Catalyst electrode for ammonia water electrolysis and manufacturing method therefor

Abstract

The present invention relates to a catalyst electrode for ammonia water electrolysis and a manufacturing method therefor, the catalyst electrode comprising: a metal foam support; a catalyst layer comprising active metal particles provided on the metal foam support; and a coating layer comprising PTFE on the catalyst layer.

Description

Catalyst electrode for ammonia water electrolysis and method for manufacturing the same

[0001] This specification relates to a catalytic electrode for ammonia water electrolysis and a method for manufacturing the same.

[0002] Ammonia is the nitrogen compound with the lowest oxidation state and can be generated directly in various industrial processes or through the circulation cycle of nitrogen compounds during the treatment of nitrate nitrogen compounds. Ammonia can be treated by degassing, biological decomposition, chlorine decomposition, and electrochemical decomposition. Among these, the electrochemical oxidation treatment method has recently been receiving much attention due to its economic efficiency, rapid and simple operation, and minimal secondary generation.

[0003] Among the previously known technologies related to hydrogen production using ammonia, there are the thermal decomposition of ammonia and the electrolytic decomposition of aqueous ammonia solutions as methods for producing hydrogen using ammonia as a raw material. In the case of the thermal decomposition of ammonia, since nitrogen and hydrogen are generated simultaneously, there is a limitation in that high-purity hydrogen must be separated using an expensive palladium membrane, resulting in low productivity and economic feasibility. Furthermore, regarding the electrolytic decomposition of aqueous ammonia solutions, not much research has been conducted, and Yejin Yang et al. (JOURNAL OF MATERIALS CHEMISTRY A, v.9, no.19, May 2021, pp.11571-11579) disclosed a technology in which platinum was electrodeposited onto carbon paper via a potential cycling method and used as an ammonia oxidation catalyst. However, conventional research has failed to provide solutions for the problems associated with applying electrodeposition catalysts to commercial ammonia water electrolysis facilities, namely the degradation of catalyst electrode activity and durability that occurs when the electrodeposition catalyst is immersed in ammonia water and then exposed to air.

[0004] The present invention relates to a catalytic electrode for ammonia water electrolysis and a method for manufacturing the same. Specifically, the invention aims to provide a catalytic electrode capable of achieving improved stability in an ammonia water electrolysis process.

[0005] However, the technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below.

[0006] One embodiment of the present invention provides a catalyst electrode for ammonia water electrolysis comprising: a metal foam support; a catalyst layer comprising active metal particles provided on the metal foam support; and a coating layer comprising PTFE on the catalyst layer.

[0007] Another embodiment of the present invention provides a method for manufacturing a catalyst electrode for ammonia water electrolysis, comprising: (A) immersing a metal foam support as a working electrode in an electrolyte solution containing a precursor of an active metal; (B) applying a cyclic voltammetry current to form a catalyst layer containing active metal particles on the metal foam support; and (C) forming a coating layer containing PTFE on the catalyst layer.

[0008] The catalytic electrode for ammonia water electrolysis according to the present invention can minimize the degradation of catalytic performance due to the provision of a coating layer. Furthermore, the catalytic electrode for ammonia water electrolysis according to the present invention can minimize the degradation of catalytic activity even in an environment where it is exposed to ammonia water and dried.

[0009] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description below.

[0010] The present invention is susceptible to various modifications and may have various embodiments, and specific embodiments are to be described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. In describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions may obscure the essence of the present invention.

[0011] In this specification, when a part is described as "comprising" a certain component, it means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0012] In this specification, when a member is described as being located "on" another member, this includes not only cases where a member is in contact with another member, but also cases where another member exists between the two members.

[0013] In this specification, the unit "parts by weight" may refer to the ratio of weight between each component.

[0014] Conventional catalysts for ammonia water electrolysis disclose the use of catalysts prepared by electrodeposition at a lab scale. Furthermore, improved catalytic performance can be achieved when an active metal is prepared by electrodeposition on a metal foam support. However, for such catalysts to be applied to large-scale commercial ammonia electrolysis, it is necessary to use them in membrane electrode assemblies or single cells; in this case, however, there is a problem in that the catalyst electrodes are exposed to ammonia water and, during the drying process in air, suffer from significant degradation of activity and durability due to oxidation of the electrodes. Moreover, when electrodeposition catalysts are applied to membrane electrode assemblies, problems may arise in which detached electrodeposited metal particles block the flow paths within the cell. Accordingly, the inventors conducted research to secure improved catalyst stability and physical durability against ammonia water exposure and completed the present invention.

[0015] The present invention will be described in detail below.

[0016] One embodiment of the present invention provides a catalyst electrode for ammonia water electrolysis comprising: a metal foam support; a catalyst layer comprising active metal particles provided on the metal foam support; and a coating layer comprising PTFE (polytetrafluoroethylene) on the catalyst layer.

[0017] According to one embodiment of the present invention, the active metal particles may be electrodeposited metal crystal particles. Specifically, the active metal particles may be electrodeposited metal crystal particles using a potential cycling method. Furthermore, the active metal particles may be crystal particles having a dendritic or flower-like shape. Since the active metal crystal particles have a dendritic or flower-like shape with a very high specific surface area, they have the advantage of achieving a high ammonia decomposition rate during ammonia water electrolysis.

[0018] According to one embodiment of the present invention, the catalyst layer may be composed of the active metal particles. Specifically, the catalyst layer may be formed of active metal crystal particles formed through electrodeposition.

[0019] According to one embodiment of the present invention, the active metal particles may be provided in an amount of 5 mg / cm² or more and 30 mg / cm² or less. Within the content range of the active metal particles, the activity of the catalyst electrode for ammonia water electrolysis can be maximized. Furthermore, if the range is exceeded, the manufacturing cost increases without increasing the catalyst activity, which may result in a problem of reduced economic feasibility.

[0020] According to one embodiment of the present invention, the coating layer may be provided on the catalyst layer, and furthermore, may also be provided on the surface of a metal foam support exposed where the catalyst layer is not formed. According to one embodiment of the present invention, the coating layer prevents etching of the surface of the metal foam support and the surface of the active metal particles due to repeated oxidation-reduction during the ammonia water electrolysis process, and further prevents the detachment of the active metal particles, thereby minimizing the degradation of the catalyst electrode's activity and improving physical stability.

[0021] According to one embodiment of the present invention, the coating layer comprises PTFE (polytetrafluoroethylene). Specifically, the coating layer may be made of PTFE. Unlike other polymer materials, PTFE has the advantage of minimizing the reduction of catalytic activity even when provided on the surface of the active metal particles. Furthermore, as described above, corrosion and / or detachment of the active metal particles during repeated oxidation-reduction in the ammonia water electrolysis process can be effectively prevented, thereby minimizing the performance degradation of the catalytic electrode.

[0022] According to one embodiment of the present invention, the amount of PTFE may be 10 to 50 parts by weight per 100 parts by weight of the active metal particles. Specifically, the amount of PTFE may be 20 to 40 parts by weight, or more than 20 parts by weight and less than 40 parts by weight, per 100 parts by weight of the active metal particles. If the amount of PTFE is less than the above range, it may be difficult to effectively prevent corrosion and / or detachment of the active metal particles. In addition, if the amount of PTFE exceeds the above range, the exposure of the active sites of the catalyst electrode may be restricted due to the formation of an excessively thick coating layer, which may lead to a decrease in catalyst performance.

[0023] The metal foam support above provides a large catalytic active area due to its three-dimensional porous structure and, furthermore, enables smooth mass transfer of liquid and gas during the ammonia water electrolysis reaction, thereby enabling high catalytic activity. Furthermore, the metal foam support above has high electrical conductivity, which enables high electrolysis efficiency to be achieved in the ammonia water electrolysis.

[0024] According to one embodiment of the present invention, the material of the metal foam support may be selected from the group consisting of nickel, iron, and aluminum. Specifically, the material of the metal foam support may be nickel. That is, the metal foam support may be a nickel foam support, in which case more stable support of active metal particles and effective catalytic activity of the active metal particles can be achieved.

[0025] According to one embodiment of the present invention, the active metal may be selected from the group consisting of platinum, iridium, rhodium, palladium, ruthenium, iron, nickel, cobalt, and manganese. The active metal may be one or more metals selected from the group consisting of precious metal catalysts such as platinum, iridium, rhodium, palladium, and ruthenium, and non-precious metal catalysts such as iron, nickel, and cobalt. In terms of promoting the adsorption of ammonia in the ammonia oxidation reaction and significantly improving the electrolysis efficiency of an aqueous ammonia solution, the active metal may be platinum.

[0026] Another embodiment of the present invention provides a method for manufacturing a catalyst electrode for ammonia water electrolysis. Specifically, another embodiment of the present invention provides a method for manufacturing a catalyst electrode for ammonia water electrolysis, comprising: (A) immersing a metal foam support as a working electrode in an electrolyte solution containing a precursor of an active metal; (B) applying a cyclic voltammetry current to form a catalyst layer containing active metal particles on the metal foam support; and (C) forming a coating layer containing PTFE on the catalyst layer.

[0027] Step (A) may be a preparation step for electrodepositing an active metal on the metal foam support using a potential cycling method. Specifically, Step (A) may be a preparation step for a three-electrode system of a reference electrode, a counter electrode, and a working electrode, and the counter electrode and the reference electrode may be further immersed in the electrolyte solution. The counter electrode and reference electrode, etc., not described herein may be appropriately used according to the purpose, in configurations applied to three-electrode systems known in the art. The active metal particles formed using the potential cycling method may be formed in a crystalline form such as a dendritic or flower-like shape, thereby having a very high specific surface area and enabling high catalytic activity.

[0028] According to one embodiment of the present invention, the precursor of the active metal may include at least one of the sulfur oxide, nitrogen oxide, hydroxide, chloride, and acetate of the active metal. For example, when the active metal is platinum, the precursor of the active metal may be chloroplatinic acid (H2PtCl6), platinum chloride (PtCl2, PtCl4), platinum sulfate (Pt(SO4)2), platinum acetate (Pt(C2H3O2)2), or platinum nitrate (Pt(NO3)2). However, it is not limited thereto, and various precursors known for electroplating may be used depending on the desired active metal.

[0029] According to one embodiment of the present invention, the active metal precursor may be included at a concentration of 0.5 to 20 mM, and specifically at a concentration of 1 to 5 mM. If the active metal catalyst precursor is less than the above concentration range, the amount of deposited active metal catalyst is insufficient, and thus the ammonia electrolytic activity may decrease; and if the concentration of the metal catalyst precursor is higher than the above concentration range, the mass activity may decrease due to the excessive formation of aggregated metal particles.

[0030] According to one embodiment of the present invention, the electrolyte solution may further include a supporting electrolyte. The supporting electrolyte may include at least one selected from H2SO4, HNO3, K2SO4, NaCl, HClO4, KOH, NaOH, and HCl. Specifically, the supporting electrolyte may be an acidic supporting electrolyte, and more specifically, may be H2SO4, HNO3, HClO4, or HCl.

[0031] According to one embodiment of the present invention, the supporting electrolyte may be included at a concentration of 0.5 to 5000 mM, specifically at a concentration of 5 to 3000 mM or at a concentration of 100 to 1000 mM. If the electrolyte is less than the above concentration range, the amount of supported metal catalyst may not be sufficient, and if the electrolyte is higher than the above concentration range, agglomeration of the supported active metal may occur, which may reduce the ammonia electrolytic activity.

[0032] According to one embodiment of the present invention, the potential range when the circulating voltage and current are applied may be -0.8 V to 0.8 V, -0.8 V to 0.5 V, or -0.7 V to 0.3 V based on the Ag / AgCl potential. As the absolute value of the negative value increases, the amount of reduction of the active metal increases, and as the absolute value of the positive value increases, the amount of oxidation of the metal foam support may increase.

[0033] According to one embodiment of the present invention, the voltage scan speed when the cyclic voltage current is applied may be 50 mV / s to 500 mV / s. Specifically, the voltage scan speed may be 150 mV / s to 250 mV / s. While a faster voltage scan speed has the advantage of reducing the reaction time, if the above range is exceeded, the reaction proceeds too rapidly compared to the chemical reaction on the surface of the metal foam support, and the active metal may not grow and electrodeposit properly. Furthermore, if the above range is below, the oxidation of the metal foam support in the electrolyte solution proceeds too rapidly, which may significantly lower the mechanical properties of the catalyst electrode.

[0034] According to one embodiment of the present invention, the amount of PTFE may be 10 to 50 parts by weight per 100 parts by weight of the active metal particles. Specifically, the amount of PTFE may be 20 to 40 parts by weight, or more than 20 parts by weight and less than 40 parts by weight, per 100 parts by weight of the active metal particles. As described above, within the content range of PTFE, the coating layer can inhibit corrosion of the active metal particles and / or the metal foam support and improve the stability of the catalyst electrode.

[0035] The above PTFE can be coated on the catalyst layer in various ways. However, to form a more uniform coating layer, the coating layer can be formed using an ultrasonic dispersion coating method.

[0036] According to one embodiment of the present invention, step (C) may involve ultrasonically dispersing coating using a coating dispersion solution in which PTFE is dispersed. Specifically, the ultrasonically dispersing coating may involve injecting the coating dispersion solution onto the surface of the catalyst layer at a rate of 0.1 mL / min to 1 mL / min and performing ultrasonically treatment. When using such ultrasonically dispersing coating, a quantified amount of PTFE can be uniformly provided on the surface of the catalyst layer and the exposed metal foam support.

[0037] According to one embodiment of the present invention, the vibration frequency during the ultrasonic dispersion coating may be 10 to 150 kHz, and the processing time of the ultrasonic dispersion coating may be 1 hour to 3 hours.

[0038] According to one embodiment of the present invention, the ultrasonic dispersion coating may be performed under a temperature range of 50°C to 100°C. Specifically, the ultrasonic dispersion coating may be performed under a temperature range of 70°C to 90°C. More specifically, the temperature may refer to the temperature of a metal foam support on which a catalyst layer is formed. Under the above temperature range, there is an advantage that the PTFE can be more stably provided on the catalyst layer and the exposed surface of the metal foam support.

[0039] Hereinafter, the present invention will be described in detail with reference to examples to specifically explain the invention. However, the embodiments according to the present invention may be modified in various different forms, and the scope of the present invention is not to be interpreted as being limited to the embodiments described below. The embodiments of this specification are provided to more completely explain the present invention to those with average knowledge in the art.

[0040] [Comparative Example 1]

[0041] An electrolyte solution was prepared by dissolving 2 mM H2Cl6Pt·6H2O (Sigma Aldrich) in 200 ml of 0.05 M sulfuric acid (H2SO4, manufacturer: Sigma Aldrich). Then, a porous nickel foam support measuring 2.5 cm x 2.5 cm (nickel main component thickness 1.6 mm, manufacturer: MTI Korea, porosity: ≥ 95%) to be used as the working electrode was washed with acetone, ultrasonically cleaned in approximately 1 M HCl for about 10 minutes, rinsed with water, and dried. A three-electrode cell system was constructed by immersing the nickel foam support as the working electrode, an (Ag / AgCl) electrode as the reference electrode, and a carbon rod as the counter electrode in the electrolyte solution. Furthermore, a cyclic voltammetry current was applied at a voltage scan rate of 200 mV / s under voltage conditions of 0.2 V to -0.4 V (vs. Ag / AgCl) to electrodeposit platinum particles on the nickel foam support, thereby producing a catalyst electrode for ammonia water electrolysis.

[0042] Ammonia oxidation experiments were performed using the ammonia water electrolytic catalyst electrode prepared as described above. Specifically, an Ivium-n-Stat instrument (Ivium Technologies) was used, and measurements were taken in an Ar-purged 1 M KOH electrolyte at room temperature, followed by measurements in Ar-purged 5 M KOH and 2 M NH3 electrolytes. The electrochemical tests were conducted in a three-electrode system using a sealed glass beaker without a membrane (to prevent ammonia evaporation), with an Hg / HgO electrode (1 M KOH) and a Pt mesh used as the reference electrode and counter electrode, respectively. Additionally, the catalyst was subjected to cyclic voltammetry (CV), and the initial catalyst performance was evaluated by applying a voltage within a potential range of -0.2 V to 1.2 V relative to the RHE and measuring the maximum current density when there was no change in the morphology.

[0043] In addition, changes in catalyst performance due to exposure to ammonia water were measured through a wet-dry test. Specifically, the wet-dry test involved immersing the sample in ammonia water and drying the sample at a temperature of approximately 100°C for 1 hour, repeating this process twice, after which the catalyst performance after the wet-dry test was measured through the aforementioned ammonia oxidation experiment.

[0044] [Example 1]

[0045] A catalytic electrode was prepared by electrodepositing platinum particles onto a nickel foam support in the same manner as in Comparative Example 1. At this time, the electrodeposited platinum particles amounted to approximately 0.45 g. Then, a coating dispersion (approx. 9 g) was prepared by dispersing approximately 0.2 parts by weight (approx. 0.09 g) of PTFE relative to the electrodeposited platinum in distilled water at a content of 1 wt%. Subsequently, a catalytic electrode for ammonia water electrolysis was manufactured by forming a coating layer by injecting the prepared coating dispersion onto the surface of the nickel foam support electrodeposited with platinum particles at a rate of approximately 0.6 ml / min and ultrasonically dispersing it at a frequency of approximately 130 kHz. During the formation of the coating layer using ultrasonic dispersion, the nickel foam support electrodeposited with platinum particles was heated to approximately 80 ℃ and ultrasonically treated for approximately 2 hours. Then, the initial catalytic performance and the catalytic performance after a wet-dry test of the manufactured catalytic electrode for ammonia water electrolysis were measured in the same manner as in Comparative Example 1.

[0046] [Comparative Example 2]

[0047] A catalyst electrode for ammonia water electrolysis was prepared in the same manner as in Example 1, except that the coating dispersion in Example 1 was changed to PFSA (perfluorinated sulfonic acid) dispersed in ethanol, and the initial catalyst performance and the catalyst performance after a wet-dry test were measured.

[0048] [Comparative Example 3]

[0049] A catalyst electrode for ammonia water electrolysis was prepared in the same manner as in Example 1, except that the coating dispersion in Example 1 was changed to XA-9 (Sustainion® XA-9 Alkaline Ionomer) dispersed in ethanol, and the initial catalyst performance and catalyst performance after a wet-dry test were measured.

[0050] The initial catalytic performance and catalytic performance after the wet-dry test of the ammonia water electrolysis catalyst electrodes according to Example 1 and Comparative Examples 1 to 3 were as shown in Table 1 below.

[0051] Classification Coating Layer Coating Material / Pt Weight Specific Initial Catalyst Performance (A / cm²) Catalyst Performance After Wet-Dry Test (A / cm²) Catalyst Performance Compared to Initial (%) Comparative Example 1 --1.0 10.6 96 8.3 Example 1 PTFE 0.2 0.9 80.8 48 5.7 Comparative Example 2 PFSA 0.2 0.1 60.1 48 7.5 Comparative Example 3 XA-9 0.2 0.2 10.1 36 1.9

[0052] In the case of Example 1, it was confirmed that the initial catalytic performance was almost the same as that of Comparative Example 1, which did not have a coating layer applied. In contrast, Comparative Examples 2 and 3, which used polymer materials other than PTFE, showed that the catalytic performance decreased to 20% or less due to the presence of the coating layer. Through this, it was found that applying any polymer material as a coating layer can have a very negative effect on catalytic performance, and that, exceptionally, applying PTFE as a coating layer as in the present invention can prevent the degradation of catalytic performance caused by the coating layer.

[0053] In addition, in the case of Comparative Example 1, which did not have a coating layer applied, it was confirmed that the degradation of catalyst performance after the wet-dry test exceeded approximately 30%. In contrast, in the case of Example 1, which had a PTFE coating layer applied, it was confirmed that the degradation of catalyst performance was limited to less than 15% even after the wet-dry test. This suggests that the PTFE coating layer prevented the oxidation and detachment of platinum particles acting as catalytic active sites, and further prevented the corrosion of the nickel foam support.

[0054] [Example 2]

[0055] A catalyst electrode for ammonia water electrolysis was prepared in the same manner as in Example 1, except that a coating dispersion was prepared by dispersing 0.1 parts by weight of PTFE in distilled water at a content of 1 wt% relative to the electrodeposited platinum.

[0056] [Example 3]

[0057] A catalyst electrode for ammonia water electrolysis was prepared in the same manner as in Example 1, except that a coating dispersion was prepared by dispersing 0.3 parts by weight of PTFE in distilled water at a content of 1 wt% relative to the electrodeposited platinum.

[0058] [Example 4]

[0059] A catalyst electrode for ammonia water electrolysis was prepared in the same manner as in Example 1, except that a coating dispersion was prepared by dispersing 0.4 parts by weight of PTFE in distilled water at a content of 1 wt% relative to the electrodeposited platinum.

[0060] The initial catalytic performance of the ammonia water electrolysis catalytic electrodes according to Comparative Example 1 and Examples 1 to 4 was measured as described above, and furthermore, after drying in air at about 60°C for about one day, the catalytic performance after the overnight test was measured through the ammonia oxidation experiment described above.

[0061] The initial catalytic performance and catalytic performance after an overnight test of the ammonia water electrolysis catalyst electrodes according to Comparative Example 1 and Examples 1 to 4 were as shown in Table 2 below.

[0062] Classification Coating Layer Coating Material / Pt Weight Specific Initial Catalyst Performance (A / cm²) Catalyst Performance After Overnight Test (A / cm²) Catalyst Performance Compared to Initial (%) Comparison Example 1 --1.0 10.9 29 1.1 Example 1 PTFE 0.2 0.9 8 0.9 39 4.9 Example 2 PTFE 0.1 0.9 9 0.6 8 6 8.7 Example 3 PTFE 0.3 0.6 1.1 8 19 6.7 Example 4 PTFE 0.4 0.6 4 0.8 3 12 9.7

[0063] Referring to Table 2, even when performing an overnight test under milder conditions than the wet-dry test in Table 1, Comparative Example 1, which did not have a coating layer applied, showed a decrease in catalyst performance of approximately 10%. In contrast, in the case of Example 1, which had a coating layer with a PTFE / Pt weight ratio of 0.2, it was confirmed that only a decrease in catalyst performance of approximately 5% occurred after the overnight test. In the case of Example 2, which had a coating layer with a PTFE / Pt weight ratio of 0.1, the initial catalyst performance was excellent due to the thin coating layer, but it was found that the decrease in catalyst performance after the overnight test was significant due to the excessively small amount of PTFE. Furthermore, in the case of Examples 3 and 4, which had coating layers with a PTFE / Pt weight ratio of 0.3 to 0.4, it was confirmed that the initial catalyst performance was poor because the exposure of the catalyst active sites was limited due to the excessive amount of PTFE. However, in the case of Examples 3 and 4, it was confirmed that the catalyst performance actually increased significantly after the overnight test. This is presumed to be due to the effect of some coating layers peeling off and platinum particles being exposed during the overnight test, and the effect of hydrophobic PTFE preventing oxidation of platinum particles caused by contact with moisture. Referring to the results of Examples 1 to 3 above, considering the initial catalyst performance and the catalyst performance after the overnight test, it was confirmed that Example 1 or 3 had the optimal coating layer applied.

Claims

1. Metal foam support; A catalyst layer comprising active metal particles provided on the metal foam support; and A coating layer containing PTFE on the catalyst layer; comprising Catalytic electrode for ammonia water electrolysis.

2. In Claim 1, A catalyst electrode for ammonia water electrolysis, wherein the above active metal particles are electrodeposited metal crystal particles.

3. In Claim 1, A catalyst electrode for ammonia water electrolysis, wherein the above active metal particles are provided in an amount of 5 mg / cm² or more and 30 mg / cm² or less.

4. In Claim 1, A catalyst electrode for ammonia water electrolysis, wherein the amount of PTFE is 10 to 50 parts by weight per 100 parts by weight of the active metal particles.

5. In Claim 1, A catalyst electrode for ammonia water electrolysis, wherein the material of the metal foam support is selected from the group consisting of nickel, iron, and aluminum.

6. In Claim 1, A catalyst electrode for ammonia water electrolysis, wherein the active metal is selected from the group consisting of platinum, iridium, rhodium, palladium, ruthenium, iron, nickel, cobalt, and manganese.

7. (A) A step of immersing a metal foam support as a working electrode in an electrolyte solution containing a precursor of an active metal; (B) a step of forming a catalyst layer containing active metal particles on the metal foam support by applying cyclic voltammetry; and (C) A step of forming a coating layer containing PTFE on the catalyst layer; comprising, Method for manufacturing a catalyst electrode for ammonia water electrolysis.

8. In Claim 7, (C) A method for manufacturing a catalyst electrode for ammonia water electrolysis, wherein step (C) involves ultrasonically dispersing coating using a coating dispersion solution in which PTFE is dispersed.

9. In Claim 8, A method for manufacturing a catalyst electrode for ammonia water electrolysis, wherein the ultrasonic dispersion coating involves injecting the coating dispersion solution onto the surface of the catalyst layer at a rate of 0.1 mL / min to 1 mL / min and performing ultrasonic treatment.

10. In claim 8, A method for manufacturing a catalyst electrode for ammonia water electrolysis, wherein the amount of PTFE is 10 to 50 parts by weight per 100 parts by weight of the active metal particles.

11. In Claim 8, A method for manufacturing a catalyst electrode for ammonia water electrolysis, wherein the ultrasonic dispersion coating is performed under a temperature range of 50 ℃ to 100 ℃.