Title of invention: Electrode for electrolysis
technical field
[One]
Cross-Citation with Related Applications
[2]
This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0170677 dated December 19, 2019, and all contents disclosed in the literature of the Korean patent application are incorporated as a part of this specification.
[3]
technical field
[4]
The present invention relates to an electrode for electrolysis capable of improving overvoltage and a method for manufacturing the same.
background
[5]
A technique for producing hydroxide, hydrogen and chlorine by electrolyzing inexpensive brine such as seawater is widely known. This electrolysis process is usually called a chlor-alkali process, and it can be said that it is a process whose performance and reliability of technology have been proven through commercial operation for several decades.
[6]
For the electrolysis of brine, an ion exchange membrane is installed inside the electrolyzer to divide the electrolyzer into a cation chamber and an anion chamber, and the ion exchange membrane method, which uses brine as an electrolyte to obtain chlorine gas from the anode and hydrogen and caustic soda from the cathode, is currently the most widely used method being used.
[7]
On the other hand, the electrolysis process of brine is made through a reaction as shown in the following electrochemical reaction formula.
[8]
Anode reaction: 2Cl - → Cl 2 + 2e - (E 0 = +1.36 V)
[9]
Cathode reaction: 2H 2 O + 2e - → 2OH - + H 2 (E 0 = -0.83 V)
[10]
Overall reaction: 2Cl - + 2H 2 O → 2OH - + Cl 2 + H 2 (E 0 = -2.19 V)
[11]
[12]
In carrying out the electrolysis of brine, the electrolysis voltage should consider all of the voltages required for the electrolysis of the brine in theory, the overvoltage of the anode, the overvoltage of the cathode, the voltage due to the resistance of the ion exchange membrane, and the voltage due to the distance between the anode and the cathode. Among these voltages, the overvoltage by the electrode is acting as an important variable.
[13]
Accordingly, a method for reducing the overvoltage of the electrode is being researched. For example, a noble metal-based electrode called DSA (Dimensionally Stable Anode) has been developed and used as an anode, and an excellent material with a low overvoltage and durability for the anode is also developed. this is being requested
[14]
Stainless steel or nickel was mainly used as the anode, and in particular, the over potential (η) in the electrolysis reaction is inversely proportional to the active surface area (A), so a woven mesh that can have a large active specific surface area. mesh) or an expanded mesh type of nickel was mainly used.
[15]
However, if the pore size of the nickel mesh is increased to increase the active specific surface area, it may be difficult to secure flatness in the substrate pretreatment process during the electrode manufacturing process, and problems may occur that the mesh pores may be clogged during the coating layer formation process. Even when the electrode is used for the electrolysis reaction, it may affect the mass transfer of the electrolyte and the desorption of hydrogen gas, so it is necessary to develop a nickel mesh that satisfies the appropriate conditions.
[16]
[17]
Prior art literature
[18]
(Patent Document 1) JP2003-277967A
[19]
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[20]
An object of the present invention is to optimize the wire thickness and mesh size of the metal substrate used for the electrode for electrolysis, to provide an electrode for electrolysis with improved overvoltage compared to the conventional electrode, and a method for manufacturing the same.
means of solving the problem
[21]
In order to solve the above problems, the present invention includes a metal substrate layer, and a coating layer containing ruthenium oxide and nitrogen, wherein the metal substrate layer has a mesh structure having a mesh size of 45 to 60 mesh, The individual wire thickness is 100 to 160 μm, and the nitrogen content in the coating layer provides an electrode for electrolysis of 20 to 60 mol% compared to ruthenium oxide.
Effects of the Invention
[22]
The electrode for electrolysis of the present invention has a large active specific surface area and less clogging of pores by the coating layer, thereby exhibiting a low overvoltage, and exhibiting excellent durability due to a small loss of the coating layer during the electrolysis process.
Modes for carrying out the invention
[23]
Hereinafter, the present invention will be described in more detail.
[24]
The terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor may properly define the concept of the term in order to best describe his invention. Based on the principle that there is, it should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention.
[25]
[26]
"Mesh" as a unit of mesh size described in the present invention is defined as the number of eyes of a mesh included within 1 inch, for example, 40 mesh refers to the size of a mesh structure having 40 eyes within 1 inch.
[27]
[28]
Electrode for electrolysis
[29]
The present invention includes a metal base layer, and a coating layer comprising ruthenium oxide and nitrogen, wherein the metal base layer has a mesh structure having a mesh size of 45 to 60 mesh, and an individual wire thickness of the mesh structure is 100 to 160 μm And, the nitrogen content in the coating layer provides an electrode for electrolysis of 20 to 60 mol% compared to ruthenium oxide.
[30]
[31]
In the case of the existing electrode for electrolysis, a metal substrate having a mesh size of 40 mesh was mainly used. However, when a mesh structure of 40 mesh is used as a metal substrate for an electrode for electrolysis, a sufficient level of active specific surface area cannot be provided, so it is relatively As a result, there was a problem that high overvoltage appeared. Accordingly, the inventors of the present invention invented an electrode for electrolysis that can improve the overvoltage by optimizing the structure of the metal substrate used for the electrode for electrolysis, and has excellent durability due to less detachment of the coating layer during electrolysis.
[32]
[33]
Specifically, the metal substrate of the electrode for electrolysis provided by the present invention has a mesh structure having a mesh size of 45 to 60 mesh, and the thickness of the individual wires constituting the mesh structure is 100 to 160 μm. More specifically, it is preferable that the mesh size is 50 to 60 mesh, and the thickness of the individual wire is 120 to 150 μm. When the mesh size of the metal substrate and the thickness of the individual wires are within the above-described ranges, the overvoltage is improved and the coating layer component is less dropped. In particular, when the thickness of the wire is thinner than the range of the present invention, flatness may not be maintained in the pretreatment process during the electrode manufacturing process, and physical durability may be weak, so that even a small impact may cause scratches. In addition, since the active area also decreases as the thickness of the wire decreases, there may be a problem in that the overvoltage increases compared to the conventional electrode. In addition, when the wire thickness is thicker than the range of the present invention, the coating layer may not be uniformly formed by the thick individual wires, the coating layer components may fall off more easily, and the dead volume between the wire and the membrane may decrease. This may cause a gas trap phenomenon.
[34]
[35]
The metal substrate may be nickel, titanium, tantalum, aluminum, hafnium, zirconium, molybdenum, tungsten, stainless steel, or an alloy thereof, of which nickel is preferable. In the electrode for electrolysis of the present invention, when such a type of metal substrate is used, it is possible to provide the electrode with superior durability and mechanical strength.
[36]
[37]
In the electrode for electrolysis of the present invention, the coating layer includes ruthenium oxide. The ruthenium oxide serves to provide the ruthenium element to the coating layer as an active material, and when ruthenium oxide is used for the coating layer of the electrode for electrolysis, the overvoltage phenomenon is improved, and the change in electrode performance over time is small, and thereafter, separate activation process can be minimized. The ruthenium oxide includes all kinds of oxides in which the ruthenium element and the oxygen atom are combined, and in particular, may be a dioxide or a tetraoxide.
[38]
[39]
In the electrode for electrolysis of the present invention, the coating layer contains nitrogen. The nitrogen originates from the amine-based additive included in the coating composition during the coating layer manufacturing process, and when the amine-based additive is added to the coating composition, the bonding force between the ruthenium elements included in the coating layer and other metal elements are included in the ruthenium element The electrode can be manufactured in a form more suitable for the reaction by improving the bonding force between the and the metal element, and controlling the oxidation state of the particles including the ruthenium element.
[40]
The nitrogen content in the coating layer may be 30 to 70 mol%, preferably 40 to 60 mol%, compared to ruthenium oxide, and when the nitrogen content is within the above-described range, the improvement in bonding strength between ruthenium elements can be maximized. In addition, in a range in which the nitrogen content is less than this, the effect by nitrogen is insignificant, and in a range larger than this, a problem in that nitrogen acts as an impurity in the coating layer may occur.
[41]
[42]
In the electrode for electrolysis of the present invention, the coating layer may further include cerium oxide, and the cerium oxide serves to provide a cerium element to the catalyst layer of the electrode for electrolysis. The cerium element provided by the cerium oxide improves the durability of the electrode for electrolysis, thereby minimizing loss of elemental ruthenium as an active material in the catalyst layer of the electrode for electrolysis during activation or electrolysis.
[43]
Specifically, when the electrode for electrolysis is activated or electrolyzed, the particles containing the ruthenium element in the catalyst layer become metallic elements without changing their structure or partially hydrated and are reduced to active species. In addition, the particles containing the element cerium in the catalyst layer have a needle-like structure and act as a protective material to prevent the physical drop-off of the particles containing the element ruthenium in the catalyst layer. It is possible to prevent the loss of ruthenium element. The cerium oxide includes all kinds of oxide forms in which cerium element and oxygen atom are combined, and in particular, may be an oxide of (II), (III) or (IV).
[44]
[45]
A molar ratio between the ruthenium element and the cerium element included in the coating layer may be 100:5 to 100:30, preferably 100:10 to 100:20. When the molar ratio of the ruthenium element and the cerium element included in the coating layer is within the above-mentioned range, the balance between the durability of the electrode for electrolysis and the electrical conductivity may be excellent.
[46]
[47]
In the electrode for electrolysis of the present invention, the coating layer may further include platinum oxide. The platinum element provided by the platinum oxide may act as an active material like elemental ruthenium, and when platinum oxide and ruthenium oxide are included in the coating layer together, it can exhibit superior effects in terms of durability and overvoltage of the electrode. The platinum oxide includes all kinds of oxides in which a platinum element and an oxygen atom are combined, and in particular, may be a dioxide or a tetraoxide.
[48]
[49]
The molar ratio between the ruthenium element and the platinum element included in the coating layer may be 100:2 to 100:20, preferably 100:5 to 100:15. When the molar ratio of the ruthenium element and the platinum element included in the coating layer is within the above range, it is preferable in terms of durability and overvoltage improvement, and when the platinum element is included less than this, durability and overvoltage may deteriorate, and more In this case, it is not advantageous from an economic point of view.
[50]
[51]
Manufacturing method of electrode for electrolysis
[52]
The present invention relates to the steps of applying a coating composition on at least one surface of a metal substrate having a mesh structure having a mesh size of 45 to 60 mesh, and an individual wire thickness of 100 to 160 μm in the mesh structure, and a metal substrate to which the coating composition is applied. It comprises the steps of coating by drying and heat treatment, wherein the coating composition provides a method for producing an electrode for electrolysis comprising a ruthenium precursor and an amine-based additive in a molar ratio of 100:5 to 100:20.
[53]
[54]
In the method of manufacturing an electrode for electrolysis of the present invention, the metal substrate may be the same as the metal substrate of the electrode for electrolysis described above.
[55]
[56]
In the method of manufacturing an electrode for electrolysis of the present invention, the coating composition may include a ruthenium precursor and an amine-based additive. The ruthenium precursor is oxidized and converted into an oxide in a heat treatment step after coating.
[57]
The ruthenium precursor may be used without particular limitation as long as it is a compound capable of forming ruthenium oxide, for example, may be a hydrate, hydroxide, halide or oxide of ruthenium, specifically ruthenium hexafluoride (RuF 6 ), ruthenium ( III) chloride (RuCl 3 ), ruthenium (III) chloride hydrate (RuCl 3 ·xH 2 O), ruthenium (III) bromide (RuBr 3 ), ruthenium (III) bromide hydrate (RuBr 3 ·xH 2 O), ruthenium eye Odide (RuI 3 ) and may be at least one selected from the group consisting of ruthenium acetate salt. When using the ruthenium precursors listed above, the formation of ruthenium oxide may be easy.
[58]
[59]
In the method of manufacturing an electrode for electrolysis of the present invention, the coating composition may further include an amine-based additive for imparting strong adhesion between the coating layer and the metal substrate. In particular, the amine-based additive improves the bonding force between the ruthenium elements included in the coating layer, and adjusts the oxidation state of the particles containing the ruthenium element, so that the electrode can be manufactured in a form more suitable for reaction.
[60]
[61]
The amine-based additive used in the present invention is particularly suitable for use in forming a coating layer because of its high solubility in water while having an amine group. Amine-based additives that can be used in the present invention include melamine, ammonia, urea, 1-propylamine, 1-butylamine, 1-pentylamine, 1-heptylamine, 1-octylamine, 1-nonylamine, 1-dode and silamine, and at least one selected from the group consisting of these may be used.
[62]
In the electrode for electrolysis of the present invention, the ruthenium element and the amine-based additive of the coating layer may be included in a molar ratio of 100:20 to 100:40, preferably 100:25 to 100:35. When the amount of the amine-based additive is less than this, the effect of improving the bonding strength by the additive is insignificant, and when the amount of the amine-based additive is included in more than this amount, precipitates are likely to occur in the coating solution, thereby reducing the uniformity of the coating and may interfere with the function of ruthenium oxide.
[63]
[64]
The coating composition may further include a cerium precursor for forming cerium oxide in the coating layer. The cerium precursor may be used without particular limitation as long as it is a compound capable of forming cerium oxide, for example, may be a hydrate, hydroxide, halide or oxide of cerium element, specifically cerium (III) nitrate hexahydrate (Ce (NO 3 ) 3 .6H 2 O), cerium(IV) sulfate tetrahydrate (Ce(SO 4 ) 2 .4H 2 O) and cerium(III) chloride heptahydrate (CeCl 3 .7H 2 O) It may be one or more selected cerium precursors. When using the cerium precursors listed above, the formation of cerium oxide can be facilitated.
[65]
[66]
The coating composition may further include a platinum precursor for forming a platinum oxide in the coating layer. The platinum precursor may be used without particular limitation as long as it is a compound capable of forming platinum oxide, for example, chloroplatinic acid hexahydrate (H 2 PtCl 6 .6H 2 O), diamine dinitro platinum (Pt(NH 3 ) 2 ( consisting of NO) 2 ) and platinum(IV) chloride (PtCl 4 ), platinum(II) chloride (PtCl 2 ), potassium tetrachloroplatinate (K 2 PtCl 4 ), potassium hexachloroplatinate (K 2 PtCl 6 ) One or more platinum precursors selected from the group may be used. When using the platinum precursors listed above, the formation of platinum oxide can be facilitated.
[67]
[68]
In the method of manufacturing an electrode for electrolysis of the present invention, an alcohol-based solvent may be used as a solvent for the coating composition. When an alcohol-based solvent is used, it is easy to dissolve the components described above, and it is possible to maintain the bonding strength of each component even at a stage in which the coating layer is formed after application of the coating composition. Preferably, at least one of isopropyl alcohol and butoxyethanol may be used as the solvent, and more preferably a mixture of isopropyl alcohol and butoxyethanol may be used. When isoprepol alcohol and butoxyethanol are mixed and used, a uniform coating can be performed compared to using alone.
[69]
[70]
In the manufacturing method of the present invention, it may include a step of pre-treating the metal substrate before performing the coating step.
[71]
The pretreatment may be to form irregularities on the surface of the metal substrate by chemical etching, blasting, or thermal spraying of the metal substrate.
[72]
The pretreatment may be performed by sandblasting the surface of the metal substrate to form fine irregularities, and treating with salt or acid. For example, the surface of the metal substrate may be sandblasted with alumina to form irregularities, immersed in an aqueous sulfuric acid solution, washed, and dried to pre-treat to form detailed irregularities on the surface of the metal substrate.
[73]
[74]
The application is not particularly limited as long as the catalyst composition can be evenly applied on the metal substrate and may be performed by a method known in the art.
[75]
The application may be performed by any one method selected from the group consisting of doctor blade, die casting, comma coating, screen printing, spray spraying, electrospinning, roll coating, and brushing.
[76]
[77]
The drying may be performed at 50° C. to 300° C. for 5 minutes to 60 minutes, and is preferably performed at 50° C. to 200° C. for 5 minutes to 20 minutes.
[78]
When the above conditions are satisfied, the solvent can be sufficiently removed and energy consumption can be minimized.
[79]
[80]
The heat treatment may be performed at 400° C. to 600° C. for 1 hour or less, and is preferably performed at 450° C. to 550° C. for 5 minutes to 30 minutes.
[81]
When the above-described conditions are satisfied, impurities in the catalyst layer may be easily removed and the strength of the metal substrate may not be affected.
[82]
[83]
Meanwhile, the coating may be performed by sequentially repeating application, drying, and heat treatment so that 10 g or more of ruthenium oxide per unit area (m 2 ) of the metal substrate becomes. That is, in the manufacturing method according to another embodiment of the present invention, after coating, drying and heat treatment of the catalyst composition on at least one surface of the metal substrate, and then re-coating, drying and Coating with heat treatment may be repeatedly performed.
[84]
[85]
Hereinafter, examples and experimental examples will be described in more detail to describe the present invention in detail, but the present invention is not limited by these examples and experimental examples. Embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art.
[86]
[87]
material
[88]
In this embodiment, the ruthenium precursor is ruthenium (III) chloride hydrate (RuCl 3 ·nH 2 O), the platinum precursor is platinum (IV) chloride, and the cerium precursor is cerium (III) nitrate hexahydrate (Ce(NO 3 ) 3 6H 2 O) was used. In addition, urea was used as an amine-based additive, and a mixture of 2.375 ml of isopropyl alcohol and 2.375 ml of 2-butoxyethanol was used as a solvent for the coating composition.
[89]
[90]
Preparation of coating composition
[91]
In the mixed solvent of the above materials, 2.41 mmol of ruthenium (III) chloride hydrate, 0.842 mmol of cerium (III) nitrate hexahydrate (Ce(NO 3 ) 3 .6H 2 O) and 0.1928 mmol of platinum (IV) chloride were added 1 After sufficient dissolution for a period of time, 0.045 g of urea was added and mixed to prepare a coating composition.
[92]
[93]
Pretreatment of metal substrates
[94]
Before forming the coating layer on the metal substrate, after sandblasting the surface of the substrate to be used in each Example and Comparative Example with aluminum oxide (White alumina, F120) at 0.4 MPa, 5M H 2 SO heated to 80 ° C. 4 It was placed in an aqueous solution, treated for 3 minutes, and washed with distilled water to complete the pretreatment.
[95]
[96]
Example 1
[97]
After pretreatment of a nickel mesh (99% or more purity) having a wire thickness of 120 μm and a mesh size of 60 mesh through the pretreatment method described above, the pre-prepared coating composition was coated on the pretreated nickel mesh using a brush. After that, it was dried in a convection drying oven at 180° C. for 10 minutes, and further heat-treated in an electric heating furnace at 500° C. for 10 minutes. After performing these coating, drying and heat treatment processes an additional 9 times, finally heat treatment was performed in an electric heating furnace at 500° C. for 1 hour to prepare an electrode for electrolysis.
[98]
[99]
Example 2
[100]
An electrode for electrolysis was prepared in the same manner as in Example 1, except that a nickel mesh having a wire thickness of 150 μm and a mesh size of 60 mesh (purity of 99% or more) was used.
[101]
[102]
Example 3
[103]
An electrode for electrolysis was prepared in the same manner as in Example 1, except that a nickel mesh having a wire thickness of 150 μm and a mesh size of 50 mesh (purity of 99% or more) was used.
[104]
[105]
Comparative Example 1
[106]
An electrode for electrolysis was prepared in the same manner as in Example 1, except that a nickel mesh having a wire thickness of 150 μm and a mesh size of 40 mesh (purity of 99% or more) was used.
[107]
[108]
Comparative Example 2
[109]
An electrode for electrolysis was prepared in the same manner as in Example 1, except that a nickel mesh having a wire thickness of 150 μm and a mesh size of 30 mesh (purity of 99% or more) was used.
[110]
[111]
Comparative Example 3
[112]
An electrode for electrolysis was prepared in the same manner as in Example 1, except that a nickel mesh having a wire thickness of 150 μm and a mesh size of 80 mesh (purity of 99% or more) was used.
[113]
[114]
Comparative Example 4
[115]
An electrode for electrolysis was prepared in the same manner as in Example 1, except that a nickel mesh having a wire thickness of 180 μm and a mesh size of 60 mesh (purity of 99% or more) was used.
[116]
[117]
Comparative Example 5
[118]
An electrode for electrolysis was prepared in the same manner as in Example 1, except that a nickel mesh having a wire thickness of less than 80 μm and a mesh size of 60 mesh (purity of 99% or more) was used.
[119]
[120]
Comparative Example 6
[121]
An electrode for electrolysis was prepared in the same manner as in Example 1, except that the platinum precursor and urea were excluded from the coating composition.
[122]
[123]
The metal substrate structure of the electrodes prepared in Examples and Comparative Examples and the ruthenium and nitrogen contents in the catalyst layer were confirmed by EDX analysis and summarized in Table 1 below. As equipment used for EDX analysis, a Bruker D4 Endeavor was used.
[124]
[125]
[Table 1]
Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6
Mesh size
(unit: mesh) 60 60 50 40 30 80 60 60 60
Wire thickness
(μm) 120 150 150 150 150 150 180 >80 120
Ru (mol%) in electrode 18 14 15 17 26 23 16 23 26
N (mol%) in electrode 9 7 7 7 9 9 7 10 4
N/Ru x 100 (mol%) 50 50 46 41 35 39 44 43 15
[126]
[127]
Comparative Examples 1-3 are for a case outside the mesh size range of the present invention, Comparative Examples 4-5 are for a case outside the individual wire thickness of the present invention, and Comparative Example 6 is a case of some of the coating layer components of the present invention This is for the case where is not included. In the case of Examples, the coating was performed smoothly, so that the nitrogen-to-ruthenium ratio was higher than that of Comparative Examples, and in particular, in Comparative Example 6 in which urea was not included in the coating composition, the nitrogen content was significantly lower than in other Examples and Comparative Examples. indicated.
[128]
[129]
Experimental Example 1. Confirmation of the performance of the prepared electrode for electrolysis
[130]
In order to confirm the performance of the electrodes prepared in Examples and Comparative Examples, a performance test in brine electrolysis (Chlor-Alkali Electrolysis) was performed. As the performance test equipment, lab-scale zero-gap single-cell test equipment was used, and the cell size was 50 x 50 mm and Aciplex F6808 membrane was used. The prepared electrode for electrolysis was used as the negative electrode, and a commercial AKC electrode was used as the positive electrode (anode). Test conditions were a current density of 6.2 kA/m 2 , a sodium chloride solution of 305 g/L concentration of the anolyte, 30.6% NaOH aqueous solution of the catholyte, and a reaction temperature of 90° C., and the voltage under the test conditions was measured. The measured voltage values ​​are shown in Table 2 below.
[131]
[132]
[Table 2]
division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6
Voltage (at 6.2 kA/m 2 , in V) 3.129 3.087 3.093 3.133 3.151 3.240 3.096 3.220 3.156
[133]
[134]
From the above results, it was confirmed that in Comparative Examples 1 to 3, in which the mesh size was outside the range of the present invention, the electrode performance was inferior to that of the embodiment of the present invention. In addition, it was confirmed that Comparative Example 6, which does not contain nitrogen among the coating layer components of the present invention, also had inferior electrode performance compared to the Example of the present invention. Furthermore, in the case of Comparative Example 5 using a mesh structure having a wire thickness thinner than the range of the present invention, it was also confirmed that the electrode performance compared to the Example was inferior. On the other hand, in the case of Comparative Example 4 having a thicker wire than the Example, the electrode performance was similar to that of the Example of the present invention.
[135]
[136]
Experimental Example 2. Confirmation of loss of coating layer before and after acceleration test
[137]
The presence or absence of loss of the coating layer was checked before and after the accelerated test of the electrodes prepared in Examples and Comparative Examples. The accelerated test was performed using the prepared electrode as a half cell, and after electrolytic reaction for 1 hour at a constant current density (60 kA/m 2 ) through galvanometry, the metal content of the coating layer before and after acceleration was measured through an XRF analysis device. Confirmed. A 32% sodium hydroxide aqueous solution was used as the electrolyte solution, a Pt wire was used as a counter electrode, and a Hg/HgO electrode was used as a reference electrode. The composition ratios of ruthenium, cerium and platinum components of the coating layer before and after the accelerated test are shown in Table 3 below.
[138]
[139]
[Table 3]
before accelerated test after acceleration test Ru change
(%)
Ru Ce Pt Ru Ce Pt
Example 1 5.27 3.89 2.56 5.14 3.65 1.99 97.5
Example 2 5.57 4.41 2.87 5.39 3.83 2.37 96.8
Example 3 5.33 4.20 2.62 5.27 3.91 2.27 98,8
Comparative Example 1 4.94 5.05 2.63 5.01 4.22 2.32 101.4
Comparative Example 2 4.89 4.59 2.77 5.09 3.38 2.40 104.1
Comparative Example 3 5.41 4.09 2.83 5.72 3.40 2.97 105.7
Comparative Example 4 5.06 4.71 2.73 4.26 3.84 2.34 75.9
Comparative Example 5 4.79 4.42 2.51 4.70 3.78 2.42 98.1
Comparative Example 6 5.10 4.56 - 5.02 4.12 - 98.4
[140]
[141]
From the above results, it was found that, while almost no coating layer peeling occurred in the example of the present invention, about 25% of the ruthenium peeling occurred in Comparative Example 4, which exhibited an overvoltage similar to that of the present invention. Such drop-off of the coating layer is a factor that prevents the electrolysis reaction from proceeding uniformly. On the other hand, it was confirmed that the amount of change in Ru in Comparative Examples 1 to 3 was 100% or more due to a measurement error.
Claims
[Claim 1]
metal base layer; and a coating layer comprising ruthenium oxide and nitrogen, wherein the metal base layer has a mesh structure having a mesh size of 45 to 60 mesh, and an individual wire thickness of the mesh structure is 100 to 160 μm, and nitrogen in the coating layer The content is 30 to 70 mol% of the ruthenium oxide electrode for electrolysis.
[Claim 2]
The electrode for electrolysis according to claim 1, wherein the mesh size of the metal base layer is 50 to 60 mesh.
[Claim 3]
The electrode for electrolysis according to claim 1, wherein the thickness of each wire of the mesh structure is 120 to 150 μm.
[Claim 4]
The electrode for electrolysis according to claim 1, wherein the coating layer further comprises cerium oxide.
[Claim 5]
The electrode for electrolysis according to claim 4, wherein a molar ratio between elemental ruthenium and elemental cerium in the coating layer is 100:5 to 100:30.
[Claim 6]
The electrode for electrolysis according to claim 1, wherein the coating layer further comprises platinum oxide.
[Claim 7]
The electrode for electrolysis according to claim 6, wherein the molar ratio between the ruthenium element and the platinum element in the coating layer is 100:2 to 100:20.
[Claim 8]
applying a coating composition on at least one side of a metal substrate having a mesh structure having a mesh size of 45 to 60 mesh, and an individual wire thickness of 100 to 160 μm in the mesh structure; and drying and heat treating the metal substrate to which the coating composition is applied, and coating the coating composition, wherein the coating composition contains a ruthenium precursor and an amine-based additive in a molar ratio of 100:20 to 100:40. manufacturing method.
[Claim 9]
The method of claim 8, wherein the amine-based additive is melamine, ammonia, urea, 1-propylamine, 1-butylamine, 1-pentylamine, 1-heptylamine, 1-octylamine, 1-nonylamine and 1-dode A method for producing an electrode for electrolysis of at least one selected from the group consisting of silamine.
[Claim 10]
The method of claim 8, wherein the coating composition further comprises a cerium precursor and a platinum precursor.