Recovery method of catalyst for hydrogen production by electrolysis of water and equipment for hydrogen production by electrolysis of water

Abstract

The invention belongs to the technical field of catalyst recovery, and provides a recovery method of a catalyst for hydrogen production by water electrolysis of a proton exchange membrane and equipment for hydrogen production by water electrolysis, and the recovery method comprises the following steps: selecting an anode target organic solution and a cathode target organic solution, the method comprises the following steps: respectively placing used membrane electrodes for producing hydrogen by electrolyzing water in an anode target organic solution and a cathode target organic solution for pretreatment operation so as to respectively dissolve a binder between an anode catalyst layer of the membrane electrode and a proton exchange membrane and a binder between a cathode catalyst layer of the membrane electrode and the proton exchange membrane; and respectively carrying out mechanical separation operation and drying operation on the anode catalyst layer and the cathode catalyst layer on the surface of the pretreated membrane electrode to obtain an anode catalyst and a cathode catalyst. According to the technical scheme, the anode catalyst and the cathode catalyst for hydrogen production through water electrolysis are recycled respectively, and the problems that in catalyst recycling, recycling energy consumption is high, the process is complex, cost is high, and pollution is serious are solved.

Description

Technical Field

[0001] The present application belongs to the technical field of catalyst recovery, and relates to a method for recovering a catalyst for producing hydrogen by electrolysis of water and a device for producing hydrogen by electrolysis of water. Background Art

[0002] PEM (Proton Exchange Membrane) water electrolysis refers to a method of producing hydrogen by electrolyzing water through a proton exchange membrane. In the process of PEM water electrolysis, water molecules first undergo an oxidation reaction on the anode side of the PEM electrolyzer, and after losing electrons, they generate oxygen and protons (hydrogen ions, H+). The protons are then conducted to the cathode side through the proton exchange membrane (PEM). On the cathode side, the protons undergo a reduction reaction after gaining electrons to generate hydrogen.

[0003] In the process of PEM water electrolysis, platinum group metals are often used as catalysts for electrode reactions. Platinum group metal resources are precious, and after hydrogen production is completed, the catalyst needs to be recovered from the proton exchange membrane for reuse. In the prior art, the process of hydrometallurgy or pyrometallurgy will produce toxic wastewater or hydrogen fluoride gas, so there is a pollution problem. In addition, in the prior art, the catalysts of the cathode and anode are mixed together during the recovery process, and further separation and cleaning are required later, which increases the cost and hinders large-scale and industrial applications. Summary of the invention

[0004] The present application aims to provide a method for recovering a catalyst for hydrogen production by electrolysis of water and a device for hydrogen production by electrolysis of water, so as to solve the problems of high energy consumption, complex process, high cost and serious pollution in the recovery of catalyst for hydrogen production by electrolysis of water.

[0005] The embodiment of the present application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a method for recovering a catalyst for producing hydrogen by electrolysis of water, comprising:

[0007] S11, selecting an anode target organic solution and a cathode target organic solution, placing a used membrane electrode for hydrogen production by water electrolysis in the anode target organic solution and the cathode target organic solution for pretreatment operations, respectively, to dissolve a binder between the anode catalyst layer of the membrane electrode and the proton exchange membrane, and a binder between the cathode catalyst layer of the membrane electrode and the proton exchange membrane;

[0008] S12, performing mechanical separation operation and drying operation on the anode catalyst layer and the cathode catalyst layer on the surface of the membrane electrode after the pretreatment operation, respectively, to obtain the anode catalyst and the cathode catalyst.

[0009] Optionally, selecting an anode target organic solution and a cathode target organic solution comprises:

[0010] respectively preparing the anode target organic solution and the cathode target organic solution;

[0011] Wherein, the anode target organic solution and the cathode target organic solution are prepared according to one or more formula solvents; the formula solvent includes at least one of ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and water.

[0012] Optionally, configuring the anode target organic solution and the cathode target organic solution includes:

[0013] The formula solvent is configured based on a preset formula to obtain a plurality of configured organic solvents;

[0014] Placing a plurality of first membrane electrodes respectively in each of the configured organic solvents for pretreatment operation;

[0015] The anode catalyst layer and the cathode catalyst layer on the surface of the first membrane electrode after pretreatment are respectively subjected to mechanical separation and drying operations to obtain the anode catalyst and the cathode catalyst;

[0016] Obtaining the recovery rate of the catalyst in the currently configured organic solvent according to the mass of the catalyst corresponding to each configured organic solvent;

[0017] Determining the anode target organic solution and the cathode target organic solution from a plurality of the configured organic solvents according to the recovery rate of the catalyst and the membrane swelling phenomenon of the first membrane electrode when placed in the configured organic solvent;

[0018] The anode target organic solution and the cathode target organic solution are configured according to the preset formula corresponding to the anode target organic solution and the cathode target organic solution.

[0019] Optionally, when the formulation solvent includes ethanol, the volume ratio of the ethanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or

[0020] In the case where the formulation solvent includes n-propanol, the volume ratio of the n-propanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or

[0021] In the case where the formulation solvent includes isopropanol, the volume ratio of the isopropanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or

[0022] In the case where the formulation solvent includes n-butanol, the volume ratio of the n-butanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or

[0023] In the case where the formulation solvent includes isobutanol, the volume ratio of the isobutanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or

[0024] In the case where the formulation solvent includes n-pentanol, the volume ratio of the n-pentanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or

[0025] In the case where the formulation solvent includes water, the volume ratio of the water to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.5.

[0026] Optionally, when the formula solvent includes n-propanol and water, the volume ratio of the n-propanol to the anode target organic solution or the cathode target organic solution is 0.2, and the volume ratio of the water to the anode target organic solution or the cathode target organic solution is 0.8.

[0027] Optionally, the anode target organic solution includes ethanol, n-propanol, and water, and the volume ratio of ethanol, n-propanol, and water is 1:1:8; the cathode target organic solution includes isopropanol, n-butanol, and water, and the volume ratio of isopropanol, n-butanol, and water is 1:1:8.

[0028] Optionally, the duration of the preprocessing operation is greater than or equal to two hours.

[0029] Optionally, the mechanical separation operation includes:

[0030] The membrane electrode after the pretreatment operation is fixedly placed on a smooth substrate;

[0031] The anode catalyst layer and the cathode catalyst layer of the membrane electrode are peeled off respectively by a separation tool.

[0032] Optionally, the drying operation includes:

[0033] Placing the anode catalyst and cathode catalyst in a vacuum drying oven for vacuum drying;

[0034] Alternatively, the anode catalyst and the cathode catalyst are placed in a low-temperature oven for oven drying respectively.

[0035] In a second aspect, an embodiment of the present application provides a water electrolysis hydrogen production device, which uses a catalyst recovered by the method in the above embodiment to electrolyze water to produce hydrogen.

[0036] In the technical solution of the embodiment of the present application, the membrane electrode for hydrogen production by electrolysis of water is pretreated by a configured organic solution to dissolve the binder between the anode catalyst layer and the proton exchange membrane on the membrane electrode, and the binder between the cathode catalyst layer and the proton exchange membrane, respectively, and then the anode catalyst layer and the cathode catalyst layer are separated from the membrane electrode by physical and mechanical separation. Compared with the catalyst recovery method in the prior art, in the technical solution of the present application, the swelling degree of the membrane is small, and the anode catalyst and the cathode catalyst are recovered separately, and there is no need to further separate the two catalysts later, the processing steps are few, the cost is lower, and the recovery of the catalyst does not produce toxic wastewater or gas, and the catalyst can be recovered efficiently and on a large scale while improving the utilization efficiency of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A schematic diagram of the steps of a method for recovering a catalyst for producing hydrogen by electrolysis of water provided in an embodiment of the present application;

[0039] Figure 2 A schematic diagram of the steps for configuring a target organic solution provided in an embodiment of the present application;

[0040] Figure 3 A schematic diagram of the process for recovering the catalyst provided in the embodiments of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0043] In this application, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. In addition, in the description of this application, the term "including" means "including but not limited to". The terms first, second, third, etc. are used only as labels and do not impose numerical requirements or establish an order.

[0044] In this application, "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0045] In the present application, "at least one" means one or more, and "plurality" means two or more. "One or more", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0046] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0047] During the research, the applicant found that platinum group metals (PGMs) are usually used as catalysts for electrode reactions because of their excellent catalytic activity and chemical stability under harsh acidic and oxidizing conditions. Among them, iridium (Ir) can be used as a catalyst for the anode oxygen evolution reaction (OER) because of its good activity and stability under acidic conditions. On the cathode side, platinum (Pt) can be used as a catalyst for the hydrogen evolution reaction (HER).

[0048] After the proton exchange membrane (PEM) electrolyzes water, the platinum group metals used as catalysts need to be recovered. Currently, hydrometallurgy or pyrometallurgy is more commonly used for recovery.

[0049] The recovery of platinum metal by hydrometallurgy includes a leaching stage and a separation and purification stage. In the leaching stage, the inorganic acid-oxidant mixture dissolves the platinum into a metal ion complex. After the platinum metal is dissolved, it is separated and purified by ion exchange, chemical precipitation, extraction and other processes. However, since concentrated acid (the solution required to dissolve the metal) is used in the hydrometallurgical process, the process produces toxic wastewater.

[0050] Taking the metal enrichment method as an example, the pretreated waste catalyst is mixed with a metal collector such as copper, nickel, iron, matte or its corresponding oxide / reducing agent, and a suitable flux, and then melted in a high-temperature furnace. The platinum group metals in the waste catalyst are enriched in the metal phase or converted into other easy-to-handle compounds, which are separated from the slag phase containing the carrier material and the added flux. Subsequently, the alloy containing the platinum group metals is further refined to produce high-purity platinum group metals. In the PEM electrolysis water, the catalyst contains ionomers, so hydrogen fluoride (HF) gas is easily generated during the combustion process of pyrometallurgy, which is easy to cause pollution. In addition, in the related art, the anode catalyst and the cathode catalyst are mixed together during the recovery process, and further separation and cleaning are required later, which increases the cost and hinders large-scale and industrial applications.

[0051] Therefore, an embodiment of the present application proposes a method for recovering a catalyst for hydrogen production by electrolysis of water, by respectively dissolving the binder between the anode catalyst layer and the proton exchange membrane, and the binder between the cathode catalyst layer and the proton exchange membrane on the membrane electrode, and then recovering the anode catalyst and the cathode catalyst respectively by mechanical separation. This can reduce subsequent process steps, reduce recycling costs, and reduce toxic wastewater or waste gas generated during the catalyst recovery process, thereby efficiently and large-scale recovering the catalyst.

[0052] Please see Figure 1 , Figure 1 A schematic diagram of the steps of a method for recovering a catalyst for producing hydrogen by electrolysis of water provided in an embodiment of the present application. The method for recovering a catalyst for producing hydrogen by electrolysis of water may include:

[0053] Step S11, select an anode target organic solution and a cathode target organic solution, and place the used membrane electrode for hydrogen production by water electrolysis in the anode target organic solution and the cathode target organic solution for pretreatment operations, respectively, to dissolve the binder between the anode catalyst layer of the membrane electrode and the proton exchange membrane, and the binder between the cathode catalyst layer of the membrane electrode and the proton exchange membrane.

[0054] The membrane electrode for hydrogen production by electrolysis of water is a component in the technology of hydrogen production by electrolysis of water. The membrane electrode is composed of a proton exchange membrane, an anode and a cathode. Among them, the proton exchange membrane is located in the center, which plays the role of conducting protons and isolating electrons and gases. The anode catalyst layer and the cathode catalyst layer are respectively located on both sides of the proton exchange membrane, and the membrane electrode is composed of an anode catalyst layer, a cathode catalyst layer and a proton exchange membrane. The anode catalyst layer on the surface of the membrane electrode contains an anode catalyst, and the cathode catalyst layer contains a cathode catalyst, which is the part that needs to be recovered in the embodiment of the present application.

[0055] The pretreatment operation may be immersion dissolution, or heating-assisted dissolution or ultrasonic-assisted dissolution. The binder in the catalyst on the membrane electrode includes a perfluorosulfonic acid polymer. The binder mainly serves to tightly bond the catalyst layer to the proton exchange membrane, thereby maintaining a low contact resistance. When recovering the catalyst, since the catalyst particles need to be separated from the membrane electrode for subsequent purification and reuse, it is necessary to dissolve the binder between the catalyst layer and the proton exchange membrane, destroy the connection between the binder and the proton exchange membrane, and make the catalyst layer easier to peel off from the proton exchange membrane. In this application, the difference between the anode and the cathode after use is used to select the anode target organic solution and the cathode target organic solution to respectively increase the solubility of the binder in the anode catalyst and the solubility of the binder in the cathode catalyst, thereby facilitating the recovery of the anode catalyst and the cathode catalyst, respectively, and improving the recovery rate of the anode catalyst and the cathode catalyst, respectively.

[0056] In the embodiments of the present application, the catalyst for producing hydrogen by electrolysis of water is a platinum group metal (PGMs), such as iridium, platinum, and the like.

[0057] In some optional embodiments, step S11 may include respectively preparing an anode target organic solution and a cathode target organic solution, wherein the anode target organic solution and the cathode target organic solution are prepared according to one or more formulation solvents; the formulation solvent may include one or more of water, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and n-pentanol.

[0058] In some optional embodiments, the binder can be directly dissolved by the prepared anode target organic solution and cathode target organic solution. The target organic solution can also be prepared according to the catalyst and binder components used in the current membrane electrode before recycling. Figure 2 , Figure 2 A schematic diagram of the steps for configuring a target organic solution provided in an embodiment of the present application. The steps for configuring a target organic solution may include:

[0059] Step S21: configuring the formula solvent based on a preset formula to obtain a plurality of configured organic solvents.

[0060] In some embodiments, the formulation solvent may include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and water (Deionized Water, DI), etc., and the target organic solution is obtained by combining two or more formulation solvents.

[0061] In some embodiments, when the formulation solvent includes ethanol, the ratio of ethanol to the target organic solution can be greater than or equal to 0.1; when the formulation solvent includes n-propanol, the ratio of n-propanol to the target organic solution can be greater than or equal to 0.1; when the formulation solvent includes isopropanol, the ratio of isopropanol to the target organic solution can be greater than or equal to 0.1; when the formulation solvent includes n-butanol, the ratio of n-butanol to the target organic solution can be greater than or equal to 0.1; when the formulation solvent includes isobutanol, the ratio of isobutanol to the target organic solution can be greater than or equal to 0.1; when the formulation solvent includes n-pentanol, the ratio of n-pentanol to the target organic solution can be greater than or equal to 0.1; when the formulation solvent includes water, the ratio of water to the target organic solution can be greater than or equal to 0.5.

[0062] It should be noted that the ratios mentioned in this application specification are all volume ratios.

[0063] When preparing the target organic solution in the above implementation process, it is necessary to ensure that each formula solvent occupies a sufficient proportion in the target organic solution, so as to more effectively dissolve the organic components in the binder. Therefore, the ratio of each formula solvent to the target organic solution can be preset to be greater than or equal to 0.1.

[0064] When the target organic solution includes water, water is used as a solvent, and its high proportion of addition will significantly dilute the concentration of the organic solution. This dilution effect may help reduce the physical properties of the solution, such as viscosity and surface tension, thereby improving the fluidity and permeability of the solvent. When dissolving the binder, it can help the solvent to better penetrate into the binder and improve the dissolution efficiency, so the ratio of water to the target organic solution can be preset to be greater than or equal to 0.5.

[0065] As an optional implementation of the above embodiment, the ratio of ethanol to the target organic solution can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8. The ratio of n-propanol to the target organic solution can be 0.1, 0.2, 0.3, 0.4, 0.5. The ratio of isopropanol to the target organic solution can be 0.1, 0.2, 0.3, 0.4, 0.5. The ratio of n-butanol to the target organic solution can be 0.1, 0.2, 0.3, 0.4, 0.5. The ratio of isobutanol to the target organic solution can be 0.1, 0.2, 0.3, 0.4, 0.5. The ratio of n-pentanol to the target organic solution can be 0.1, 0.2, 0.3, 0.4, 0.5. The ratio of water to the target organic solution can be 0.5, 0.6, 0.7, 0.8. It should be noted that the "target organic solution" mentioned here refers to at least one of the anode target organic solution and the cathode target organic solution.

[0066] Exemplarily, in the embodiment of the present application, a plurality of preset formulas are used to configure the formula solvent. For example, the preset formula may include a configuration organic solvent in which the ratio of n-propanol to ethanol is 5:5, a configuration organic solvent in which the ratio of isopropanol to ethanol is 5:5, a configuration organic solvent in which the ratio of n-butanol to ethanol is 5:5, a configuration organic solvent in which the ratio of isobutanol to ethanol is 5:5, a configuration organic solvent in which the ratio of n-pentanol to ethanol is 5:5, a configuration organic solvent in which the ratio of n-propanol to water is 5:5, a configuration organic solvent in which the ratio of isopropanol to water is 5:5, and ethanol. An organic solvent having a ratio of 5:5 to water, an organic solvent having a ratio of 5:5 to n-butanol, an organic solvent having a ratio of 5:5 to water, an organic solvent having a ratio of 5:5 to isobutanol, an organic solvent having a ratio of 5:5 to water, an organic solvent having a ratio of 2:8 to n-propanol, an organic solvent having a ratio of 2:8 to ethanol, an organic solvent having a ratio of 2:8 to isopropanol, an organic solvent having a ratio of 2:8 to ethanol, an organic solvent having a ratio of 2:8 to n-butanol, an organic solvent having a ratio of 2:8 to ethanol, an organic solvent having a ratio of 2:8 to isobutanol, an organic solvent having a ratio of 2:8 to ethanol, an organic solvent having a ratio of 2:8 to n-pentanol, an organic solvent having a ratio of 2:8 to water agent, an organic solvent in which the ratio of isopropanol to water is 2:8, an organic solvent in which the ratio of ethanol to water is 2:8, an organic solvent in which the ratio of n-butanol to water is 2:8, an organic solvent in which the ratio of isobutanol to water is 2:8, an organic solvent in which the ratio of n-pentanol to water is 2:8, an organic solvent in which the ratio of ethanol to n-propanol to pure water is 1:1:8, an organic solvent in which the ratio of ethanol to isopropanol to pure water is 1:1:8, an organic solvent in which the ratio of n-propanol to n-butanol to pure water is 1:1:8, an organic solvent in which the ratio of isopropanol to n-butanol to water is 1: The organic solvent is configured in a ratio of 1:1:8, the organic solvent is configured in a ratio of ethanol to n-butanol to water in a ratio of 1:1:8, the organic solvent is configured in a ratio of n-propanol to isobutanol to water in a ratio of 1:1:8, the organic solvent is configured in a ratio of isopropanol to isobutanol to water in a ratio of 1:1:8, the organic solvent is configured in a ratio of ethanol to isobutanol to water in a ratio of 1:1:8, the organic solvent is configured in a ratio of n-propanol to n-pentanol to water in a ratio of 1:1:8, the organic solvent is configured in a ratio of isopropanol to n-pentanol to water in a ratio of 1:1:8, the organic solvent is configured in a ratio of ethanol to n-pentanol to water in a ratio of 1:1:8, etc.

[0067] Step S22: placing the plurality of first membrane electrodes in each configured organic solvent for pretreatment operation.

[0068] The first membrane electrode can be a plurality of membrane electrodes of the same specification used in hydrogen production equipment. A first membrane electrode is immersed in each configured organic solvent respectively, and the first membrane electrode is taken out after being immersed for the same time.

[0069] In some embodiments, the target organic solution has the ability to dissolve the binder, so in the pretreatment process, in order to allow the target organic solution to penetrate the membrane electrode surface, interact with the binder, and gradually dissolve it, the duration of the pretreatment operation can be set to be greater than or equal to two hours.

[0070] Step S23, performing mechanical separation and drying operations on the anode catalyst layer and the cathode catalyst layer on the surface of the pretreated first membrane electrode respectively to obtain an anode catalyst and a cathode catalyst.

[0071] The mechanical separation operation and drying operation respectively performed on the anode catalyst layer and the cathode catalyst layer on the surface of the first membrane electrode can be referred to the subsequent description content, which will not be elaborated here.

[0072] Step S24, obtaining the recovery rate of the catalyst in the currently configured organic solvent according to the mass of the catalyst corresponding to each configured organic solvent.

[0073] Step S25 , determining the anode target organic solvent and the cathode target organic solvent from a plurality of configured organic solvents according to the recovery rate and the membrane swelling phenomenon when the first membrane electrode is placed in the configured organic solvent.

[0074] For example, please refer to Table 1, which shows the membrane swelling phenomenon of the membrane electrode and the anode catalyst recovery rate and cathode catalyst recovery rate after the membrane electrode is pretreated with various formula solvents and various configured organic solvents used in the above implementation process.

[0075] Table 1

[0076]

[0077]

[0078]

[0079] It should be noted that the above-mentioned Table 1 is only for illustrative purposes, and is for a variety of configured organic solvents configured when iridium and platinum are used as catalysts in an application scenario. In other application scenarios, other configured organic solvents should be configured due to the different binders used in the catalyst. Table 1 is only an example of the organic solvent formula, and does not constitute a limitation on the organic solvent formula and the proportion of the formula solvents therein.

[0080] Step S26, configuring the anode target organic solvent and the cathode target organic solution according to the preset formulas corresponding to the anode target organic solvent and the cathode target organic solvent.

[0081] It can be determined from Table 1 that when using an organic solvent configured with ethanol, n-propanol and pure water in a volume ratio of 1:1:8, the membrane swelling phenomenon is low and the anode catalyst recovery rate is relatively high. Therefore, it is preferred to use an organic solvent configured with ethanol, n-propanol and pure water in a volume ratio of 1:1:8 as the anode target organic solution.

[0082] It can be determined from Table 1 that when using an organic solvent configured with isopropanol, n-butanol, and pure water in a volume ratio of 1:1:8, the membrane swelling phenomenon is low and the cathode catalyst recovery rate is relatively high. Therefore, it is preferred to use an organic solvent configured with isopropanol, n-butanol, and pure water in a volume ratio of 1:1:8 as the cathode target organic solution.

[0083] Step S12, respectively performing mechanical separation operation and drying operation on the anode catalyst layer and the cathode catalyst layer on the surface of the membrane electrode after the pretreatment operation to obtain the anode catalyst and the cathode catalyst.

[0084] Please see Figure 3 , Figure 3 A schematic diagram of the process for recovering the catalyst provided in the embodiments of the present application.

[0085] Combination Figure 3 In some embodiments, the mechanical separation operation may specifically include: fixing the membrane electrode after the pretreatment operation on a smooth substrate; and peeling off the anode catalyst layer and the cathode catalyst layer of the membrane electrode respectively by a separation tool.

[0086] The smooth substrate may be a material or object with a smooth surface without obvious roughness or unevenness, which can provide a uniform and flat support surface to ensure that the membrane electrode can fit tightly and be stably placed. For example, the smooth substrate may be a glass sheet, a metal sheet, a polymer film or a ceramic sheet.

[0087] The separation tool may be a scraper, a blade, tweezers or a similar tool. The separation tool is inserted between the membrane electrode and the catalyst layer to separate the catalyst layer from the substrate, thereby separating the membrane electrode from the catalyst.

[0088] In some embodiments, the drying operation may include:

[0089] The anode catalyst and the cathode catalyst are placed in a vacuum drying oven respectively for vacuum drying; or, the anode catalyst and the cathode catalyst are placed in a low-temperature oven respectively for oven drying.

[0090] Optionally, vacuum drying can reduce the pressure around the target organic solution in a vacuum, thereby reducing the boiling point of the target organic solution and increasing the evaporation rate. In a vacuum environment, water molecules and other volatile organic solvent molecules can evaporate more easily from the catalyst. Therefore, vacuum drying can be used to remove the target organic solution to obtain the catalyst.

[0091] Optionally, the temperature of the low-temperature oven can be set below the boiling point of the target organic solvent, so as to promote the volatilization of the solvent without causing thermal damage to the catalyst. Taking the volatilization of n-propanol as an example, the boiling point of n-propanol is 97.1°C, so the temperature of the low-temperature oven can be set at 60°C to 70°C to observe the volatilization of the solvent. If the volatilization speed is too slow, gradually increase the temperature.

[0092] The present application is described in detail below through specific embodiments. The following embodiments are only partial embodiments of the present application and are not limitations of the present application.

[0093] Example 1

[0094] The target organic solution includes isopropanol and pure water. The ratio of isopropanol to pure water is 2:8. After the used membrane electrode is pre-treated and soaked for 2 hours, mechanically separated by a scraper, and dried, the recovery rate of the cathode catalyst is 94.26%, and the recovery rate of the anode catalyst is 93.88%. No toxic wastewater or polluted gas is generated during the recycling process.

[0095] Example 2

[0096] The target organic solution includes n-propanol and pure water. The ratio of n-propanol to pure water is 2:8. After the used membrane electrode is pre-treated and soaked for 2 hours, mechanically separated by a scraper, and dried, the recovery rate of the cathode catalyst is 96.56%, and the recovery rate of the anode catalyst is 95.87%. No toxic wastewater or polluted gas is generated during the recycling process.

[0097] Example 3

[0098] The target organic solution includes ethanol and pure water. The ratio of ethanol to pure water is 2:8. After the used membrane electrode is pre-treated and soaked for 2 hours, mechanically separated by a scraper, and dried, the recovery rate of the cathode catalyst is 93.85%, and the recovery rate of the anode catalyst is 94.26%. No toxic wastewater or polluted gas is generated during the recycling process.

[0099] Example 4

[0100] The target organic solution includes ethanol, n-propanol and pure water. The ratio of ethanol to n-propanol to pure water is 1:1:8. After the used membrane electrode is pre-treated and soaked for 2 hours, mechanically separated by a scraper and dried, the recovery rate of the cathode catalyst is 97.25%, the recovery rate of the anode catalyst is 98.69%, and the membrane swelling degree is low. No toxic wastewater and polluted gas are generated during the recovery process.

[0101] Example 5

[0102] The target organic solution includes isopropanol, n-butanol and pure water. The ratio of isopropanol to n-butanol to pure water is 1:1:8. After the used membrane electrode is pre-treated and soaked for 2 hours, mechanically separated by a scraper and dried, the recovery rate of the cathode catalyst is 99.25%, the recovery rate of the anode catalyst is 96.29%, and the membrane swelling degree is low. No toxic wastewater and polluted gas are generated during the recovery process.

[0103] It can be seen that the catalyst recovery in this embodiment does not generate toxic wastewater and polluted gas, and the recovery efficiency is at a high level.

[0104] According to some embodiments of the present application, the formula solvent in Example 4 is selected to prepare the anode target organic solution, and the formula solvent in Example 5 is selected to prepare the anode target organic solution; the used membrane electrode is placed in the anode target organic solution for pretreatment and soaking for 2 hours, and the anode catalyst layer is mechanically separated by a scraper to obtain the anode catalyst; the used membrane electrode is placed in the cathode target organic solution for pretreatment and soaking for 2 hours, and the cathode catalyst layer is mechanically separated by a scraper to obtain the cathode catalyst; and then the obtained anode catalyst and cathode catalyst are respectively dried to complete the recovery, wherein the recovery rate of the anode catalyst is 98.69%, and the recovery rate of the cathode catalyst is 99.25%.

[0105] Based on the same application concept, the embodiment of the present application further provides a water electrolysis hydrogen production device. The water electrolysis hydrogen production device uses the catalyst recovered in the above implementation process to electrolyze water to produce hydrogen.

[0106] The above is a detailed introduction to the catalyst recovery method and water electrolysis hydrogen production equipment for electrolysis of water provided in the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application shall be included in the scope of protection of this application.

Claims

1. A method for recovering a catalyst for producing hydrogen by electrolysis of water, characterized in that: include: S11, selecting an anode target organic solution and a cathode target organic solution, placing a used membrane electrode for hydrogen production by water electrolysis in the anode target organic solution and the cathode target organic solution for pretreatment operations, respectively, to dissolve a binder between the anode catalyst layer of the membrane electrode and the proton exchange membrane, and a binder between the cathode catalyst layer of the membrane electrode and the proton exchange membrane; S12, performing mechanical separation operation and drying operation on the anode catalyst layer and the cathode catalyst layer on the surface of the membrane electrode after the pretreatment operation, respectively, to obtain the anode catalyst and the cathode catalyst.

2. The method according to claim 1, characterized in that The selecting of the anode target organic solution and the cathode target organic solution comprises: respectively preparing the anode target organic solution and the cathode target organic solution; The anode target organic solution and the cathode target organic solution are prepared according to one or more formula solvents; the formula solvents include one or more of water, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and n-pentanol.

3. The method according to claim 2, characterized in that The step of separately configuring the anode target organic solution and the cathode target organic solution comprises: The formula solvent is configured based on a preset formula to obtain a plurality of configured organic solvents; Placing a plurality of first membrane electrodes respectively in each of the configured organic solvents for pretreatment operation; Respectively performing mechanical separation operation and drying operation on the anode catalyst layer and the cathode catalyst layer of the first membrane electrode after pretreatment to obtain the anode catalyst and the cathode catalyst; Obtaining the recovery rate of the catalyst in the currently configured organic solvent according to the mass of the catalyst corresponding to each configured organic solvent; Determining the anode target organic solution and the cathode target organic solution from a plurality of the configured organic solvents according to the recovery rate of the catalyst and the membrane swelling phenomenon of the first membrane electrode when placed in the configured organic solvent; The anode target organic solution and the cathode target organic solution are configured according to the preset formula corresponding to the anode target organic solution and the cathode target organic solution.

4. The method according to claim 2, characterized in that: In the case where the formulation solvent includes ethanol, the volume ratio of the ethanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or In the case where the formulation solvent includes n-propanol, the volume ratio of the n-propanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or In the case where the formulation solvent includes isopropanol, the volume ratio of the isopropanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or In the case where the formulation solvent includes n-butanol, the volume ratio of the n-butanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or In the case where the formulation solvent includes isobutanol, the volume ratio of the isobutanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or In the case where the formulation solvent includes n-pentanol, the volume ratio of the n-pentanol to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.1; and / or In the case where the formulation solvent includes water, the volume ratio of the water to the anode target organic solution or the cathode target organic solution is greater than or equal to 0.

5.

5. The method according to claim 4, characterized in that When the formula solvent includes n-propanol and water, the volume ratio of the n-propanol to the anode target organic solution or the cathode target organic solution is 0.2, and the volume ratio of the water to the anode target organic solution or the cathode target organic solution is 0.

8.

6. The method according to claim 1, characterized in that The anode target organic solution includes ethanol, n-propanol, and water, and the volume ratio of ethanol, n-propanol, and water is 1:1:8; the cathode target organic solution includes isopropanol, n-butanol, and water, and the volume ratio of isopropanol, n-butanol, and water is 1:1:

8.

7. The method according to claim 1, characterized in that The duration of the pretreatment operation is greater than or equal to two hours.

8. The method according to claim 1, characterized in that The mechanical separation operation includes: The membrane electrode after the pretreatment operation is fixedly placed on a smooth substrate; The anode catalyst layer and the cathode catalyst layer of the membrane electrode are peeled off respectively by a separation tool.

9. The method according to claim 1, characterized in that: The drying operation comprises: Placing the anode catalyst and the cathode catalyst in a vacuum drying oven for vacuum drying; Alternatively, the anode catalyst and the cathode catalyst are placed in a low-temperature oven for oven drying respectively.

10. A water electrolysis hydrogen production device, characterized in that: The water electrolysis hydrogen production equipment uses the catalyst recovered by the method according to any one of claims 1 to 9 to electrolyze water to produce hydrogen.

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