times.

[0081] In some embodiments, the intermediate layer and / or catalyst coating layer is approximately 0.2 g / m². 2 ~Approx. 3.5g / m 2 It can have a metal load. The thickness of the intermediate layer and / or catalyst coating layer may not depend on the dimensions of the electrode.

[0082] The electrodes can be installed in an electrolytic cell. In one embodiment, the electrolytic cell also has a power supply for supplying current to the electrodes of the electrolytic cell. In some embodiments, the current source may be a DC power supply. In the direction of current, one electrode typically functions as the anode and its opposite electrode typically functions as the cathode.

[0083] The electrolytic cell may be part of a system. For example, the electrolytic cell can be used in a wastewater treatment system. In some embodiments, the electrolytic cell can be used in a municipal wastewater treatment system or an industrial wastewater treatment system. In some embodiments, the electrolytic cell can be used in a chemical treatment system. In some embodiments, the electrolytic cell can be used in an industrial process water system. For example, the electrolytic cell may be used in an electrolytic chlorine generation system. The system may consist of a saltwater source. For example, the system may consist of a ballast water supply source. In some embodiments, the system may further include a water outlet. For example, the system may include a drinking water outlet. In some embodiments, the system may further include a water storage unit fluidly connected to the water outlet. In some embodiments, the system may further include a contaminant outlet. For example, the system may include a chlorine solution outlet. In some embodiments, the chlorine solution outlet may include a sodium hypochlorite solution outlet. In some embodiments, the system may include a contaminant storage unit fluidly connected to the contaminant outlet.

[0084] Figures 1A and 1B show some of the electrodes according to the present disclosure. The electrode 100 comprises a substrate or a core 101. The core 101 may be any conductive substrate. The core 101 may be a metal. In some embodiments, the core 101 may be a valve metal. For example, the core 101 may be made of titanium, vanadium, zirconium, niobium, hafnium, or tantalum. In some embodiments, the core 101 is preferably made of titanium in its pure form or as an alloy, for example, Grade 1 or Grade 2 titanium, or substantially made of such titanium. The core 101 can be prepared for the application of an interlayer. For example, the core 101 may be treated or cleaned to accept an interlayer or to obtain a surface to which an interlayer readily adheres. Cleaning of the core 101 can be carried out by chemical degreasing, electrolytic degreasing, or treatment with an oxidizing acid. The core 101 can be prepared by any method suitable for removing or minimizing contaminants, promoting proper adhesion of the intermediate layer to the surface of the core 101, and achieving a high surface roughness that can reduce the effective current density on the coated metal surface and thus also reduce the electrode operating potential. For example, the core 101 can be prepared by cleaning, sandblasting, etching, and / or pre-oxidation processes. Other methods for preparing the core 101 may include plasma spraying, molten spraying with ceramic oxide particles, molten spraying of a valve metal layer onto the electrode core, grit blasting with sharp abrasive particles, and annealing. Following cleaning of the core 101, mechanical roughening can be performed to prepare the surface for intermediate layer deposition. In some embodiments, if cleaning by sandblasting is performed, an etching step may be performed thereafter. In some embodiments, the mechanical roughening step may be flame spray coating of a fine particle mixture of metal powder.

[0085] The core 101 may be coated with an interlayer 102. The interlayer 102 may cover at least a portion of the surface of the core 101. The interlayer 102 may consist of a mixture or alloy of titanium and tantalum, or a mixture or alloy of titanium and palladium (e.g., Grade 7 or Grade 11 titanium). The interlayer 102 may consist of titanium or tantalum at any weight concentration such that at least one of the desired properties, such as electrode passivation or wear reduction, is achieved. In some embodiments, the weight concentration of titanium or tantalum in the interlayer 102 is in the range of 40 wt% to 60 wt%. In some embodiments, the weight concentration of titanium or tantalum in the interlayer 102 is in the range of 45 wt% to 55 wt%. The interlayer 102 can be applied to the surface of the core 101 by any known coating process. For example, the interlayer 102 can be applied to the surface of the core 101 by physical vapor deposition (evaporation or sputtering) or chemical vapor deposition. Although the interlayer 102 is shown on only one side of the core 101 in Figures 1A and 1B, it should be understood that the interlayer 102, like the catalyst coating layer 103, may be placed on both sides or the entire surface of the core 101.

[0086] The interlayer 102 may be coated with a catalyst coating layer 103. The catalyst coating layer 103 may cover at least a portion of the interlayer 102. The catalyst coating layer 103 may consist of a mixture of iridium oxide (IrO2) and tantalum oxide (Ta2O5). The catalyst coating layer 103 may consist of IrO2 at any weight concentration such that desired properties, such as electrode passivation or reduced wear, are achieved. In some embodiments, the weight concentration of IrO2 in the catalyst coating layer 103 is in the range of 40 wt% to 90 wt% or 65 wt% to 90 wt%. In some embodiments, the weight concentration of IrO2 in the catalyst coating layer 103 is approximately 65 wt%. The catalyst coating layer 103 has a weight of 3 g / m². 2 From 70g / m 2It may also contain Ir. The catalyst coating layer 103 can be applied to the first coating layer 102 by brushing, rolling, or spraying. The catalyst coating layer 103 may also be applied to the intermediate layer 102 by a thermal oxidation method.

[0087] Referring next to Figure 2, an electrochemical system is provided. System 200 may include an electrolytic cell 210. The electrolytic cell 210 may include at least one electrode 100, as described above. The electrode 100 may be at least one of an anode and a cathode. In some embodiments, the electrode 100 is the anode. System 200 may further include a power supply 230 operably connected to the electrolytic cell 210. The power supply 230 may supply a DC current to the electrolytic cell 210. The power supply 230 may have, for example, 5 kA / m 2 ~20kA / m 2 The current can be supplied to the electrode 100 during this period. The power supply 230 can, for example, supply current to an anode area of ​​1 m² without anode peeling or corrosion. 2 It can supply a total charge exceeding 50mAh per unit.

[0088] One or more sensors 240 may be placed inside the electrolytic cell 210. The sensors 240 may be configured to measure the quality of the system 200. In some embodiments, the sensors 240 may be configured to measure one or more of the following: the pH of the system (e.g., the pH of the electrolyte), the temperature of the system (e.g., the temperature of the electrolyte), the conductivity of the electrolyte, and / or the current passing through the electrodes and electrolyte. The sensor(s) 240 may communicate with the controller 250 electrically or otherwise to provide the controller with signals indicating the measured characteristics of the system. The controller 250 may control one or more characteristics of the system. For example, the controller 250 may control the amperage from the power supply 230 to the system.

[0089] The electrodes described herein can be used as the cathode of an electrodeposition apparatus to allow a conductive substrate to function as the cathode of the electrodeposition apparatus, and as the anode of an electrodeposition apparatus to deposit metal onto the conductive substrate.

[0090] An example of a method for electrolytically depositing chromium onto a metal substrate may include the step of preparing an electrodeposition apparatus comprising a container, an anode placed in the container, and a metal substrate placed in the container. The anode includes a core formed of valve metal, an intermediate layer placed on the core and also made of a titanium-tantalum alloy, substantially a titanium-tantalum alloy, or composed of a titanium-tantalum alloy (with optionally a partially oxidized outer region), and a catalyst placed on the intermediate layer. An electrolyte containing the ionic form of chromium and one or more organic additives is introduced into the electrodeposition container. An electric current is passed from the anode to the metal substrate through the electrolyte to deposit chromium onto the metal substrate.

[0091] The anode may include a core made of titanium and a catalyst layer made of a mixed metal oxide of iridium and tantalum. 2 From 70g / m 2 For example, 10g / m 2 The catalyst layer may also contain iridium. The catalyst layer may contain iridium and tantalum in a mass ratio of 9:1 to 2:1. The catalyst layer is not limited to being a mixed metal oxide of iridium and tantalum, and may be formed of one or more of platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, and tantalum oxide.

[0092] The intermediate layer can be formed of titanium and tantalum in a weight ratio of 30:70 to 70:30. Alternatively or additionally, the intermediate layer may be formed of a palladium-containing titanium alloy, such as titanium grade 7, titanium grade 7H, titanium grade 11, titanium grade 16, titanium grade 16H, titanium grade 17, or titanium grade 19. The outer surface of the intermediate layer or the interface between the intermediate layer and the catalyst material layer may be at least partially oxidized.

[0093] The electrolyte may contain formic acid and / or sulfonic acid (e.g., methanesulfonic acid) as one or more organic additives. The electrolyte may be maintained at a pH of less than 0 to 4, 0 to 4, 1 to 4, or 2.5 to 3.5.

[0094] The current is measured in an anode area of ​​1 m². 2 It can be applied at 5-20kA per unit.

[0095] This method allows for the deposition of an anode without an intermediate layer, or with an intermediate layer formed of tantalum oxide or titanium oxide, compared to electrodeposition devices that include an anode without an intermediate layer or with an intermediate layer formed of tantalum oxide or titanium oxide, without anode peeling or corrosion, and with an anode area of ​​1 m². 2 This can involve a step of applying a larger amount of charge per MAh. Without anode peeling or corrosion, the anode area 1 m² 2 More than 50mAh of electrolyte may pass through the anode.

[0096] Another method that may be carried out in accordance with this disclosure is a method for electrolytically depositing a metal onto a metal substrate. This method may include the step of preparing an electrodeposition apparatus comprising a container, an anode placed in the container, and a metal substrate placed in the container. The anode comprises a core made of titanium, made of titanium, or made substantially of titanium; an intermediate layer placed on the core and made of a titanium-tantalum alloy or a palium-containing titanium alloy, or made substantially of the same alloy; and a catalyst material layer placed on the intermediate layer and made of one or more of the following: platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide, or made substantially of the same. An electrolyte comprising the ionic form of the metal and one or more organic additives may be introduced into the electrodeposition container. An electric current may be passed through the electrolyte from the anode to the metal substrate to deposit the metal onto the metal substrate.

[0097] The anode may have a core made of either titanium grade 1 or titanium grade 2, consisting of one or substantially one of the two.

[0098] The step of introducing an electrolyte into the electrodeposition container may include introducing an aqueous solution containing one of chromium ions, tin ions, copper ions, or zinc ions into the electrodeposition container.

[0099] The step of introducing the electrolyte into the electrodeposition container may include the step of introducing an aqueous solution containing chromium ions, and the method may further include the step of maintaining the electrolyte under conditions in which the chromium ions are mainly present as Cr(III).

[0100] The pH of the electrolyte can be maintained between less than 0 and 4, 0 and 4, 1 and 4, or 2.5 and 3.5.

[0101] The catalyst material layer, positioned on the intermediate layer of the anode, consists of one or more of the following: platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide.

[0102] Formic acid or sulfonic acid (e.g., methanesulfonic acid) may be introduced into the electrolyte as one or more organic additives.

[0103] Without anode peeling or corrosion, anode area 1 m² 2 It is possible to pass more than 50mAh of charge through the anode.

[0104] The introduction of an electrolyte into the electrodeposited container may include the introduction of sulfuric acid into the electrodeposited container.

[0105] Another method for electrolytically depositing a metal onto a substrate as disclosed herein may include the steps of introducing an electrolyte comprising the ionic form of the metal and one or more organic additives into an electrodeposition vessel, and applying an electric current through the electrolyte from an anode in electrical contact with the electrolyte to a cathode within the electrodeposition vessel. The anode may include a substrate made of valve metal, or substantially made of valve metal, an intermediate layer disposed on the substrate and also made of a titanium-tantalum alloy, or substantially made of a titanium-tantalum alloy, and a catalyst material layer disposed on the intermediate layer.

[0106] In a method for electrodepositing chromium onto a substrate, the anode can be supplied such that it comprises a metal substrate having a catalyst layer containing a mixed metal oxide of iridium, and an intermediate layer disposed between the substrate and the catalyst layer. The intermediate layer may include an alloy of titanium and tantalum, or an alloy of titanium and palladium, such as Grade 7 or Grade 11 titanium.

[0107] The catalyst layer may be a mixed metal oxide of iridium and tantalum.

[0108] The intermediate layer may include an outer surface region that is nearly free of or partially oxidized titanium or tantalum oxides.

[0109] The metal substrate may be made of valve metal.

[0110] The apparatus for electrolytic deposition uses an anode with a current of approximately 10 to 20 kA / m². 2 It may include a power supply for applying the light.

[0111] Another method for facilitating the electrolytic deposition of chromium onto a metal substrate by applying an electric current from an anode through the electrolyte to the metal substrate, thereby accommodating the deposition of chromium on a metal substrate from an electrolyte containing ionic form of chromium and one or more organic additives in an electrodeposition vessel, includes the step of preparing an anode. The anode includes a core made of valve metal, made of valve metal, or made substantially of valve metal; an intermediate layer disposed on the core and made of one of the titanium-tantalum alloy or titanium-palladium alloy, made of one of the alloys, or made substantially of one of the alloys; and a catalyst material layer disposed on the intermediate layer.

[0112] The anode may be prepared as having a core made of titanium, consisting of titanium, or substantially made of titanium, or as having a catalyst material layer made of a mixed metal oxide of iridium and tantalum, or substantially made of the mixed metal oxide.

[0113] The catalyst material layer may alternatively be formed from one or more of the following: platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide.

[0114] The catalyst material layer has a density of 3 g / m². 2 More than 70g / m 2 It may also be formed from the following iridium, for example, about 10 g / m² 2 It may be formed of iridium.

[0115] The anode may be prepared as having an intermediate layer of titanium and tantalum formed in a weight ratio of 30:70 to 70:30, and / or having a catalytic material layer of iridium and tantalum formed in a mass ratio of 9:1 to 2:1.

[0116] The electrolyte may have a pH of 1 to 4. One or more organic additives in the electrolyte may include either formic acid or sulfonic acid.

[0117] The step of preparing the anode is to ensure that the anode is not damaged, before the anode is damaged, and the anode area is 1 m². 2 The step of preparing an anode having a structure and composition configured to conduct more charge per unit MAh than an anode without an intermediate layer or having an intermediate layer formed of tantalum oxide, for example, before the anode is damaged, with an anode area of ​​1 m² 2 The procedure may include the step of preparing an anode having a structure and composition configured to conduct more than 50 MAh of charge per unit area.

[0118] Another method for facilitating the electrolytic deposition of a metal onto a conductive substrate by applying an electric current from an anode through an electrolyte to the conductive substrate, thereby depositing the metal onto the conductive substrate from an ionic form of the metal and one or more organic additives in an electrodeposition container, includes the step of preparing the anode. The anode includes a core formed of titanium; an intermediate layer disposed on the core and consisting substantially of one of the following: titanium-tantalum alloy, titanium grade 7, titanium grade 7H, titanium grade 11, titanium grade 16, titanium grade 16H, titanium grade 17, or titanium grade 19; and a catalyst material layer disposed on the intermediate layer and formed of one or more of the following: platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide.

[0119] The anode can be prepared as having a core formed from either titanium grade 1 or titanium grade 2.

[0120] The electrolyte may include an aqueous solution containing chromium ions, tin ions, zinc ions, or copper ions.

[0121] The electrolyte contains an aqueous solution containing chromium ions and can be maintained under conditions where the chromium ions are mainly present as Cr(III). For example, the pH of the electrolyte can be maintained between 1 and 4. One or more organic additives may include formic acid, sulfuric acid, or sulfonic acid.

[0122] The anode can be prepared as having a catalyst material layer formed of one or more of platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, palladium, tantalum, or tantalum oxide.

[0123] Before the anode is damaged, the anode area is 1 m². 2 It can be prepared with a structure and composition configured to allow more than 50 mAh to pass through per unit area.

[0124] Another method for facilitating the electrolytic deposition of a metal onto a substrate from an electrolyte containing an ionic form of the metal and one or more organic additives, by applying an electric current through the electrolyte from an anode in electrical contact with the electrolyte in the electrodeposition vessel to a cathode, may include the step of preparing an anode. The anode may include a substrate formed of valve metal, an interlayer disposed on the substrate and also formed of a titanium-tantalum alloy, and a catalyst disposed on the interlayer.

[0125] In a method for electrodepositing chromium onto a substrate according to this disclosure, an anode can be supplied comprising a metal substrate having a catalyst layer containing a mixed metal oxide of iridium, and an intermediate layer disposed between the substrate and the catalyst layer. The intermediate layer may contain an alloy of titanium and tantalum, or titanium and palladium. The catalyst layer may also be a mixed metal oxide of iridium and tantalum. The intermediate layer may optionally contain substantially no titanium or tantalum oxide, except for its outer surface region. The metal substrate may be made of valve metal.

[0126] The anode has an output of approximately 5 to 20 kA / m². 2It may be supplied in a structure and composition configured to pass through the anode.

[0127] A method for modifying a system for electrodepositing Cr(III) from an organic electrolyte onto a conductive substrate in accordance with this disclosure may include replacing the anode of the system with the following anode, the anode comprising a core made of titanium, made of titanium, or made substantially of titanium; an intermediate layer disposed on the core, made of a titanium-tantalum alloy, made of a titanium-tantalum alloy, or made substantially of a titanium-tantalum alloy; and a catalyst disposed on the intermediate layer, made of one or more of platinum, iridium, iridium oxide, ruthenium, ruthenium oxide, tantalum, palladium, or tantalum oxide, comprising one or more of the catalyst, comprising one or more of the catalyst.

[0128] The functionality and advantages of these and other embodiments will be better understood from the following non-limiting embodiments. These embodiments are intended to be illustrative in nature and are not intended to limit the scope of the embodiments discussed herein. [Examples]

[0129] Titanium electrode core (grade 1) in hydrochloric acid (6.5 mol L) -1 The material was etched at 90°C for 90 minutes, and then coated with a Ti / Ta metal interlayer (Ti 55-60 wt.%) using DC magnetron sputtering with a Full-E FE-2400 sputtering system. The sputtering was performed in 5-10 -3 The process was carried out at Pa and 200°C. Afterward, the core and interlayer were annealed at 540°C for 1 hour. Finally, Ir(H2IrCl6) and Ta(tantalum ethoxide Ta2(OC2H5)) were used. 10 A butanol solution containing ) was coated using a spin coater, with an Ir loading amount of 10 g m -2 The intermediate layer was coated until the desired result was reached. The mass ratio of Ir to Ta in the butanol solution was varied from 9:1 to 2:1.

[0130] Similar electrodes were fabricated, but a Ta2O5 interlayer was used instead of a Ti / Ta metal interlayer.

[0131] Both electrodes were placed in an electrolyte solution containing 1M Na2SO4 + 1M HCOONa at 43°C. Each electrode was used as an anode, and 1m of each electrode was used. 2 A current density of 15A was applied per unit. The electrode using the Ti / Ta interlayer had a current capacity of 60mAh / m². 2 While it showed a lifespan of 25 MAh / m², the electrode using a Ta2O5 interlayer had a lifespan of 25 MAh / m². 2 The device was damaged. The damage time was defined as the time it took for the initial voltage applied to the electrode to double.

[0132] Thus, electrodes with a Ti / Ta intermediate layer showed more than twice the lifespan of electrodes with a Ta2O5 intermediate layer.

[0133] Now, having described several exemplary embodiments of this disclosure, it will be apparent to those skilled in the art that what has been stated is merely illustrative and not limiting. Numerous modifications and other embodiments are within the scope of those skilled in the art and are intended to be included within the scope of this disclosure. In particular, many of the examples presented herein involve specific combinations of method actions or system elements, but it should be understood that those actions and those elements may be combined in other ways to achieve the same objective.

[0134] Those skilled in the art should understand that the parameters and configurations described herein are illustrative, and that actual parameters and / or configurations will depend on the specific application in which the system and technology of the present invention are used. Those skilled in the art should also be able to recognize or confirm, without the use of routine experimentation, that certain embodiments of this disclosure are equivalent. Therefore, it should be understood that the embodiments described herein are presented only in illustrative terms, and that, within the scope of the appended claims and their equivalents, the present invention may be carried out in ways other than those specifically described.

[0135] Furthermore, this disclosure is directed toward each feature, system, subsystem, or technology described herein, and it should be understood that any combination of two or more features, systems, subsystems, or technologies described herein is deemed to fall within the scope of this disclosure as embodied in the claims, provided that such features, systems, subsystems, and technologies are not mutually inconsistent. Moreover, acts, elements, and features discussed only in combination with one embodiment are not intended to be excluded from similar roles in other embodiments.

[0136] As used herein, the term “plurality” refers to two or more items or components. The terms “comprising,” “including,” “carrying,” “having,” “containing,” and “involving” are open-ended terms, both herein and in the claims, meaning “including but not limited to.” Therefore, the use of such terms means to include the items listed thereafter, their equivalents, and any additional items. In the claims, only the transitional phrases “consisting of” and “consisting essentially of” are closed or semi-closed transitional phrases, respectively. In the claims, the use of ordinal terms such as "first," "second," and "third" to modify claim elements does not in itself imply priority, precedence, order, or temporal order in which the actions of a method are performed for one claim element relative to other claim elements, but is simply used as a label to distinguish one claim element having a certain name from other claim elements having the same name (however, because ordinal terms are used).

Claims

1. A method for electrolytically depositing chromium onto a metal substrate by applying an electric current from an anode to the metal substrate through an electrolyte, wherein the electrolyte contains chromium in ionic form and one or more organic additives in an electrodeposition container, the method comprising the step of preparing the anode, the anode comprising: a core made of valve metal; an intermediate layer disposed on the core and composed of one of the following: titanium-tantalum alloy, titanium-palladium alloy, titanium grade 7, titanium grade 7H, titanium grade 11, titanium grade 16, titanium grade 16H, titanium grade 17, or titanium grade 19, containing titanium and tantalum in a weight ratio of 30:70 to 70:30, with a metal loading amount of 0.2 g / m² to 3.5 g / m²; and a catalyst material layer disposed on the intermediate layer, comprising a catalyst material layer composed of a mixed metal oxide of iridium and tantalum, containing iridium and tantalum in a mass ratio in the range of 9:1 to 2:

1.

2. A method according to claim 1, wherein the anode is prepared having the core made of titanium.

3. The method according to claim 1, wherein the catalyst material layer further comprises one or more of platinum, ruthenium, ruthenium oxide, or palladium.

4. In the method according to claim 1, the catalyst material layer is 3 g / m ２ ~70g / m ２ A method including iridium.

5. The method according to claim 1, wherein the intermediate layer comprises 40 wt% to 60 wt% titanium.

6. The method according to claim 1, wherein the intermediate layer contains 10 wt% or less of titanium or tantalum oxide based on the weight of the intermediate layer.

7. A method according to claim 1, wherein the electrolyte has a pH of 0 to 4.

8. The method according to claim 7, wherein the pH of the electrolyte is 2.5 to 3.

5.

9. A method for electrolytically depositing a metal onto a conductive substrate by applying an electric current from an anode to the conductive substrate through an electrolyte, thereby facilitating the electrolytic deposition of the metal onto the conductive substrate from an electrolyte containing the ionic form of the metal and one or more organic additives in an electrodeposition container, the method comprising the step of preparing the anode, the anode comprising a core made of titanium and one of the following arranged on the core: a titanium-tantalum alloy containing titanium and tantalum in a weight ratio of 30:70 to 70:30, a titanium-palladium alloy, titanium grade 7, titanium grade 7H, titanium grade 11, titanium grade 16, titanium grade 16H, titanium grade 17, or titanium grade 19, with a metal loading amount of 0.2 g / m² to 3.5 g / m² A method comprising the step of preparing an anode, the anode comprising an intermediate layer and a catalyst material layer disposed on the intermediate layer, the anode being composed of a mixed metal oxide of iridium and tantalum, the iridium and tantalum being in a mass ratio in the range of 9:1 to 2:

1.

10. A method according to claim 9, wherein the anode is prepared having the core which is made of titanium grade 1 or titanium grade 2.

11. The method according to claim 9, wherein the electrolyte comprises an aqueous solution containing one of chromium ions, tin ions, zinc ions, and copper ions.

12. The method according to claim 11, wherein the electrolyte comprises an aqueous solution containing chromium ions, and is maintained under conditions in which the chromium ions mainly exist as Cr(III).

13. A method according to claim 9, wherein the pH of the electrolyte is maintained between 0 and 4.

14. The method according to claim 9, wherein the electrolyte comprises either sulfuric acid or sulfonic acid.

15. In the method according to claim 9, the anode is 3 g / m ２ ~70g / m ２ A method prepared having the catalyst material layer containing iridium.

16. The method according to claim 9, wherein the intermediate layer comprises 40 wt% to 60 wt% titanium.

Images