TW201819687A - Electrode for electrolysis - Google Patents

Abstract

This electrode for electrolysis is provided with a conductive base material and a catalyst layer that is formed on the surface of the conductive base material. The catalyst layer contains elemental ruthenium, elemental iridium, elemental titanium and at least one first transition metal element selected from the group consisting of Sc, V, Cr, Fe, Co, Ni, Cu and Zn; the content ratio of the first transition metal element contained in the catalyst layer relative to 1 mole of the elemental titanium is 0.25% by mole or more but less than 3.4% by mole; and the D value serving as an index for the electric double layer capacity of this electrode for electrolysis is from 120 C/m2 to 420 C/m2 (inclusive).

Description

Electrolysis electrode

The present invention relates to an electrode for electrolysis, a method for manufacturing the same, and an electrolytic cell including the electrode for electrolysis.

The ion-exchange membrane method of salt electrolysis is a method in which brine is electrolyzed using an electrode for electrolysis to produce caustic soda, chlorine, and hydrogen. In the salt-electrolysis process of the ion-exchange membrane method, in order to reduce power consumption, a technique for maintaining a low electrolytic voltage for a long period of time is required. If the detailed content of the electrolytic voltage is analyzed in detail, it is clear that in addition to the theoretically required electrolytic voltage, it also includes the voltage caused by the resistance of the ion exchange membrane and the structural resistance of the electrolytic cell, and serves as the electrode for electrolysis Over voltage of anode and cathode, voltage due to the distance between anode and cathode, etc. In addition, if the electrolysis is continued for a long period of time, a voltage rise due to various reasons such as impurities in the brine may occur. Various studies have been conducted on the above-mentioned electrolytic voltage in order to reduce the overvoltage of the anode for generating chlorine. For example, Patent Document 1 discloses a technology of an insoluble anode formed by coating an oxide of a platinum group metal such as ruthenium on a titanium substrate. This anode is called DSA (registered trademark, Dimension Stable Anode). Also, Non-Patent Document 1 describes a change in sodium electrolysis technology using DSA. Regarding the above-mentioned DSA, various improvements have been implemented so far, and research on performance improvement has been conducted. For example, Patent Document 2 reports an electrode for chlorine generation in which platinum and palladium are alloyed with a lower chlorine overvoltage and a higher oxygen overvoltage of palladium in the platinum group. Patent Documents 3 and 4 propose an electrode in which a surface of a platinum-palladium alloy is oxidized and a palladium oxide is formed on the surface. Further, Patent Document 5 proposes an electrode coated with an external catalyst layer containing an oxide of tin as a main component and containing oxides of ruthenium, iridium, palladium, and niobium. In order to obtain high-purity chlorine with a relatively low oxygen concentration through this electrode, attempts have been made to suppress the oxygen generation reaction in the anode simultaneously with the generation of chlorine. [Prior Art Literature] [Patent Literature] [Patent Literature 1] Japanese Patent Publication No. 46-021884 [Patent Literature 2] Japanese Patent Publication No. 45-11014 [Patent Literature 3] Japanese Patent Publication No. 45-11015 Gazette [Patent Document 4] Japanese Patent Publication No. 48-3954 [Patent Document 5] Japanese Patent Publication No. 2012-508326 [Non-Patent Document] [Non-Patent Document 1] Yoko Aikawa "Systematic Investigation Report, Episode 8", issued by the National Museum of Science and Technology, March 30, 2007, p32

[Problems to be Solved by the Invention] However, the previous anodes such as DSA described in Patent Document 1 have the following problems: the overvoltage immediately after the start of electrolysis is high, and it stabilizes to a low overvoltage due to the activation of the catalyst A certain period of time is required, and therefore, power loss occurs during electrolysis. In addition, the chlorine-generating electrodes described in Patent Documents 2 to 4 may have a high overvoltage and low durability. Furthermore, when manufacturing the electrodes described in Patent Documents 3 and 4, in addition to using an alloy as the base material, it is also necessary to perform alloying by reduction after forming an oxide on the base material by thermal decomposition, and then by The complicated steps such as electrolytic oxidation and palladium oxidation need to be greatly improved in terms of manufacturing method, even in terms of practical aspects. The electrode system described in Patent Document 5 has a certain effect on improving the electrolysis duration (electrode life) of palladium, which lacks chemical resistance, but it cannot be said that the overvoltage generated by chlorine is sufficiently low. As described above, the techniques described in Patent Documents 1 to 5 and Non-Patent Document 1 cannot achieve an overvoltage that is sufficiently low in the initial stage of electrolysis, and can continuously achieve electrolysis with low voltage and low power consumption for a long time. The present invention has been made to solve the above problems. Therefore, an object of the present invention is to provide an electrode for electrolysis that can reduce overvoltage in the initial stage of electrolysis, and can continuously perform electrolysis with low voltage and low power consumption for a long period of time, a method for manufacturing the same, and electrolysis provided with the electrode groove. [Technical Means for Solving the Problem] The present inventors and the like have made intensive studies in order to solve the above problems. As a result, it was found that by adjusting the value of the electric double-layer capacitance index of an electrolytic electrode having a catalyst layer containing a specific metal element at a specific ratio to a specific range, the initial stage of electrolysis can be reduced. Voltage, and can achieve electrolysis with low voltage and low power consumption for a long period of time, so that the present invention is completed. That is, the present invention is as follows. [1] An electrode for electrolysis, comprising: a conductive substrate and a catalyst layer formed on a surface of the conductive substrate, wherein the catalyst layer includes a ruthenium element, an iridium element, a titanium element, and At least one first transition metal element selected from the group consisting of Sc, V, Cr, Fe, Co, Ni, Cu, and Zn, and the first transition metal element included in the catalyst layer is 1 mole relative to the titanium element. The ear content ratio is 0.25 mol% or more and less than 3.4 mol%, and the D value of the above-mentioned electrode for electrolysis to be an electric double-layer capacitor is 120 C / m ² or more and 420 C / m ² or less. [2] The electrode for electrolysis according to [1], wherein the first transition metal element and the solid solution of ruthenium oxide, iridium oxide, and titanium oxide form a solid solution. [3] The electrode for electrolysis according to [1] or [2], wherein the first transition metal element includes at least one metal element selected from the group consisting of vanadium, cobalt, copper, and zinc. [4] The electrode for electrolysis according to any one of [1] to [3], wherein the first transition metal element includes a vanadium element. [5] The electrode for electrolysis according to any one of [1] to [4], wherein the content ratio of the first transition metal element to all the metal elements contained in the catalyst layer is 10 mol% or more And 30 mol% or less. [6] The electrode for electrolysis according to any one of [1] to [5], wherein a content ratio of the first transition metal element contained in the catalyst layer to 1 mol of the ruthenium element is 0.3 mol Above the ear and less than 2 moles. [7] The electrode for electrolysis according to any one of [1] to [6], wherein the D value is 120 C / m ² or more and 380 C / m ² or less. [8] A method for manufacturing an electrode for electrolysis, which is a method for manufacturing the electrode for electrolysis according to any one of [1] to [7], which has the following steps: preparing a ruthenium compound, an iridium compound, A coating liquid of a titanium compound and a compound containing the first transition metal element; forming the coating film by coating the coating liquid on at least one side of the conductive substrate; and firing the coating in an oxygen-containing environment Film to form the catalyst layer. [9] An electrolytic cell provided with the electrode for electrolysis according to any one of [1] to [7]. [Effects of the Invention] According to the present invention, it is possible to provide an electrode for electrolysis that can reduce overvoltage in the initial stage of electrolysis and can achieve electrolysis with low voltage and low power consumption for a long period of time.

Hereinafter, the form (hereinafter, abbreviated as "this embodiment") for implementing this invention is demonstrated in detail. The following embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following contents. The present invention can be appropriately modified and implemented within the scope of the gist thereof. The electrode for electrolysis according to this embodiment includes a conductive substrate and a catalyst layer formed on the surface of the conductive substrate. The catalyst layer includes a ruthenium element, an iridium element, a titanium element, and a material selected from the group consisting of rhenium, At least one first transition metal element in the group consisting of vanadium, chromium, iron, cobalt, nickel, copper, and zinc (hereinafter, these transition metal elements are also collectively referred to as "first transition metal element"). Furthermore, the electrode for electrolysis of this embodiment is configured as follows: the content ratio of the first transition metal element contained in the catalyst layer to the titanium element is 1 mol% or more and less than 3.4 moles %, The D value of the above-mentioned electrode for electrolysis to be an electric double-layer capacitor is 120 C / m ² or more and 420 C / m ² or less. In this embodiment, in addition to the ruthenium, iridium, and titanium elements in the catalyst layer, the first transition metal element is also used, thereby becoming an electrode for electrolysis as measured by X-ray photoelectron spectroscopy (XPS) The peak position of the peak belonging to Ru3d5 / 2 derived from RuO ₂ shifted from 280.5 eV of RuO _{2 to} the high binding energy side. In addition, the XPS charge correction is performed in such a way that the combined energy of Ti2p3 / 2 becomes 458.4 eV. The shift of the peak position of Ru3d5 / 2 to the high binding energy side indicates the state where Ru is oxidized due to the charge, and this state is considered to be due to the addition of the first transition metal element. For example, when vanadium is added as the first transition metal element, the following polarization occurs. RuO ₂ + VO ₂ → RuO ₂ ^{δ +} + VO ₂ ^δ- RuO ₂ ^{δ +} becomes the active adsorption site for chlorine adsorption, and it can reduce the overvoltage generated by chlorine by promoting the adsorption of chlorine. The gist of the present invention is not limited to the above-mentioned mechanism of action. Since the electrode for electrolysis of the present embodiment has the above-mentioned structure, when the electrode for electrolysis is used for electrolysis, the overvoltage in the initial stage of electrolysis can be reduced, and it can be sustained for a long time Realize electrolysis with low voltage and low power consumption. The electrode for electrolysis according to this embodiment can be preferably used as an electrode for generating chlorine, especially in salt electrolysis by an ion exchange membrane method. (Conductive base material) The electrode for electrolysis according to this embodiment is used in a high-concentration saline solution close to saturation and used in a chlorine gas generating environment. Therefore, as the material of the conductive substrate in this embodiment, a valve metal having corrosion resistance is preferred. The valve metal is not limited to the following, and examples thereof include titanium, tantalum, niobium, and zirconium. From the viewpoint of economy and affinity with the catalyst layer, titanium is preferred. The shape of the conductive substrate is not particularly limited, and an appropriate shape can be selected according to the purpose. For example, shapes such as an extended shape, a perforated plate, and a wire mesh are preferably used. The thickness of the conductive substrate is preferably 0.1 to 2 mm. In order to improve the adhesiveness with the catalyst layer, it is preferable that the contact surface of the conductive substrate and the catalyst layer be subjected to a surface area increasing treatment. The method of increasing the surface area is not limited to the following, and examples thereof include a sandblasting treatment using a cut wire, steel gravel, aluminum gravel, and the like; an acid treatment using sulfuric acid or hydrochloric acid, and the like. Among these treatments, it is preferable to perform a method of forming an unevenness on the surface of the conductive substrate by a sandblasting treatment, and then performing an acid treatment. (Catalyst layer) The catalyst layer formed on the surface of the conductive substrate subjected to the above-mentioned treatment includes a ruthenium element, an iridium element, a titanium element, and a first transition metal element. The ruthenium element, the iridium element, and the titanium element are preferably each in the form of an oxide. The ruthenium oxide is not limited to the following, and examples thereof include RuO ₂ and the like. The iridium oxide is not limited to the following, and examples include IrO ₂ and the like. The titanium oxide is not limited to the following, and examples thereof include TiO ₂ and the like. In the catalyst layer of this embodiment, it is preferable that the ruthenium oxide, iridium oxide, and titanium oxide form a solid solution. Ruthenium oxide, iridium oxide, and titanium oxide form a solid solution, and the durability of ruthenium oxide is further improved. The so-called solid solution usually refers to those in which two or more substances are fused with each other and become a uniform solid phase as a whole. Examples of the substance forming the solid solution include metal monomers and metal oxides. Especially when it is suitable for the solid solution of the metal oxide of this embodiment, two or more kinds of metal atoms are arranged irregularly on the equivalent lattice point in the unit lattice in the oxide crystal structure. Specifically, it is preferable that ruthenium oxide, iridium oxide, and titanium oxide are mixed with each other. When viewed from the side of ruthenium oxide, the ruthenium atom is replaced by an iridium atom or a titanium atom, or both of them. Solution. The solid solution state is not particularly limited, and there may also be a local solid solution region. The size of the unit lattice in the crystalline structure changes slightly due to solid solution. The degree of this change can be confirmed, for example, by measuring the powder X-ray diffraction without changing the diffraction pattern due to the crystal structure, but changing the peak position due to the size of the unit lattice. In the catalyst layer of this embodiment, the content ratio of the ruthenium element, the iridium element, and the titanium element is preferably 1 mole with respect to the ruthenium element, 0.06 to 3 mole with the iridium element, and 0.2 to 0.2 with the titanium element. 8 mol; more preferably 1 mol with respect to ruthenium, 0.2 to 3 mol with iridium, and 0.2 to 8 mol with titanium; further preferably 1 mol with ruthenium, 0.3 with iridium ～ 2 mol, and the titanium element is 0.2-6 mol; especially preferred is 1 mol to the ruthenium element, iridium is 0.5-1.5 mol, and the titanium element is 0.2-3 mol. By setting the content ratio of the three elements to the above range, the long-term durability of the electrode for electrolysis tends to be further improved. Iridium, ruthenium, and titanium may be contained in the catalyst layer in a form other than an oxide, for example, as a metal element. The catalyst layer of this embodiment contains the first transition metal element together with the above-mentioned ruthenium element, iridium element, and titanium element. The existence form of the first transition metal element is not particularly limited, and as long as it is contained in the catalyst layer, it may be, for example, an oxide form, a simple metal substance, or an alloy. In this embodiment, from the viewpoint of durability of the catalyst layer, the first transition metal element is preferably a solid solution with a solid solution of ruthenium oxide, iridium oxide, and titanium oxide. The formation of such a solid solution can be confirmed by XRD (X-ray Diffraction), for example. The solid solution can be formed by adjusting the firing temperature when the catalyst layer is formed, the amount of the first transition metal element added, and the like to an appropriate range. In this embodiment, from the viewpoint of considering both the voltage and durability of the catalyst layer, the first transition metal element preferably contains a metal element selected from the group consisting of vanadium, cobalt, copper, and zinc. The transition metal element is more preferably a vanadium element. The content ratio of the first transition metal element in the embodiment to all metal elements contained in the catalyst layer is preferably 10 mol% or more and 30 mol% or less, more preferably more than 10 mol% and 22.5 Molar% or less, more preferably 12 mol% or more and 20 mol% or less. In the case where the first transition metal element contains vanadium, the content ratio of vanadium with respect to all the metal elements contained in the catalyst layer is particularly preferably to satisfy the above range. The above-mentioned content ratio is mainly derived from the feed ratio of each element in the coating liquid prepared in the following preferred method for producing an electrode for electrolysis, and can be scanned by the following section STEM (Scanning Transmission Electron Microscope, scanning Transmission electron microscope (EDX) -EDX (Energy Dispersive X-Ray Analysis) or depth direction analysis using X-ray photoelectron spectroscopy (XPS) to confirm. When the content ratio of the first transition metal element is 10 mol% or more, there is a tendency that the overvoltage or electrolytic voltage generated by chlorine can be reduced from the initial stage of electrolysis. When the content ratio of the first transition metal element is 30 mol% or less, the durability of the ruthenium oxide tends to be sufficiently ensured. The content ratio of the first transition metal element contained in the catalyst layer in this embodiment to the 1 mol of the ruthenium element is preferably 0.3 mol or more and less than 2 mol, more preferably 0.5 mol or more and It is less than 2 moles, more preferably 0.5 moles or more and less than 1.8 moles. When the first transition metal element contains vanadium, it is particularly preferred that the content ratio of vanadium to the 1 mol of the ruthenium element contained in the catalyst layer satisfies the above range. The above-mentioned content ratio is mainly derived from the feed ratio of each element in the coating liquid prepared in the following preferred method for producing an electrode for electrolysis, and can be obtained by using the following section STEM-EDX or X-ray photoelectron It was confirmed by the depth direction analysis of the spectroscopic method (XPS). When the content ratio of the first transition metal element is 0.3 mol or more with respect to 1 mol of the ruthenium element, there is a tendency that the overvoltage or electrolytic voltage of chlorine can be reduced from the initial stage of electrolysis, and It is possible to sufficiently increase the following D value which is an index of the electric double layer capacitor. When it is less than 2 moles, the durability of the ruthenium oxide tends to be sufficiently ensured. The content ratio of the first transition metal element contained in the catalyst layer in this embodiment to the above-mentioned titanium element is 1 mol or more and less than 3.4 mol, preferably 0.25 mol or more and less than 2.6 Mol. In the case where the first transition metal element contains vanadium, it is particularly preferred that the content ratio of vanadium to the titanium element contained in the catalyst layer is 1 mol to satisfy the above range. The above-mentioned content ratio is mainly derived from the feed ratio of each element in the coating liquid prepared in the following preferred method for producing an electrode for electrolysis, and can be obtained by using the following section STEM-EDX or X-ray photoelectron It was confirmed by the depth direction analysis of the spectroscopic method (XPS). When the content ratio of the first transition metal element is 0.25 mol or more relative to 1 mol of the titanium element, there is a tendency that the overvoltage or electrolytic voltage of chlorine can be reduced from the initial stage of electrolysis, and It is possible to sufficiently increase the following D value which is an index of the electric double layer capacitor. When it is less than 3.4 mol, the durability of the ruthenium oxide tends to be sufficiently ensured. The element ratio (molar ratio) of V and Ti in the catalyst layer in the electrode for electrolysis can be confirmed by, for example, cross-sectional STEM-EDX or depth-direction analysis using X-ray photoelectron spectroscopy (XPS). For example, the following method is shown below: The elemental ratio of V to Ti in the catalyst layer containing ruthenium, iridium, titanium, and vanadium as the first transition metal element is determined by quantitative analysis in the XPS depth direction (Mo Ear ratio). Here, a Ti substrate is used as the conductive substrate. The XPS measurement conditions can be set as follows. Device: PHI5000VersaProbeII manufactured by ULVAC-PHI Company; Excitation source: Monochromatic AlKα (15 kV × 0.3 mA); Analysis size: about 200 μm f ; Photoelectron extraction angle: 45 °; PassEnergy: 46.95 eV (narrow Scan (Narrow scan) The Ar ⁺ sputtering conditions can be set as follows. Acceleration voltage: 2 kV; Scanning field range: 2 mm square; Zalar rotation. Regarding the calculation method of the concentration, the optical energy levels of the photoelectron peaks used for the quantification of Ru, Ir, Ti, and V are Ru3d, Ir4f, Ti2p, and V2p3 / 2. Since Ru3p3 / 2 overlaps Ti2p and Ti3s overlaps Ir4f, quantification can be performed in the following order. (1) Use the analysis software "MaltiPak" attached to the device to determine the area intensity of the peaks of Ru3d, Ir4f (including Ti3s), Ti2p (including Ru3p3 / 2), and V2p3 / 2 (each below) for each sputtering time (each depth). , Peak area intensity). (2) The peak area intensity of Ru3p3 / 2 was calculated based on the peak area intensity of Ru3d. The calculation was performed using the ratio of the corrected relative sensitivity factor (Corrected RSF) of MaltiPak (the relative sensitivity factor corrected according to the value of the general energy). The peak area intensity of only Ti2p was calculated by subtracting the peak area intensity of Ru3p3 / 2 from the peak area intensity of Ti2p containing Ru3p3 / 2. (3) Calculate the peak area intensity of Ti3s based on the corrected peak area intensity of Ti2p and use the ratio of the corrected relative sensitivity factor (Corrected RSF). The peak area intensity of only Ir4f was calculated by subtracting the peak area intensity of Ti3s from the peak area intensity of Ir4f containing Ti3s. The measured value of the element ratio (Molar ratio) of V and Ti in the catalyst layer obtained by quantitative analysis in the depth direction of XPS is based on the following calculation formula and is set to the ratio of the following two values, that is, cumulative detection The peak area intensity of V2p3 / 2 at each depth within the depth range of the catalyst layer of V is divided by the value obtained by the corrected relative sensitivity factor of V2p3 / 2, and the peak area intensity of Ti2p at each depth is summed. Divided by the corrected relative sensitivity factor (Corrected RSF) of Ti2p. Regarding the depth range of the catalyst layer that accumulates the peak area intensity of each element, for example, when the catalyst layer is a single layer, it is set to a depth range from the outermost surface to the time when a signal originating from Ti of the Ti substrate is detected. . Here, when the catalyst layer is multi-layer, the layers other than the catalyst layer directly formed on the surface of the Ti substrate are set to the depth range of each catalyst layer, and the layer directly formed on the surface of the Ti substrate is set. The catalyst layer is set to a depth range until a signal of Ti originating from the Ti substrate starts to be detected. [Number 1] Fig. 2 shows the actual measurement of V / Ti obtained from the following four samples a to d with different element ratios (molar ratios) of V and Ti using the above measurement method and XPS depth analysis. The results were plotted against the feed V / Ti value in the coating solution. (Sample a) The electrode for electrolysis with a V / Ti feed ratio of 0.11 is prepared by coating the elements (mole ratio) of ruthenium, iridium, titanium, and vanadium to 23.75: 23.75: 47.5: 5, respectively. An electrode for electrolysis obtained by the same method as in Example 1 described below except that the cloth liquid a was applied to a conductive substrate. (Sample b) The electrode for electrolysis with a V / Ti feed ratio of 0.22 is a coating prepared by adjusting the element ratio (mole ratio) of ruthenium, iridium, titanium, and vanadium to 22.5: 22.5: 45: 10, respectively. The electrode for electrolysis obtained by the same method as in Example 1 except that the cloth liquid b was applied to a conductive substrate. (Sample c) An electrode for electrolysis having a V / Ti feed ratio of 0.35 was obtained by the same method as in Example 1 described below. (Sample d) An electrode for electrolysis having a V / Ti feed ratio of 1.13 was obtained by the same method as in Example 3 described below. As shown in Figure 2, the measured value of V / Ti shows a positive correlation with the feed value, so the V in the catalyst layer containing ruthenium, iridium, titanium, and vanadium can be obtained from the calibration curve. Elemental ratio to Ti (Molar ratio). When the composition contained in the catalyst layer is changed, a calibration curve of the measured value and the fed value of V / Ti is prepared by the same method, so that the V and Ti elements in the catalyst layer can be obtained. Ratio (Morle ratio). Furthermore, in the electrode for electrolysis of this embodiment, the catalyst layer may include only one layer, or may have a multilayer structure of two or more layers. In the case of a multilayer structure, as long as the content ratio of the above-mentioned first transition metal element to the above-mentioned titanium element 1 mol in at least one of the layers is 0.25 mol or more and less than 3.4 mol, other layers also It may be one that does not satisfy the content ratio. The electrode for electrolysis of this embodiment is characterized in that a D value that is an index of an electric double-layer capacitor is 120 C / m ² or more and 420 C / m ² or less. Moreover, it is more preferably 120 C / m ² or more and 380 C / m ² or less, and still more preferably 150 C / m ² or more and 360 C / m ² or less. When the D value is 120 C / m ² or more, the generation of chlorine overvoltage can be suppressed, and the electrolytic voltage can be reduced. Furthermore, the durability of the ruthenium oxide can be maintained by being 420 C / m ² or less. The D value used as the index of the electric double-layer capacitor here is a value calculated by using the concept of the electric double-layer capacitor, and it is considered that the larger the surface area of the electrode (that is, the specific surface area of the catalyst layer on the electrode), the The value becomes larger. In addition, for example, by adjusting the content of the first transition metal element to the above-mentioned preferable range, the D value can be set to the above-mentioned range. In particular, by increasing the content of the first transition metal element, the D value tends to increase. In addition, the D value tends to decrease by increasing the firing temperature (post-baking temperature) when the catalyst layer is formed. Specifically, the cyclic voltammetry method described in the following examples can be used, and the value of the electrolytic current density (A / m ² ) measured with respect to a certain scanning speed (V / sec) can be used. And figure it out. More specifically, the difference in current density inherent in each scanning speed (the difference between the current density during forward scanning and the current density during reverse scanning) is obtained, and the vertical axis is set to the current density difference and 0.3 as the scanning range. Multiplying V, the horizontal axis is set to the scanning speed to draw each data, and then the slope when linear approximation of each drawn curve is set to the D value. Here, the product of the current density difference and 0.3 V, which is the scanning range, is often directly proportional to the scanning speed, so the D value can be expressed by the following formula (a). By setting the value of D, which is an index of the electric double-layer capacitor, to the above range, it is possible to reduce the overvoltage in the initial stage of electrolysis without impairing the durability of the obtained electrode for electrolysis. D (C / m ² ) = [Difference in electrolytic current density (A / m ² ) × 0.3 (V)] ÷ [Scanning speed (V / sec)] (a) The catalyst layer in this embodiment contains a ruthenium element , Iridium, titanium, and the first transition metal element, and further set the content ratio of the first transition metal element to the titanium element in a specific range, thereby increasing the D value that is an index of the electric double-layer capacitor as an electrolysis The function of the catalyst is improved, which can reduce the overvoltage in the initial stage of electrolysis. The catalyst layer in this embodiment may contain only the ruthenium element, iridium element, titanium element, and first transition metal element described above as constituent elements, and may contain other metal elements in addition to these. Specific examples of other metal elements are not limited to the following, and examples thereof include elements selected from tantalum, niobium, tin, and platinum. Examples of the existence form of these other metal elements include the existence of the metal elements included in the oxide. In the case where the catalyst layer in this embodiment contains other metal elements, its content ratio is based on the molar ratio of other metal elements to all metal elements contained in the catalyst layer, and is preferably 20 mol% or less. More preferably, it is 10 mol% or less. The thickness of the catalyst layer in this embodiment is preferably 0.1 to 5 μm, and more preferably 0.5 to 3 μm. By setting the thickness of the catalyst layer to be equal to or more than the above-mentioned lower limit value, there is a tendency that the initial electrolytic performance can be sufficiently maintained. In addition, by setting the thickness of the catalyst layer to be equal to or less than the above-mentioned upper limit value, there is a tendency that an electrode for electrolysis excellent in economic efficiency can be obtained. The catalyst layer may include only one layer or two or more layers. In a case where the catalyst layer is two or more layers, at least one of them is the catalyst layer in the embodiment. When the catalyst layer is two or more layers, it is preferred that at least the outermost layer be the catalyst layer in this embodiment. It is also preferable to have two or more catalyst layers in this embodiment with the same composition or different compositions. That is, when the catalyst layer is more than two layers, the thickness of the catalyst layer in this embodiment is also as described above, preferably 0.1 to 5 μm, and more preferably 0.5 to 3 μm. (Manufacturing method of electrode for electrolysis) Next, an example of the manufacturing method of the electrode for electrolysis of this embodiment is demonstrated in detail. The electrode for electrolysis of this embodiment can be produced, for example, by forming a catalyst layer containing a ruthenium element, an iridium element, a titanium element, and a first transition metal element on a conductive substrate that has been subjected to the surface area increasing treatment described above. The formation of the catalyst layer is preferably performed by a thermal decomposition method. Regarding the manufacturing method using a thermal decomposition method, a coating liquid containing a mixture of a compound (precursor) containing the above-mentioned elements can be applied to a conductive substrate, and then the coating liquid can be baked in an oxygen-containing environment. The components are thermally decomposed to form a catalyst layer. According to this method, the number of steps of the previous manufacturing method can be used to manufacture the electrode for electrolysis with high productivity. Here, the term "thermal decomposition" means that a metal salt or the like that becomes a precursor is baked in an oxygen-containing environment to decompose it into a metal oxide or a metal and a gaseous substance. The obtained decomposition products can be controlled by preparing the types of metals contained in the precursor, the types of metal salts, and the environment in which thermal decomposition is carried out as raw materials. Generally in an oxidizing environment, a large amount of metal tends to easily form an oxide. In the industrial manufacturing process of the electrode for electrolysis, the thermal decomposition is usually performed in the air. In this embodiment, the range of the oxygen concentration during firing is not particularly limited, and it may be performed in the air. However, if necessary, air may be circulated in the baking furnace or oxygen may be supplied. As a preferred aspect of the method for manufacturing an electrode for electrolysis in this embodiment, it is preferable to have the following steps: preparing a coating solution containing a ruthenium compound, an iridium compound, a titanium compound, and a compound containing a first transition metal element; The coating solution is coated on at least one side of a conductive substrate to form a coating film; and the coating film is fired in an oxygen-containing environment to form a catalyst layer. In addition, the ruthenium compound, the iridium compound, the titanium compound, and the compound containing the first transition metal element are equivalent to the precursor containing the metal element contained in the catalyst layer in this embodiment. By the above method, an electrode for electrolysis having a uniform catalyst layer can be manufactured. Among the compounds contained in the coating liquid, the ruthenium compound, the iridium compound, and the titanium compound may be oxides, but they are not necessarily oxides. For example, a metal salt may be used. The metal salts are not limited to the following, and examples thereof include oxidation selected from chloride salts, nitrates, dinitrosodiammine complexes, nitroso nitrates, sulfates, acetates, and metal alkanoates. Any of the groups of things. The metal salt of the ruthenium compound is not limited to the following, and examples thereof include ruthenium chloride and ruthenium nitrate. The metal salt of the iridium compound is not limited to the following, and examples thereof include iridium chloride and iridium nitrate. The metal salt of the titanium compound is not limited to the following, and examples thereof include titanium tetrachloride. Among the compounds contained in the coating liquid, the compound containing the first transition metal element may be an oxide, but it is not necessarily an oxide. For example, one or more members selected from the group consisting of an oxo acid of vanadium and a salt thereof, a chloride of vanadium, and a nitrate of vanadium are preferable. The counter cation in the oxo acid salt is not limited to the following, and examples thereof include Na ⁺ , K ⁺ , and Ca ²⁺ . As specific examples of such a compound, examples of the oxo acid or a salt thereof include sodium metavanadate, sodium orthovanadate, and potassium orthovanadate; examples of the chloride include vanadium chloride; and examples of the nitrate Examples include vanadium nitrate. The above compounds are appropriately selected and used depending on the required metal element ratio in the catalyst layer. The coating liquid may further include a compound other than the compound included in the compound. The other compounds are not limited to the following, and examples thereof include metal compounds containing metal elements such as tantalum, niobium, tin, platinum, and rhodium; organic compounds containing metal elements such as tantalum, niobium, tin, platinum, and rhodium. The coating liquid is preferably a liquid composition obtained by dissolving or dispersing the compound group in an appropriate solvent. As a solvent of the coating liquid used here, it can be selected depending on the kind of the compound. For example, water; alcohols such as butanol and the like can be used. The total compound concentration in the coating liquid is not particularly limited, but from the viewpoint of appropriately controlling the thickness of the catalyst layer, it is preferably 10 to 150 g / L. The method for applying the coating liquid to the surface of the conductive substrate is not limited to the following. For example, the following methods can be used: an immersion method of dipping the conductive substrate in the coating liquid; A method for applying a coating liquid on the surface of a conductive substrate; a roller method in which a conductive substrate is passed through a sponge-shaped roller impregnated with a coating liquid; and a conductive substrate and a coating liquid are sprayed with opposite charges The electrostatic coating method. Among these coating methods, a roll method and an electrostatic coating method are preferred from the viewpoint of excellent industrial productivity. By these coating methods, a coating film of a coating liquid can be formed on at least one side of a conductive substrate. After applying the coating liquid to the conductive substrate, it is preferable to perform a step of drying the coating film as necessary. By this drying step, the coating film can be more firmly formed on the surface of the conductive substrate. The drying conditions can be appropriately selected depending on the composition of the coating liquid, the type of solvent, and the like. The drying step is preferably performed at a temperature of 10 to 90 ° C for 1 to 20 minutes. After a coating film of a coating liquid is formed on the surface of the conductive substrate, it is fired in an oxygen-containing environment. The firing temperature can be appropriately selected according to the composition of the coating liquid and the type of the solvent. The firing temperature is preferably 300 to 650 ° C. If the firing temperature is less than 300 ° C., the decomposition of the precursor such as the ruthenium compound becomes insufficient, and a catalyst layer containing ruthenium oxide or the like may not be obtained. If the firing temperature exceeds 650 ° C, the conductive substrate may be oxidized, and thus the adhesion between the catalyst layer and the substrate may decrease. In particular, when a substrate made of titanium is used as the conductive substrate, this tendency should be taken seriously. A longer roasting time is preferred. On the other hand, from the viewpoint of electrode productivity, it is preferable to adjust so that the firing time does not become excessively long. Taking these circumstances into consideration, the firing time for one time is preferably 5 to 60 minutes. If necessary, the steps of coating, drying, and firing the catalyst layer are repeated several times to form the catalyst layer to a desired thickness. After the formation of the catalyst layer, the stability of the catalyst layer which is extremely stable chemically, physically, and thermally can be further improved by further firing for a long time if necessary. As a condition of long-time baking, it is preferable to carry out at 400 to 650 ° C for about 30 minutes to 4 hours. The electrode for electrolysis of this embodiment has a low overvoltage even at the initial stage of electrolysis, and can achieve electrolysis with low voltage and low power consumption for a long period of time. Therefore, it can be used for various electrolysis. Particularly, it is preferably used as an anode for chlorine generation, and more preferably used as an anode for salt electrolysis by an ion exchange membrane method. (Electrolytic cell) The electrolytic cell of this embodiment includes the electrode for electrolysis of this embodiment. This electrolytic cell is the one whose initial voltage is reduced during electrolysis. Fig. 1 is a schematic cross-sectional view showing an example of an electrolytic cell according to this embodiment. The electrolytic cell 200 is provided with an electrolytic solution 210, a container 220 for containing the electrolytic solution 210, an anode 230 and a cathode 240 immersed in the electrolytic solution 210, an ion exchange membrane 250, and a means for connecting the anode 230 and the cathode 240 to a power source Wiring 260. In the electrolytic cell 200, a space on the anode side separated by the ion exchange membrane 250 is referred to as an anode chamber, and a space on the cathode side is referred to as a cathode chamber. The electrolytic cell of this embodiment can be used for various electrolysis. Hereinafter, as a representative example, a case where it is used for the electrolysis of an alkali chloride aqueous solution will be described. As the electrolytic solution 210 supplied to the electrolytic cell of the present embodiment, for example, an aqueous sodium chloride solution (aqueous salt solution) such as a 2.5 to 5.5 equivalent (N) sodium chloride solution and an aqueous potassium chloride solution can be used in the anode chamber, respectively. In the cathode chamber, a dilute aqueous alkali hydroxide solution (for example, an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, etc.) or water is used. As the anode 230, the electrode for electrolysis of this embodiment is used. As the ion exchange membrane 250, for example, a fluororesin membrane having an ion exchange group can be used. Specific examples thereof include "Aciplex" (registered trademark) F6801 (manufactured by Asahi Kasei Corporation). The cathode 240 may be a cathode for hydrogen generation, and an electrode or the like coated with a catalyst on a conductive substrate. As the cathode, a known one can be used. Specifically, for example, a cathode coated with nickel, nickel oxide, an alloy of nickel and tin, a combination of activated carbon and an oxide, ruthenium oxide, platinum, or the like is coated on a nickel substrate. ; A ruthenium oxide-coated cathode is formed on a nickel metal wire mesh substrate. The configuration of the electrolytic cell in this embodiment is not particularly limited, and may be a unipolar type or a bipolar type. The material constituting the electrolytic cell is not particularly limited. For example, as the material of the anode chamber, titanium having resistance to alkali chloride and chlorine is preferable; as the material of the cathode chamber, it is preferable to have alkali hydroxide and hydrogen. Resistant to nickel. The electrode (anode 230) for electrolysis in this embodiment can be arranged with an appropriate interval between the electrode and the ion exchange membrane 250, and can be used without any problem even if it is arranged in contact with the ion exchange membrane 250. The cathode 240 can also be arranged with an appropriate distance from the ion-exchange membrane 250, and even if it is a contact-type electrolytic cell (zero-pitch type electrolytic cell) without a gap from the ion-exchange membrane 250, Use it questionably. There are no particular restrictions on the electrolysis conditions of the electrolytic cell of this embodiment, and it can be operated under known conditions. For example, it is preferable to perform the electrolysis by adjusting the electrolysis temperature to 50 to 120 ° C and the current density to 0.5 to 10 kA / m ² . The electrode for electrolysis of this embodiment can reduce the electrolysis voltage when the salt is electrolyzed. Therefore, according to the electrolytic cell of this embodiment provided with the electrode for electrolysis, the power consumption required for salt electrolysis can be reduced. Furthermore, the electrode for electrolysis according to this embodiment has a catalyst layer that is extremely stable chemically, physically, and thermally, and therefore has excellent long-term durability. Therefore, according to the electrolytic cell of this embodiment provided with the electrode for electrolysis, the catalyst activity of the electrode can be maintained high for a long period of time, and high-purity chlorine can be stably produced. [Examples] Hereinafter, this embodiment will be described in more detail based on examples. This embodiment is not limited to these examples. First, each evaluation method in an Example and a comparative example is shown below. (Ion Exchange Membrane Salt Electrolysis Test) As an electrolytic cell, an electrolytic cell including an anode cell having an anode chamber and a cathode cell having a cathode chamber was prepared. The electrode for electrolysis prepared in each example and comparative example was cut into a specific size (95 × 110 mm = 0.01045 m ² ), the obtained electrode was used as a test electrode, and the test electrode was mounted by welding. Used as the anode in the wall of the anode compartment of the anode cell. As the cathode, a catalyst coated with ruthenium oxide on a nickel wire mesh substrate was used. First, a metal nickel extension base material as a current collector is cut out in the same size as the anode and welded to the wall portion of the cathode chamber of the cathode cell. Then, a buffer pad with a braided nickel wire is mounted, and the cathode is arranged on the buffer pad. . As the gasket, a rubber gasket made of EPDM (ethylene propylene diene) was used, and an ion exchange membrane was interposed between the anode cell and the cathode cell. As this ion exchange membrane, a cation exchange membrane "Aciplex" (registered trademark) F6801 (manufactured by Asahi Kasei Corporation) for salt electrolysis was used. In order to measure the overvoltage of chlorine, using a polytetrafluoroethylene thread, platinum was removed by covering a portion of approximately 1 mm from the front end of the platinum wire covered with PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer). The exposed person is connected and fixed to the surface of the anode opposite to the ion exchange membrane to serve as a reference electrode. In the electrolytic test, the generated chlorine gas became a saturated environment, so the reference electrode showed a potential for chlorine generation. Therefore, the voltage obtained by subtracting the potential of the reference electrode from the potential of the anode was used as the chlorine overvoltage of the anode. On the other hand, as the electrolytic voltage, the potential difference between the cathode and the anode was measured. In order to measure the initial electrolytic performance of the anode, the overvoltage and electrolytic voltage were measured at 7 days after the start of electrolysis. The electrolysis conditions were performed at a current density of 6 kA / m ² , a saltwater concentration of 205 g / L in the anode cell, a NaOH concentration of 32% by mass in the cathode cell, and a temperature of 90 ° C. As the rectifier for electrolysis, "PAD36-100LA" (manufactured by Kikusui Electronics Co., Ltd.) was used. (Accelerated test) As a test electrode to be mounted on the anode cell, a cell cut into a size of 58 × 48 mm = 0.002748 m ² was used. Except that, the same electrolytic cell as the above-mentioned ion exchange membrane method salt electrolysis test was used. The electrolytic conditions were performed at a current density of 6 kA / m ² , a brine concentration of 205 g / L in the anode tank, a NaOH concentration of 32% by mass in the cathode tank, and a temperature of 90 ° C. In order to confirm the durability of the test electrode, a series of operations including electrolysis stop, water washing in the electrolytic cell (10 minutes), and start of electrolysis were performed once every 7 days. Chlorine overvoltage (anode) was measured every 7 days after the start of electrolysis. Overvoltage). Furthermore, the values of Ru and Ir residues in the catalyst layer of the test electrode after electrolysis were calculated using the values obtained by fluorescent X-ray measurement (XRF) of each metal component before and after electrolysis (100 × before electrolysis). Content / content after electrolysis;%). As the XRF measurement device, Niton XL3t-800 or Niton XL3t-800s (trade name, manufactured by Thermo Scientific) was used. (D value which becomes an index of an electric double layer capacitor) The test electrode was cut into a size of 30 × 30 mm = 0.0009 m ² , and was fixed to the electrolytic cell with a screw made of titanium. The opposite electrode system was a platinum mesh, and was subjected to an electrolytic current density of 1 kA / m ² , 2 kA / m ^2, and 3 kA / m ² for 5 minutes each in an aqueous NaCl solution at a temperature of 85 to 90 ° C. and a salt concentration of 205 g / L. Electrolysis was performed at 4 kA / m ² for 30 minutes to generate chlorine at the test anode. After the above electrolysis, Ag / AgCl was used as a reference electrode, the applied potential was set to a range of 0 V to 0.3 V, and the scanning speed was set to 10 mV / sec, 30 mV / sec, 50 mV / sec, 80 mV / The cyclic voltammogram was measured in seconds, 100 mV / second, and 150 mV / second, and the electrolytic current density at 0.15 V was measured at the center of the applied potential range when scanning from 0 V to the positive direction of 0.3 V, and from 0.3 V The center of the applied potential range when scanning in the opposite direction of 0 V is the electrolytic current density at 0.15 V, and the difference between the two electrolytic current densities is obtained at each of the above scanning speeds. The difference between the electrolytic current density obtained at each scanning speed and the product of 0.3 V, which is the scanning range, is approximately proportional to the scanning speed, and the slope is calculated as the D value (C / m ^{2) which is an} indicator of the electric double layer capacitance. ). [Example 1] As the conductive substrate, a titanium extended substrate having a large mesh size (LW) of 6 mm, a small mesh size (SW) of 3 mm, and a plate thickness of 1.0 mm was used. This stretched substrate was baked in the air at 540 ° C for 4 hours, and after forming an oxide film on the surface, it was subjected to an acid treatment in 25% by mass of sulfuric acid at 85 ° C for 4 hours, and then finely set on the surface of the conductive substrate. Pre-bumping. Next, the ruthenium nitrate aqueous solution (manufactured by Furiya Metal Co., Ltd., with a ruthenium concentration of 100 g / L) was cooled with dry ice so that the element ratios (molar ratios) of ruthenium, iridium, titanium, and vanadium were 21.25: 21.25: 42.5: 15. After stirring to 5 ° C or lower, titanium tetrachloride (manufactured by Wako Pure Chemical Industries, Ltd.) was added in small amounts, and then an iridium chloride aqueous solution (manufactured by Tanaka Precious Metals Co., Ltd.) was added in small amounts each time. ) And vanadium (III) chloride (manufactured by Kishida Chemical Co., Ltd.) to obtain a coating solution A1, which is an aqueous solution having a total metal concentration of 100 g / L. The coating liquid A1 is poured into a liquid receiving tank of the coating machine, and the EPDM sponge roller is rotated to suck up the coating liquid A1 and impregnate it. The PVC roller is arranged so as to contact the upper part of the sponge roller. . Then, the conductive substrate subjected to the pretreatment is applied between the EPDM sponge roller and the PVC roller. Immediately after coating, the above-mentioned coated conductive substrate was passed between two EPDM sponge rollers wound with a cloth to wipe the excess coating liquid. Thereafter, it was dried at 50 ° C for 10 minutes, and then calcined at 400 ° C for 10 minutes in the air. Regarding the above-mentioned cycle including roll coating, drying, and firing, the firing temperature was raised to 450 ° C, and the above-mentioned cycle was repeated three times, and finally, firing at 520 ° C for one hour was performed on the conductive substrate A dark brown catalyst layer was formed to prepare an electrode for electrolysis. [Comparative Example 1] A ruthenium chloride aqueous solution (manufactured by Tanaka Noble Metal Co., Ltd., with a ruthenium concentration of 100 g / L) was cooled with dry ice so that the element ratio (molar ratio) of ruthenium, iridium, and titanium became 25:25:50. After stirring to 5 ° C or lower, titanium tetrachloride (manufactured by Wako Pure Chemical Industries, Ltd.) was added in small amounts, and then an iridium chloride aqueous solution (manufactured by Tanaka Precious Metals Co., Ltd.) was added in small amounts each time. ) To obtain a coating solution B1 which is an aqueous solution having a total metal concentration of 100 g / L. This coating liquid B1 was used, and regarding the cycle including roll coating, drying, and firing, the first firing temperature was set to 440 ° C, the temperature was then raised to 475 ° C, the above-mentioned cycle was repeated three times, and finally 520 was further performed. An electrode for electrolysis was produced in the same manner as in Example 1 except that it was calcined at 1 ° C for 1 hour. [Example 2] A coating liquid A2 prepared so that the element ratio (mole ratio) of ruthenium, iridium, titanium, and vanadium becomes 25.45: 25.45: 30: 19.1 was used and applied to a conductive substrate, except that Other than that, an electrode for electrolysis was produced by the same method as in Example 1. [Example 3] A coating liquid A3 prepared so that the element ratio (mole ratio) of ruthenium, iridium, titanium, and vanadium becomes 28.75: 28.75: 20: 22.5 was used and applied to a conductive substrate, except that Other than that, an electrode for electrolysis was produced by the same method as in Example 1. [Example 4] A coating liquid A4 prepared so that the element ratio (mole ratio) of ruthenium, iridium, titanium, and vanadium becomes 32.05: 32.05: 10: 25.9 was used and applied to a conductive substrate, except that Other than that, an electrode for electrolysis was produced by the same method as in Example 1. [Example 5] A coating liquid A5 prepared so that the element ratio (mole ratio) of ruthenium, iridium, titanium, and vanadium becomes 17.5: 17.5: 35: 30 was applied to a conductive substrate, except that Other than that, an electrode for electrolysis was produced by the same method as in Example 1. The composition of the electrode for electrolysis (metal composition of the coating liquid used to form the catalyst layer) prepared in Examples 1 to 5 and Comparative Example 1 and the measured D which becomes the index of the electric double layer capacitor The values are shown in Table 1. The unit "mol%" in the table means the mole percentage (feed ratio) with respect to all metal elements included in the formed catalyst layer. The value of the first transition metal element / Ru and the value of the first transition metal element / Ti are values calculated from the feed ratio. [Table 1] [Ion exchange membrane method salt electrolysis test] An ion exchange membrane method salt electrolysis test was performed using the electrodes for electrolysis prepared in Examples 1 to 5 and Comparative Example 1, respectively. The results are shown in Table 2. [Table 2] The electrolytic voltage at a current density of 6 kA / m ² was 2.94 V in Examples 1 and 2, 2.92 V in Examples 3 and 4, respectively, and 2.91 V in Example 5, which was the same as in Comparative Example 1. Compared with 2.99 V, they all show extremely low values. The anode overvoltage was 0.032 V in Example 1, 0.034 V in Example 2, 0.032 V in Examples 3 and 4, and 0.031 V in Example 5, respectively. Compared with 0.057 V in Example 1, all showed lower values. [Example 6] A coating liquid A6 prepared so that the element ratios (molar ratios) of ruthenium, iridium, titanium, and vanadium became 37: 33.35: 11.15: 18.5 was applied to a conductive substrate, and Regarding the cycle including roll coating, drying, and firing, the first firing temperature was set to 310 ° C, followed by increasing the temperature to 520 ° C, and then the above-mentioned cycle was repeated 3 times, and then the firing at 520 ° C for 1 hour was performed. Other than that, an electrode for electrolysis was produced by the same method as in Example 1. [Example 7] A coating liquid A7 prepared so that the element ratio (mole ratio) of ruthenium, iridium, titanium, and vanadium becomes 31.25: 28.1: 9.4: 31.25 was used and applied to a conductive substrate, and Regarding the cycle including roll coating, drying, and firing, the first firing temperature was set to 380 ° C, followed by increasing the temperature to 450 ° C, and then the above-mentioned cycle was repeated 3 times, and then the firing at 450 ° C for 1 hour was performed. Other than that, an electrode for electrolysis was produced by the same method as in Example 1. [Example 8] An aqueous ruthenium chloride solution (manufactured by Tanaka Noble Metal Co., Ltd. with a ruthenium concentration of 100 g / L) was used instead of an aqueous ruthenium nitrate solution. The element ratio (molar ratio) of ruthenium, iridium, titanium, and vanadium was 19.6: The coating liquid A8 prepared in the manner of 20.2: 47.09: 13.11 is applied to a conductive substrate, and the cycle including the roll coating, drying, and baking is performed at the first to eighth baking temperatures. An electrode for electrolysis was produced by the same method as in Example 1 except that the baking was performed at 393 ° C for one hour at 485 ° C. [Example 9] An aqueous ruthenium chloride solution (manufactured by Tanaka Noble Metal Co., Ltd., with a ruthenium concentration of 100 g / L) was used instead of an aqueous ruthenium nitrate solution, and cobalt (II) chloride hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of chlorine. Vanadium (III), and a coating liquid A9 prepared by adjusting the element ratio (mole ratio) of ruthenium, iridium, titanium, and cobalt to 50: 3: 30: 17, and applied to a conductive substrate And, for the cycle including roll coating, drying and baking, the first baking temperature was set to 440 ° C, followed by increasing the temperature to 475 ° C, and then the above-mentioned cycle was repeated 3 times, and finally, it was further performed at 520 ° C for 1 hour. Except for firing, an electrode for electrolysis was produced in the same manner as in Example 1. [Example 10] Copper (II) nitrate trihydrate (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of vanadium (III) chloride, and the element ratio (molar ratio) using ruthenium, iridium, titanium, and copper was 32.05: Except that the coating liquid A10 prepared in the manner of 32.05: 10: 25.9 was applied to a conductive substrate, an electrode for electrolysis was produced by the same method as in Example 1. [Example 11] Zinc (II) nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of vanadium (III) chloride, and the element ratio (molar ratio) using ruthenium, iridium, titanium, and zinc was 32.05: Except that the coating liquid A11 prepared in the manner of 32.05: 10: 25.9 was applied to a conductive substrate, an electrode for electrolysis was produced by the same method as in Example 1. [Comparative Example 2] A coating liquid B2 prepared so that the element ratio (mole ratio) of ruthenium, iridium, titanium, and vanadium becomes 20: 18: 60: 2 was applied to a conductive substrate, and An aqueous ruthenium chloride solution (manufactured by Tanaka Precious Metals Co., Ltd., with a concentration of 100 g / L) was used for the preparation of the coating liquid, and the first firing temperature was set to 450 for the cycle including roll coating, drying, and firing. The above-mentioned cycle was repeated three times at 450 ° C and then baked at 450 ° C for one hour, and an electrode for electrolysis was produced in the same manner as in Example 1. [Comparative Example 3] A coating liquid B3 prepared so that the element ratios (molar ratios) of ruthenium, iridium, titanium, and vanadium were 22.7: 20.5: 34.1: 22.7 was applied to a conductive substrate, and Regarding the cycle including roll coating, drying, and firing, the first firing temperature was set to 380 ° C, and then the above-mentioned cycle was repeated 3 times at 380 ° C, and finally the firing at 590 ° C for 1 hour was performed. Other than that, an electrode for electrolysis was produced by the same method as in Example 1. [Comparative Example 4] A coating liquid B4 prepared so that the element ratio (mole ratio) of ruthenium, iridium, titanium, and vanadium becomes 28.6: 25.7: 42.8: 2.9 is applied to a conductive substrate, and Regarding the cycle including roll coating, drying and firing, the first firing temperature was set to 450 ° C, followed by increasing the temperature to 520 ° C, and then the above-mentioned cycle was repeated 3 times, and then the firing at 520 ° C was performed for 1 hour. Other than that, an electrode for electrolysis was produced by the same method as in Example 1. [Comparative Example 5] A coating liquid B5 prepared by applying an element ratio (molar ratio) of ruthenium, iridium, titanium, and vanadium to 18.5: 16.7: 55.55: 9.25 was applied to a conductive substrate, and An aqueous ruthenium chloride solution (manufactured by Tanaka Noble Metal Co., Ltd., with a concentration of 100 g / L) was used for the preparation of the coating solution, and the first baking temperature was set to 310 for a cycle including roll coating, drying, and baking. The temperature was raised to 380 ° C, followed by repeating the above-mentioned cycle three times, and finally firing at 590 ° C for one hour. Except that, an electrode for electrolysis was produced in the same manner as in Example 1. [Comparative Example 6] Manganese nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of vanadium (III) chloride in Example 1, and the element ratio (molar ratio) of ruthenium, iridium, titanium, and manganese was 21.25: 21.25: An electrolytic electrode was prepared by the same method as in Example 1 except that the coating liquid B6 prepared in the manner of 42.5: 15 was applied to a conductive substrate. [Comparative Example 7] Zinc nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of vanadium (III) chloride in Example 1, and the element ratio (molar ratio) of ruthenium, iridium, titanium, and zinc was 21.25: 21.25: An electrolytic electrode was prepared by the same method as in Example 1 except that the coating liquid B7 prepared in the manner of 42.5: 15 was applied to a conductive substrate. [Comparative Example 8] Palladium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) was used instead of vanadium (III) chloride in Example 1, and the element ratio (molar ratio) of ruthenium, iridium, titanium, and palladium was 16.9: 15.4: The coating liquid B8 prepared in the manner of 50.8: 16.9 is applied to a conductive substrate. Regarding the cycle including roll coating, drying, and baking, the first baking temperature is set to 450 ° C, and the second temperature is raised to The above-mentioned cycle was repeated three times at 520 ° C, and finally, baking was further performed at 590 ° C for one hour, and an electrode for electrolysis was produced by the same method as in Example 1. [Comparative Example 9] A coating liquid B9 prepared so that the element ratio (mole ratio) of ruthenium, titanium, and vanadium becomes 40:40:20 was applied to a conductive substrate, and the coating liquid was applied to the conductive liquid. For the preparation, an aqueous ruthenium chloride solution (manufactured by Tanaka Noble Metal Co., Ltd., with a ruthenium concentration of 100 g / L) was used. Regarding the cycle including roll coating, drying, and baking, the first baking temperature was set to 440 ° C, and the second temperature was raised The above-mentioned cycle was repeated three times to 475 ° C, and finally, baking was further performed at 520 ° C for one hour, and an electrode for electrolysis was produced by the same method as in Example 1. The configurations of the electrodes for electrolysis (metal composition of the coating liquid used to form the catalyst layer) prepared in Examples 6 to 11 and Comparative Examples 2 to 9 were respectively measured to be electric double-layer capacitors. The D value of the index is shown in Table 3. The unit "mol%" in the table means the mole percentage (feed ratio) with respect to all metal elements included in the formed catalyst layer. The value of the first transition metal element / Ru and the value of the first transition metal element / Ti are values calculated from the feed ratio. [table 3] [Acceleration Test] The acceleration tests were performed using the electrodes for electrolysis prepared in Examples 1 to 11 and Comparative Examples 1 to 9, respectively. The results are shown in Table 4. In addition, since the durability of Comparative Example 9 ruthenium was low, it was an evaluation result at the time when the test was suspended after 14 days. [Table 4] The results of the 21-day accelerated test were as follows. The anode overvoltages of the electrode systems for electrolysis in Examples 1 to 11 were 0.030 to 0.045 V one day after the test was started, and the anode overvoltages were 0.030 to 0.039 V after 21 days. In contrast, the anode overvoltages of the electrolytic electrode system tests of Comparative Examples 1 to 8 were 0.042 to 0.110 V one day after the test was started, and the anode overvoltages were 0.043 to 0.093 V 21 days later. As described above, it was confirmed that, compared with the comparative example, the example can achieve electrolysis with low voltage and low power consumption in the initial stage of electrolysis and for a long period of time. In addition, it was confirmed that, compared with Comparative Example 9 in which the anode overvoltage was the same, in Examples 1 to 11, even after 21 days from the start of the test, the residual rates of Ru and Ir were higher, and one side The anode overvoltage is kept low, and the durability during long-term electrolysis is also sufficient. This application is based on a Japanese patent application filed on November 22, 2016 (Japanese Patent Application No. 2016-227066), the contents of which are incorporated herein by reference. [Industrial Applicability] The electrode for electrolysis of the present invention exhibits low overvoltage generated by chlorine, and can achieve electrolysis with low voltage and low power consumption. Therefore, it can be preferably used in the field of salt electrolysis. It is particularly useful as an anode for salt electrolysis by the ion-exchange membrane method, and can continuously produce high-purity chlorine gas with low oxygen concentration with low voltage and low power consumption for a long period of time.

200‧‧‧ electrolytic cell for electrolysis

210‧‧‧ Electrolyte

220‧‧‧container

230‧‧‧Anode (electrode for electrolysis)

240‧‧‧ cathode

250‧‧‧ ion exchange membrane

260‧‧‧Wiring

FIG. 1 is a schematic cross-sectional view of an example of an electrolytic cell according to this embodiment. FIG. 2 shows V / Ti obtained by analyzing the depth direction of XPS (X-ray Photoelectron Spectroscopy) for 4 samples with different element ratios (molar ratios) of V and Ti. A graph of the actual measured value and the feed V / Ti value in the coating solution, and the results obtained by linear approximation.

Claims (9)

An electrode for electrolysis, comprising: a conductive substrate, and a catalyst layer formed on a surface of the conductive substrate, wherein the catalyst layer includes a ruthenium element, an iridium element, a titanium element, and a member selected from the group consisting of Sc At least one first transition metal element in the group consisting of V, Cr, Fe, Co, Ni, Cu and Zn, and the first transition metal element contained in the catalyst layer contains 1 mole of the titanium element. The ratio is 0.25 mol% or more and less than 3.4 mol%. The D value of the above-mentioned electrode for electrolysis to be an electric double-layer capacitor is 120 C / m ² or more and 420 C / m ² or less. The electrode for electrolysis according to claim 1, wherein the first transition metal element and the solid solution of ruthenium oxide, iridium oxide, and titanium oxide form a solid solution. The electrode for electrolysis according to claim 1 or 2, wherein the first transition metal element includes at least one metal element selected from the group consisting of vanadium, cobalt, copper, and zinc. The electrode for electrolysis according to any one of claims 1 to 3, wherein the first transition metal element includes a vanadium element. The electrode for electrolysis according to any one of claims 1 to 4, wherein the content ratio of the first transition metal element to all the metal elements contained in the catalyst layer is 10 mol% or more and 30 mol% or less. The electrolytic electrode according to any one of claims 1 to 5, wherein a content ratio of the first transition metal element contained in the catalyst layer to 1 mol of the ruthenium element is 0.3 mol or more and less than 2 mol. ear. The electrode for electrolysis according to any one of claims 1 to 6, wherein the above-mentioned D value is 120 C / m ² or more and 380 C / m ² or less. A method for manufacturing an electrode for electrolysis, which is a method for manufacturing the electrode for electrolysis according to any one of claims 1 to 7, which has the following steps: preparing a ruthenium compound, an iridium compound, a titanium compound, and A coating liquid of a compound of a transition metal element; coating the coating liquid on at least one side of the conductive substrate to form a coating film; and firing the coating film in an oxygen-containing environment to form the catalyst layer . An electrolytic cell provided with the electrode for electrolysis according to any one of claims 1 to 7.