Core-shell structured catalytic material, manufacturing method therefor, and use thereof

Abstract

A core-shell structured catalytic material, a manufacturing method therefor, and a use thereof. The core-shell structured catalytic material comprises an anion-modified material serving as a substrate and an anion-conductive material supported on the anion-modified material. An electrode having said core-shell structure is applicable to hydrogen-production operating conditions for water electrolysis containing chloride ions, and efficient hydrogen production processes can be implemented under the operating conditions.

Description

A core-shell structured catalytic material, its manufacturing method and its uses Technical Field

[0001] This invention relates to the field of electrode materials technology. More specifically, this invention relates to a core-shell structured catalytic material, its manufacturing method, and its uses. Background Technology

[0002] Electrolysis of water is an ideal route for producing green hydrogen. However, global freshwater resources are scarce while seawater and industrial saline wastewater are abundant, providing an endless source of raw materials for electrolysis of water to produce hydrogen. However, these low-quality water sources contain a large number of chloride ions, which not only corrode the electrodes but also cause chlorine evolution at the anode, competing with oxygen evolution and affecting the efficiency of the electrolyzer.

[0003] Chinese patent application CN 202211039378.3 provides an electrode for hydrogen production from seawater. The catalyst layer of this application is formed in chloride ions, and a reaction equilibrium is formed with seawater chloride ions. It can exist stably in chloride ions, avoiding the adverse effects of seawater chlorination, and thus has high stability in seawater electrolysis for hydrogen production. Moreover, the electrode can simultaneously catalyze hydrogen production and oxygen production reactions, and has selectivity.

[0004] Chinese patent application CN121023563A discloses a method for preparing a basic cobalt chloride@cobalt-iron spinel composite electrode material and its application. This method employs an alkaline, low-water, high-viscosity alcohol reaction system, utilizing high-temperature conditions to promote the simultaneous deposition of basic cobalt chloride and cobalt-iron spinel materials on a nickel mesh. The prepared basic cobalt chloride@cobalt-iron spinel composite electrode exhibits high catalytic activity and stability, demonstrating excellent electrochemical performance in seawater environments, and can be used as a highly active and stable electrode for seawater electrolysis to produce hydrogen.

[0005] Currently, most existing seawater electrolysis hydrogen production electrodes are mainly modified to repel chloride ions, without considering the issue of reaction selectivity. Summary of the Invention

[0006] The inventors of this invention discovered that constructing an anion-modified catalyst with a carbon core-shell structure can effectively suppress chloride ion adsorption while improving hydroxide ion selectivity. The inner anion-modified catalyst, under the influence of anion groups, effectively suppresses chloride ion adsorption, while the outer carbon layer protects the catalyst's structural stability and improves its electrical conductivity, thereby adsorbing more hydroxide ions and ultimately achieving high hydroxide ion selectivity. This improves the electrolysis efficiency and stability in chloride-containing water electrolysis for hydrogen production. Based on this discovery, this invention completes the preparation of an anion-modified catalyst with a nitrogen-modified carbon core-shell structure and achieves its high catalytic activity and selectivity in alkaline chloride-containing water conditions.

[0007] According to a first aspect of the present invention, there is a core-shell structured catalytic material comprising an anion-modified material as a substrate and an anion-conductive material supported on the anion-modified material.

[0008] According to a second aspect of the present invention, a method for manufacturing a core-shell structured catalytic material is provided, comprising the following steps: providing an anion intercalation material, referred to as a providing step; contacting a carbon precursor and an optional dopant precursor with the anion intercalation material, referred to as a loading step; obtaining a composite precursor; calcining the composite precursor to convert substantially all (e.g., more than 98 wt% of the total amount) of the carbon precursor into elemental carbon, referred to as a calcining step; and obtaining the core-shell structured catalytic material.

[0009] According to a third aspect of the present invention, there is a layered electrode comprising, in sequence, a cathode, an anion exchange membrane, and an anode, wherein an anion-selective blocking material layer is disposed at least at one location: outside the cathode, between the cathode and the anion exchange membrane, and between the anode and the anion exchange membrane, and the anion-selective blocking material is a core-shell structured catalytic material of the present invention or a core-shell structured catalytic material manufactured according to the manufacturing method of the present invention.

[0010] According to a fourth aspect of the invention, there is a method for electrolyzing chloride-containing water (preferably seawater), comprising the step of electrolyzing the chloride-containing water using the layered electrode of the invention.

[0011] According to a fifth aspect of the invention, there is an electrolysis apparatus for chloride-containing water, comprising an electrolysis cell for containing chloride-containing water and the layered electrode of the invention.

[0012] Technical effect

[0013] (1) The anion-modified catalyst with carbon core-shell structure provided by the present invention can effectively inhibit the adsorption of chloride ions and improve the selectivity of hydroxide ions. The inner anion-modified catalyst can effectively inhibit the adsorption of chloride ions under the action of anion groups. The outer carbon layer can protect the structural stability of the catalyst on the one hand, and improve the conductivity of the catalyst on the other hand, thereby adsorbing more hydroxide ions, and finally achieving high-efficiency selection of hydroxide ions, improving its electrolysis efficiency and stability under the condition of chloride ion-containing water electrolysis for hydrogen production.

[0014] (2) The present invention provides a core-shell structure that inhibits the adsorption of chloride ions by repulsion of anionic groups, and maximizes the potential difference between chloride and oxygen evolution reactions by reducing the overpotential of oxygen evolution reaction through optimization of electronic structure, thereby achieving efficient selection of hydroxide ions.

[0015] (3) The core-shell structure electrode provided by the present invention can be applied to the hydrogen production process of water electrolysis containing chloride ions, and can achieve a high-efficiency hydrogen production process under this condition. Attached Figure Description

[0016] Figure 1 is a scanning electron microscope image of the core-shell catalyst prepared in Example 1 of the present invention.

[0017] Figure 2 shows the results of the electrolyte obtained after the electrode reaction in Example 1 of this invention, measured by ultraviolet-visible spectrophotometry. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited to these specific embodiments, but is determined by the claims in the appendix.

[0019] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0020] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0021] In the context of this invention, all numerical values ​​of parameters (e.g., quantity or condition) should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numerical value.

[0022] In the context of this invention, "substantially" means that deviations that are acceptable or reasonable to those skilled in the art are permitted, such as deviations within ±2%, ±1%, ±0.5%, or ±0.1%.

[0023] In the context of this invention, the average lateral and average longitudinal dimensions of the anion intercalation material are measured using a scanning electron microscope. The specific testing steps are as follows: the sample is fixed to a test plate with conductive adhesive, transferred into the test chamber, and subjected to vacuum treatment. After the system conditions are met, the sample morphology is observed. The test scale range is 1-5000 nm. Additionally, the interlayer spacing d(003) is measured as follows: the θ value corresponding to d(00) is obtained from the XRD results of the sample, generally between 5-15°. The obtained θ value is used to calculate the corresponding interlayer spacing d(003) using the Bragg formula 2d(003)sinθ=nλ, where θ is the peak position, n is the diffraction order, and λ is the wavelength of the X-ray.

[0024] In the context of this invention, the anion content in the anion intercalation material can be determined using ion chromatography and organic elemental analysis. Ion chromatography can determine nitrate, chloride, sulfate, and phosphate ions. Specifically, the solid is dissolved in acid to prepare a solution with a concentration of 0-50 ppm, which is then introduced into a chromatographic column for testing. Organic elemental analysis can determine the concentration of carbonate ions. The precursor sample is heated to 900°C in a pure oxygen environment, and the generated gas is separated by a chromatographic column and the carbon content is obtained by passing it through a TCD detector. The carbonate ion content is then deduced from this carbon content.

[0025] In the context of this invention, the method for measuring the metal element content in anion intercalation materials is ICP-MS (inductively coupled plasma atomic emission spectrometry). The sample is digested and prepared into a solution with a concentration range of 0-100 ppm for testing, and then the test results are converted into the actual concentration.

[0026] In the context of this invention, the method for measuring the doping element content and carbon content in anionic conductive materials is to use an organic elemental analysis method. In this method, the precursor sample is burned to 900°C in a pure oxygen environment, and the generated gas is separated by a chromatographic column and then the carbon and nitrogen content is obtained by a TCD detector.

[0027] In the context of this invention, the specific surface area, pore volume, pore size, or average pore size of the core-shell structured catalytic material are measured by nitrogen adsorption / desorption testing, wherein the test medium is nitrogen, the test temperature is -196°C, the specific surface area is calculated by the BET method, and the pore size and pore volume are calculated by the BJH method.

[0028] In the context of this invention, the method for measuring the ionic conductivity of anionic conductive materials is the DC four-probe method.

[0029] In the context of this invention, the SEM measurement method uses a scanning electron microscope SU8020. The specific testing steps are as follows: the sample is fixed on a sample plate, sputtered with gold, and then transferred to the equipment for vacuum operation. The test resolution is 15kV, and the morphological changes of the sample are observed at different magnifications.

[0030] In the context of this invention, the method for measuring the metal element content in anion intercalation materials is ICP-MS (inductively coupled plasma atomic emission spectrometry). The sample is digested and prepared into a solution with a concentration range of 0-100 ppm for testing, and then the test results are converted into the actual concentration.

[0031] In the context of this invention, the average thickness of the anionic conductive material is measured by transmission electron microscopy. The specific test method is as follows: the sample is dissolved in ethanol and dispersed evenly by ultrasonication. The dispersed solution is dropped onto a microgrid copper mesh, dried, and then transferred to the instrument for observation at different magnifications. The average thickness of the carbon layer in different regions is taken as the final average thickness.

[0032] In the context of this invention, the ultraviolet-visible spectrophotometric measurement method employs a full-wavelength scanning method with a scanning range of 200-800 nm and a sampling interval of 4 h.

[0033] In the context of this invention, the anion content in the anion intercalation material can be determined using ion chromatography and organic elemental analysis. Ion chromatography can determine nitrate, chloride, sulfate, and phosphate ions. Specifically, the solid is dissolved in acid to prepare a solution with a concentration of 0-50 ppm, which is then introduced into a chromatographic column for testing. Organic elemental analysis can determine the concentration of carbonate ions. The precursor sample is heated to 900°C in a pure oxygen environment, and the generated gas is separated by a chromatographic column and the carbon content is obtained by passing it through a TCD detector. The carbonate ion content is then deduced from this carbon content.

[0034] Unless otherwise specified, all percentages, parts, ratios, etc. mentioned in this instruction manual are based on weight, and the pressure is gauge pressure.

[0035] In the context of this invention, any two or more embodiments or aspects of this invention can be arbitrarily combined, and the resulting technical solutions are part of the original disclosure of this specification and also fall within the protection scope of this invention.

[0036] According to one embodiment of the present invention, a core-shell structured catalytic material is disclosed. According to the present invention, the core-shell structured catalytic material comprises an anion-modified material as a substrate and an anion-conductive material supported on the anion-modified material. The inventors of the present invention have discovered that the anion-modified substrate material can effectively suppress the adsorption of chloride ions while the oxygen evolution reaction occurs. Its outer carbon layer structure protects the inner anion-modified substrate material and simultaneously improves the overall conductivity of the catalyst, enhancing its adsorption of target hydroxide ions, maximizing the potential difference between the oxygen evolution reaction and the chloride evolution reaction, thereby achieving highly efficient selection of hydroxide ions and improving its activity, selectivity, and stability under chloride-containing water electrolysis hydrogen production conditions. Without any theoretical limitations, the inventors of the present invention believe that the core-shell structure can be extended to applications in chloride-containing or chloride-free water electrolysis hydrogen production conditions, and its core-shell structure itself can also serve as an active catalytic material for conventional water electrolysis hydrogen production.

[0037] According to one embodiment of the present invention, the anion-modified material is selected from at least one of anion-intercalated materials, sulfides, phosphides, and nitrides. According to the present invention, the anions in the structure of the anion-intercalated material can repel and inhibit chloride ion adsorption during the reaction process, while also acting as a catalyst for the oxygen evolution reaction. The sulfides, phosphides, and nitrides form anion-intercalated intermediates during the reaction process, which on the one hand improve the electronic structure of the catalyst to enhance the oxygen evolution catalytic activity, and on the other hand, the formation of anion-intercalated intermediates inhibits chloride ion adsorption, thereby solving the side reaction of chloride ions on the anode side. More specifically, as the anion-modified material, anion-intercalated layered metal hydroxides, anion-intercalated layered bimetallic hydroxides (LDHs), or chloride-intercalated LDHs are preferred, chloride-intercalated hydrotalcites are more preferred, and chloride-intercalated nickel-iron-based hydrotalcites are particularly preferred. More specifically, the average chemical composition of the anion-intercalated material can be expressed by the structural formula [A]. 1- x B x (OH)2]Y n- x / nThe expression ·mH2O is schematically represented, where A is at least one metallic element selected from nickel, cobalt, manganese, copper, zinc, zirconium, and magnesium, preferably nickel, cobalt, manganese, and copper; B is at least one metallic element selected from iron, chromium, and aluminum, preferably at least one metallic element selected from iron and aluminum, provided that A and B are metals with different valence states; x is any value from 0.1 to 0.65 (preferably 0.15 to 0.37); Y represents an interlayer anion (e.g., at least one selected from chloride, carbonate, sulfate, nitrate, and phosphate ions, preferably chloride); n is an integer of 1, 2, or 3 (preferably 1); and m is 0.2 to 6 (preferably 0.3 to 1). The inventors of this invention have discovered that the anionic intercalated hydrotalcite structure itself can act as a catalyst for the oxygen evolution reaction, and its anionic intercalation modification can increase the interlayer spacing, which is beneficial for OH-. - The diffusion and desorption of reaction products such as oxygen enhance the mass transfer rate. Simultaneously, the change in interlayer spacing alters the local electronic environment of the metal active centers, thus improving catalytic activity. The anionic intercalated hydrotalcite structure, particularly the chloride ion intercalation structure, can also repel chloride ions during catalysis, preventing chloride ion accumulation on the catalyst surface. It can also be assembled with the cathode, membrane, and anode to form an electrolyzer for hydrogen production. Therefore, it can be used as both a catalyst and a chloride ion barrier material, achieving a dual-function catalytic and inhibitory catalytic effect.

[0038] According to one embodiment of the present invention, depending on the specific application of the core-shell structured catalytic material, the anionic modified material may contain at least one (preferably at least two) metallic elements selected from nickel, iron, cobalt, manganese, aluminum, copper, zinc, chromium, zirconium, and magnesium, preferably at least two metallic elements selected from nickel, iron, cobalt, manganese, chromium, and aluminum. It should be noted that the metallic elements in the anionic modified material refer to the metallic elements constituting the anionic modified material; the final anionic modified material may also contain metallic elements from other sources (such as those provided by intercalating agents). Furthermore, depending on the specific application of the core-shell structured catalytic material, particularly for seawater electrolysis, the anions used as the anionic modified material may specifically include at least one selected from sulfate ions, carbonate ions, nitrate ions, phosphate ions, and chloride ions, preferably chloride ions. As a specific example of dosage, for instance, based on a total weight of 100 wt% of the anionic modified material, the total content of the metal elements is 55-90 wt% (preferably 65-85 wt%), and the content of the anions is 2-5 wt% (preferably 3.5-4.8 wt%). When containing two or more of the aforementioned metal elements, the molar ratio between the different metal elements is 1:1-10:1 (preferably 1:1-6:1).

[0039] According to one embodiment of the present invention, the core-shell structured catalytic material has an average lateral dimension of 500-2000 nm (preferably 600-800 nm), an average longitudinal dimension of 1-100 nm (preferably 20-60 nm), and a specific surface area of ​​120-300 m². 2 / g, pore volume 0.35-0.55cm³ 3 / g, with an average pore size of 2-30nm.

[0040] According to one embodiment of the present invention, the anionic conductive material partially or completely coats the anionic modified material, preferably completely coating the anionic modified material. According to the present invention, the anionic conductive material can, on the one hand, act as a protective shield to maintain the stability of the internal layered structure, ensuring the structural integrity of the internal layered structure during hydrogen production; on the other hand, the anionic conductive material can effectively improve the overall conductivity of the catalyst, increase the electron and ion transport rate in the electrocatalytic reaction, and accelerate the reaction rate; furthermore, the anionic conductive material can improve the adsorption of hydroxide ions by the catalyst, improve the oxygen evolution reaction efficiency, and thus increase the potential difference between the oxygen evolution reaction and the chlorine evolution reaction, achieving a highly efficient oxygen evolution selective catalytic process. As for the degree of coating, the average thickness of the anionic conductive material is 0.5-50 nm (preferably 1-20 nm), or the weight ratio of the anionic modified material to the anionic conductive material is 10-2000 (preferably 30-1500). The inventors of this invention have discovered that if the thickness of the anionic conductive material is too thin, it will not be able to support the internal catalyst layer, and the improvement in the overall conductivity of the catalyst will be limited, resulting in limited improvement in the selectivity of the oxygen evolution reaction. If the thickness of the anionic conductive material is too thick, it will increase the ion transport path, reduce the reaction rate, and completely cover the active sites of the oxygen evolution reaction, thereby reducing the overall reaction efficiency.

[0041] According to one embodiment of the present invention, the anionic conductive material comprises elemental carbon. Preferably, the elemental carbon is derived from the carbonization of organic matter. From the perspective of achieving excellent technical effects, the organic matter (see the description below for details) is substantially completely carbonized. In other words, the anionic conductive material comprises carbon-containing materials or carbon elements, and more than 98 wt% of the carbon elements exist in the form of elemental carbon. According to the present invention, the elemental carbon can serve as a conductive carrier, providing channels for the transport of electrons and ions, thereby reducing interfacial contact resistance; the elemental carbon can act as a stable framework, and its stable structure can maintain excellent corrosion resistance and strong interaction at high potentials and high current densities, thus promoting catalytic reactions; the elemental carbon can also achieve electronic structure optimization and the construction of defective active sites through doping elements, thereby improving catalytic performance. Furthermore, preferably, the anionic conductive material may also contain at least one doping element selected from nitrogen, fluorine, sulfur, boron, and phosphorus (nitrogen is preferred). As a preferred content, based on 100 wt% of the total weight of the anionic conductive material, the mass content of the doping element is 0.05-8 wt% (preferably 0.1-5 wt%), and the mass content of carbon (including elemental carbon) is 92-99.95 wt% (preferably 98-99 wt%). It should be noted that, according to the present invention, the term "anionic conductive material" refers to a material that, under the combined drive of an electric field and concentration gradient, provides a directional migration channel for anions required or generated in the electrocatalytic reaction, thereby completing the ion transport process in the entire electrolysis reaction cycle and ensuring charge balance and the continuous progress of the reaction. Here, "anion" refers to any anion, not limited to the "anion" in the anionic modified material. Preferably, the ionic conductivity of the anionic conductive material is 0.01-10 S / cm (preferably 0.05-1 S / cm).

[0042] According to one embodiment of the present invention, the hydroxide ion throughput of the core-shell structured catalytic material can be evaluated by the following formula. Since the ineffective migration of chloride ions will induce ineffective current, resulting in a decrease in current efficiency, its chloride ion blocking rate can be determined by the current efficiency in conjunction with the hydroxide ion throughput. That is, the hydrogen production and current value are tested under the conditions of 20wt% alkaline solution and 20wt% alkaline seawater at the same fixed current density. Let Q0 be the measured hydrogen production under the condition of 20wt% alkaline seawater, Q1 be the measured hydrogen production under the condition of alkaline solution, I0 be the current value under the condition of 20wt% alkaline seawater, I1 be the measured current value under the condition of alkaline solution, Q0 / Q1 be 0.98-1.0 (preferably 0.99-1.0), and I0 / I1 be 0.98-1.0 (preferably 0.99-1.0).

[0043] According to one embodiment of the present invention, the anion-modified material has an average lateral dimension of 500-2000 nm (preferably 600-800 nm), an average longitudinal dimension of 1-800 nm (preferably 20-800 nm), and an interlayer spacing d(003) of 0.75-0.9 nm.

[0044] According to one embodiment of the present invention, a method for manufacturing a core-shell structured catalytic material is also provided. According to the present invention, the manufacturing method can be used to manufacture the core-shell structured catalytic material of the present invention.

[0045] According to one embodiment of the present invention, the manufacturing method includes the step of providing an anionic intercalation material, referred to as the providing step. Specifically, in the providing step, at least two metal salts are subjected to an intercalation reaction with an anionic intercalating agent to obtain the anionic intercalation material.

[0046] According to one embodiment of the present invention, the operating conditions of the intercalation reaction include: in the presence of a solvent, the pH value of the reaction system is 9-13, the reaction temperature is 110-200°C, the reaction time is 5-20 h, and the reaction pressure is 0.8-2 MPaG.

[0047] According to one embodiment of the present invention, the weight ratio of the at least two metal salts to the anionic intercalating agent is 1:0.4-4 (preferably 1:0.8-2.5). Furthermore, when at least two of the metal salts are included, the weight ratio between the different metal salts is 0.23-31 (preferably 0.7-3.5). Moreover, the weight percentage of the solid to the solvent is generally 0-10%, but the present invention is not limited thereto.

[0048] According to one embodiment of the present invention, the metal of the metal salt is selected from at least two of iron, cobalt, nickel, manganese, copper, zinc, zirconium, magnesium, chromium, and aluminum, preferably from at least two of iron, cobalt, nickel, and manganese. Furthermore, the salt of the metal salt is selected from at least one of sulfates, chlorides, nitrates, and complex ionic salts.

[0049] According to one embodiment of the present invention, the anionic intercalating agent is selected from at least one of sodium chloride, cobalt chloride, ferric chloride, potassium chloride, nickel chloride, cobalt chloride, manganese chloride, and ammonium chloride, and preferably selected from at least one of sodium chloride, cobalt chloride, ferric chloride, and potassium chloride.

[0050] According to one embodiment of the present invention, the solvent is selected from at least one of water and water-soluble organic solvents, preferably water or an ethanol / water mixture.

[0051] According to one embodiment of the present invention, the manufacturing method includes the step of contacting a carbon precursor and an optional dopant precursor with the anion intercalation material, referred to as the loading step, to obtain a composite precursor.

[0052] According to one embodiment of the invention, in the loading step, the carbon precursor is selected from at least one of monosaccharides, polysaccharides, thermoplastic resins, and thermosetting resins, preferably from at least one of glucose, sucrose, phenolic resins, benzoxazine resins, and polyaniline. According to the invention, from the perspective of method operability (e.g., solvent solubility), resin precursors are generally used in the form of their synthetic monomers, and the resin is generally not used directly unless it is solvent-soluble. For example, the benzoxazine resin can be prepared by condensation of synthetic monomers such as phenols, amine functional groups, and formaldehyde via a Mannich reaction.

[0053] According to one embodiment of the present invention, the dopant precursor is selected from at least one soluble compound containing the dopant element. Generally, the soluble compound is soluble in at least one solvent selected from water, methanol, ethanol, ethylenediamine, acetone, and N,N-dimethylformamide. More specifically, examples of soluble compounds containing the dopant element include at least one selected from glucose, fructose, and sucrose, preferably at least one selected from glucose and sucrose.

[0054] According to one embodiment of the present invention, the operating conditions of the loading step include: in the presence of a solvent, a reaction time of 0.1-25 h, a reaction temperature of 0-90 °C, and a stirring speed of 200-1000 r / min.

[0055] According to one embodiment of the present invention, the solvent is selected from at least one of water and water-soluble organic solvents, preferably selected from at least one of water, methanol, ethanol, ethylenediamine, acetone, and N,N-dimethylformamide.

[0056] According to one embodiment of the present invention, in the loading step, the weight ratio of the dopant precursor to the carbon precursor is 0.05-3 (preferably 0.5-2.2). Furthermore, the weight ratio of the carbon precursor to the anion intercalation material is 0.05-8 (preferably 0.5-6). Moreover, the amount of solvent to anion intercalation material used is, for example, 1:5-20 (preferably 1:8-13), but the present invention is not limited thereto.

[0057] According to one embodiment of the present invention, the manufacturing method includes the step of: calcining the composite precursor to convert substantially all (e.g., more than 98 wt% of the total amount) of the carbon precursor into elemental carbon, referred to as the calcination step, to obtain the core-shell structured catalytic material.

[0058] According to one embodiment of the present invention, the operating conditions of the calcination step include: a calcination temperature of 300-800°C and a calcination time of 2-10 hours under a non-oxidizing gas atmosphere. Here, the non-oxidizing gas atmosphere may be selected from at least one of nitrogen, argon, hydrogen, and ammonia, preferably nitrogen and / or ammonia.

[0059] According to one embodiment of the present invention, a layered electrode is also disclosed, comprising a cathode, an anion exchange membrane, and an anode in sequence. Apart from the details described below, anything conventionally known in the art regarding layered electrodes (or thin-film electrodes) is directly applicable to the present invention and will not be repeated here.

[0060] According to one embodiment of the present invention, an anion-selective barrier material layer is disposed at at least one location: on the outside of the cathode, between the cathode and the anion exchange membrane, and between the anode and the anion exchange membrane. Preferably, the anion-selective barrier material layer is disposed on the outside of the cathode. According to the present invention, the anion-selective barrier material can be the core-shell structured catalytic material of the present invention. According to this embodiment of the present invention, when the layered electrode is used, especially in seawater electrolysis applications, seawater first contacts the anion-selective barrier material and then contacts each electrode; this is the key to the present invention's ability to achieve the desired technical effect. Specifically, after chloride-containing water enters the electrolyzer, it first passes through a chloride ion selective barrier material, then sequentially through electrodes and membranes. The chloride ion selective barrier material is a core-shell structure of anion-modified layered electrodes wrapped with carbon layers. The carbon layer structure protects the internal catalytic layer, thus improving the stability of the chloride ion selective barrier material, and also adsorbs hydroxide and chloride ions. Simultaneously, the unique structure of the carbon layer improves the overall conductivity of the chloride ion selective barrier material, thereby reducing the reaction overpotential. The core is anion-modified composite structure with good oxygen evolution catalytic activity. Furthermore, the anion modification gives the core a certain degree of repulsion against chloride ions, preventing their accumulation and ineffective migration on the electrode surface, thus achieving selective adsorption of hydroxide ions. In addition, the chloride ion selective barrier material itself possesses electrocatalytic activity, therefore it also improves the hydrogen production efficiency.

[0061] According to one embodiment of the present invention, the cathode, the anion exchange membrane, the anode, and the anion selective blocking material layer are independently layered and stacked together in a zero-gap manner to form a whole. Here, "zero-gap" means that the chloride ion selective blocking material, cathode, exchange membrane, and anode are arranged as closely as possible in sequence. The inventors of the present invention have found that the zero-gap method can effectively shorten the ion transport path and maximize the contact area, thus resulting in higher electrolysis efficiency. Simultaneously, the zero-gap method can effectively reduce the spacing between the chambers of the electrolytic cell, achieving the goal of reducing the overall volume and weight of the electrolytic cell. If the zero-gap method is not used, the chloride ion blocking effect will not be affected, but the electrolysis efficiency will decrease, and the overall volume of the electrolytic cell may increase.

[0062] According to one embodiment of the present invention, the thickness of the cathode is 1-800 micrometers, the thickness of the anion exchange membrane is 80-1000 micrometers, the thickness of the anode is 1-800 micrometers, and the thickness of the anion selective blocking material layer is 1-800 micrometers (preferably 20-500 micrometers).

[0063] According to the present invention, the specific selection of the anode catalyst in the anode is not limited, and it can be a conventional anode catalyst in the field of layered electrodes, such as a metal element, alloy, metal or non-metal compound with corresponding activity. According to one embodiment of the present invention, the anode catalyst contains at least one of nickel (Ni), iron (Fe), cobalt (Co), manganese (Mn), molybdenum (Mo), aluminum (Al), and alloys of any two or more of these components. By selecting the above-mentioned highly active and selective anode catalyst, the oxygen evolution reaction can still occur to the maximum extent at the anode even in the presence of some chloride ions, thereby improving hydrogen production efficiency. Specifically, the anode catalyst can be one or more of the elements, alloys, nitrides, phosphides, oxides, and hydroxides of Ni, Fe, Co, Mn, Mo, and Al. Generally, the loading of the anode catalyst in the anode is 1.0-10.0 mg / cm³. 2 (Preferred concentration: 4.5-9.0 mg / cm³) 2 ).

[0064] The present invention does not limit the specific selection of the cathode catalyst in the cathode, and it can be a conventional cathode catalyst in the field of water electrolysis for hydrogen production, such as a metal element, alloy, metal or non-metal compound with corresponding activity. According to one embodiment of the present invention, the cathode catalyst contains at least one of nickel, iron, cobalt, manganese, and alloys of any two or more of these components. Specifically, the cathode catalyst can be one or more of the elements, alloys, nitrides, phosphides, oxides, and hydroxides of Ni, Fe, Co, and Mn. Generally, the loading of the cathode catalyst in the cathode is 0.5-8.0 mg / cm³. 2 (Preferred concentration: 4.5-7.5 mg / cm³) 2 ).

[0065] According to the present invention, the specific selection of the anion exchange membrane is not limited. In some embodiments, the functional groups of the anion exchange membrane are selected from at least one of primary amines, secondary amines, tertiary amines, quaternary amines, and aromatic amines. The function of the functional groups is to modify the polymer backbone to achieve directional selection of anions. In some embodiments, based on the matrix skeleton material, the anion exchange membrane can be a fluoropolymer membrane such as polytetrafluoroethylene or fluorinated poly(aryl ethers), or a non-fluorocarbon polymer membrane such as polysulfones, polyphenylene ethers, polyaryl ether ketones, polyvinylpyridines, and polynorbornene. By employing anion exchange membranes, anions can pass through directionally, while cations are restricted, resulting in better ionic conductivity. Combined with the function of the anion-selective barrier material layer, chloride ions cannot be transported through the membrane material, thereby further suppressing the competitive precipitation of chloride ions at the anode.

[0066] According to one embodiment of the present invention, the loading of anion-selective blocking material in the anion-selective blocking material layer is generally 0.5-8.0 mg / cm³. 2 (Preferred dosage: 3.0-6.0 mg / cm³) 2 ).

[0067] According to one embodiment of the present invention, a method for manufacturing a layered electrode is also provided, comprising the following steps: (1) coating a cathode slurry containing a cathode catalyst onto one side of an anion exchange membrane and performing a first hot-pressing treatment to form a cathode on one side of the anion exchange membrane; (2) coating an anode slurry containing an anode catalyst onto the other side of the anion exchange membrane and performing a second hot-pressing treatment to form an anode on the other side of the anion exchange membrane; (3) coating an anion selective barrier material slurry containing anion selective barrier material onto at least one location, including the outer side of the cathode, between the cathode and the anion exchange membrane, and between the anode and the anion exchange membrane, and then performing a third hot-pressing treatment.

[0068] According to the present invention, the order of steps (1), (2), and (3) is not limited, as long as the adjacent catalyst layer is prepared before the anion-selective barrier material layer is prepared. For example, when the anion-selective barrier material layer is disposed on the outside of the cathode, the cathode can be prepared before the anion-selective barrier material layer is prepared.

[0069] According to one embodiment of the present invention, in step (1), the conditions for the first hot pressing treatment include: a temperature of 120-300°C, a pressure of 2-15 MPa, and a time of 1-30 min.

[0070] According to one embodiment of the present invention, in step (2), the conditions for the second hot pressing treatment include: a temperature of 120-300°C, a pressure of 2-15 MPa, and a time of 1-30 min.

[0071] According to one embodiment of the present invention, in step (3), the conditions of the third hot pressing treatment include: temperature of 120-300℃, pressure of 2-15MPa, and time of 1-30min.

[0072] According to the present invention, those skilled in the art will understand that when the anion selective barrier material layer is located between the anode and the exchange membrane and / or between the cathode and the exchange membrane, if the hot pressing method is used for preparation, the above method can be followed. The only difference is that the preparation order of each layer is different, which will not be elaborated here.

[0073] According to one embodiment of the present invention, the above-mentioned layered electrode is prepared by a transfer method. When the anion-selective blocking material layer is disposed on the outside of the anode and / or cathode, the preparation method of the layered electrode specifically includes:

[0074] a. An anode slurry containing an anode catalyst is coated onto a first transfer film, and a cathode slurry containing a cathode catalyst is coated onto a second transfer film. The first transfer film carrying the anode slurry and the second transfer film carrying the cathode slurry are placed on both sides of an anion exchange membrane, and an anode and a cathode are formed on both sides of the exchange membrane by a fourth hot-pressing treatment.

[0075] b. Apply an anion-selective barrier material slurry containing a directionally selected catalyst onto a third transfer film, place the third transfer film containing the anion-selective barrier material slurry on the outside of the anode and / or cathode, and transfer it to the outside of the anode and / or cathode through a fifth hot-pressing process.

[0076] According to one embodiment of the present invention, in step a, the conditions for the fourth hot pressing include: a temperature of 150-300°C, a pressure of 5-18 MPa, and a time of 1-10 min.

[0077] According to one embodiment of the present invention, in step b, the conditions for the fifth hot pressing include: a temperature of 150-300°C, a pressure of 10-18 MPa, and a time of 1-20 min.

[0078] According to one embodiment of the present invention, in step b, the first transfer film, the second transfer film, and the third transfer film can each be independently selected from any one of polytetrafluoroethylene film, polyimide film, polydimethylsiloxane film, silicone rubber sheet, and aluminum foil. For ease of operation, according to one embodiment of the present invention, the first transfer film, the second transfer film, and the third transfer film are selected in the same way.

[0079] According to one embodiment of the present invention, the cathode paste may further contain a first solvent and a first binder, the anode paste may further contain a second solvent and a second binder, and the anion selective barrier material paste may further contain a third solvent and a third binder.

[0080] According to one embodiment of the present invention, the first adhesive, the second adhesive and the third adhesive are each independently selected from Nafion solution and / or PTFE solution.

[0081] According to one embodiment of the present invention, the first solvent, the second solvent, and the third solvent are each independently selected from at least one of deionized water, ethylene glycol, isopropanol, and glycerol.

[0082] According to one embodiment of the present invention, the mass ratio of the cathode catalyst, the first binder and the first solvent is 1:1.5-30:11-70, more preferably 1:4-20:11-50.

[0083] According to one embodiment of the present invention, the mass ratio of the anode catalyst, the second binder, and the second solvent is 1:1.5-30:10-70, more preferably 1:4-20:10-50.

[0084] According to one embodiment of the present invention, the mass ratio of the directional catalyst, the third binder and the third solvent is 1:1.5-30:11-70, more preferably 1:4-20:11-50.

[0085] According to the present invention, it is understood that when the anion selective barrier material layer is located between the anode and the anion exchange membrane and / or between the cathode and the anion exchange membrane, if the transfer method is used for preparation, the above method can be followed. The only difference is that the preparation order of each layer is different, which will not be elaborated here.

[0086] According to one embodiment of the present invention, the coating method can be spraying or coating, and there is no particular limitation.

[0087] According to one embodiment of the present invention, a method for electrolyzing chloride-containing water (preferably seawater) is also provided, comprising the step of electrolyzing the chloride-containing water using the layered electrode of the present invention. Except as specifically described below, all matters or practices conventionally known in the art related to seawater electrolysis are directly applicable to the present invention and will not be repeated here.

[0088] According to one embodiment of the present invention, the electrolysis method includes the steps of: contacting chloride-containing water with an anion-selective barrier material to obtain treated water, and then contacting the treated water with an electrode to undergo a water decomposition reaction to obtain oxygen and hydrogen. According to this embodiment of the present invention, the chloride-containing water is first contacted with the anion-selective barrier material and then with the electrode; this is the key to the present invention's ability to achieve the desired technical effect. Specifically, after chloride-containing water enters the electrolyzer, it first passes through a chloride ion selective barrier material, then sequentially through electrodes and membranes. The chloride ion selective barrier material is a core-shell structure of anion-modified layered electrodes wrapped with carbon layers. The carbon layer structure protects the internal catalytic layer, thus improving the stability of the chloride ion selective barrier material, and also adsorbs hydroxide and chloride ions. Simultaneously, the unique structure of the carbon layer improves the overall conductivity of the chloride ion selective barrier material, thereby reducing the reaction overpotential. The core is anion-modified composite structure with good oxygen evolution catalytic activity. Furthermore, the anion modification gives the core a certain degree of repulsion against chloride ions, preventing their accumulation and ineffective migration on the electrode surface, thus achieving selective adsorption of hydroxide ions. In addition, the chloride ion selective barrier material itself possesses electrocatalytic activity, therefore it also improves the hydrogen production efficiency.

[0089] According to one embodiment of the present invention, the operating conditions of the decomposition reaction include: operating temperature: 20-90℃, operating pressure: 0-2.5MPaG, and operating voltage: 1.7-2.2V.

[0090] According to a preferred embodiment of the present invention, the treated water is brought into contact with the cathode and the anode sequentially. In this case, the chloride-containing water is located outside the cathode (and also outside the anion-selective blocking material), i.e., the chloride-containing water is supplied from one side of the cathode. According to this embodiment of the present invention, the treated water is brought into contact with the anode last. The inventors of the present invention have discovered that when the chloride-containing water passes through the chloride-selective blocking material before entering the cathode, due to the directional selective adsorption effect of the chloride-selective blocking material, it can be ensured that chloride ions in the system are concentrated on the cathode side, which can both ensure the ineffective migration of chloride ions and fundamentally block the chloride evolution side reaction on the anode side.

[0091] According to one embodiment of the present invention, an electrolysis apparatus for chloride-containing water is also provided, comprising an electrolysis cell for containing chloride-containing water and the layered electrode of the present invention. According to the present invention, apart from the layered electrode, other aspects and considerations concerning seawater electrolysis apparatus in the art are directly applicable to the present invention, and will not be elaborated further here.

[0092] Example

[0093] The present invention will be further described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0094] Example 1

[0095] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 752g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.3MPa for 6h. After washing and drying, chloride ion modified nickel-iron hydrotalcite is obtained. It is placed in 28g of resorcinol, 14L of formaldehyde, 10.5L of ethylenediamine and 2.8L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stirred at 600r / min for 24h at 25℃. Then, it is calcined at 600℃ for 10h under an ammonia atmosphere so that more than 98wt% of the total amount is converted into elemental carbon to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0096] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 / g, with an average pore size of 5.2nm and an interlayer spacing d(003) of 0.8nm; the anionic conductive material is a nitrogen-modified carbon layer, and based on a total weight of 100wt% of the anionic conductive material, the mass content of the nitrogen doping element is 1.5wt%, and the mass content of carbon element (including the elemental carbon) is 98.5wt%; the weight ratio of the anionic modified material to the anionic conductive material is 120:1; the thickness of the shell layer is 5nm; the core-shell structure catalytic material, wherein the ionic conductivity of the anionic conductive material is 0.8S / cm.

[0097] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0098] Figure 1 shows the morphology of the chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst. As can be seen from the figure, the core-shell catalyst has a sheet structure with sheet size of about 650 nm. The rough surface is the result of iron etching. The rough surface can improve the hydrophilicity of the catalyst and thus improve the electrocatalytic performance.

[0099] Figure 2 shows the UV-Vis spectrophotometer test results of the electrolyte after the reaction, with a scanning wavelength of 200-800 nm. As can be seen from the figure, if sodium hypochlorite is present in the solution, a peak will appear at around 300 nm. If chloride ions in the electrolyte are deposited at the anode, the generated chlorine gas will produce hypochlorite ions, which will also appear at around 300 nm. However, in the results of Figure 2, the electrolyte after the reaction in Example 1 did not show any peak, indicating that no chloride evolution side reaction occurred at the anode. This shows that Example 1 can effectively suppress the chloride ion side reaction at the anode.

[0100] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0101] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0102] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0103] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0104] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0105] Example 2

[0106] (1) Take 555 cobalt chloride, 278g ferric chloride, 60g potassium chloride and 3.8kg sodium hydroxide and put them into a 70L reactor and stir evenly. React at 110℃, pH 14 and pressure 1.0MPa for 20h. After washing and drying, chloride-modified iron-cobalt hydrotalcite is obtained. It is placed in a 35mg / mL glucose aqueous solution and stirred at 800r / min at 80℃ for 10h. Then it is transferred to the downstream of a tube furnace and 2.2g sodium hypophosphite is placed upstream. It is calcined at 700℃ for 10h under a nitrogen atmosphere so that more than 98wt% of the total amount is converted into elemental carbon to obtain a core-shell catalyst. The core-shell catalyst has a phosphorus-doped carbon layer as the shell and a chloride-modified iron-cobalt hydrotalcite as the core.

[0107] The chloride ion selective blocking material contains 82 wt% cobalt and iron, 3.8 wt% chloride ions, and a cobalt-iron molar ratio of 4:1. It has a layered structure with an average lateral dimension of 700 nm, an average longitudinal dimension of 25 nm, and a specific surface area of ​​135 m². 2 / g, pore volume is 0.41cm 3 / g, with an average pore size of 5.3nm and an interlayer spacing d(003) of 0.82nm; the anionic conductive material is a phosphorus-modified carbon layer, and based on a total weight of 100wt% of the anionic conductive material, the mass content of the doping element is 0.9wt%, and the mass content of carbon element (including the elemental carbon) is 99.1wt%; the weight ratio of the anionic modified material to the anionic conductive material is 100:1; wherein the average thickness of the anionic conductive material is 15nm, and the ionic conductivity is 0.76S / cm.

[0108] The chloride ion selective blocking material has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0109] (2) 3.1g of nickel-cobalt-based anode catalyst and 21g of 20% Nafion solution were added to 194g of ethylene glycol aqueous solution (obtained by mixing ethylene glycol and water at a volume ratio of 4:1) and ultrasonically mixed to prepare an anode slurry. 4.7g of nickel alloy-based cathode catalyst b and 19g of 20% Nafion solution were added to 118g of ethylene glycol aqueous solution (obtained by mixing ethylene glycol and water at a volume ratio of 4:1) and ultrasonically mixed to prepare a cathode slurry. The anode slurry was coated onto one polyimide film, and the cathode slurry was coated onto another polyimide film. The polyimide film carrying the cathode slurry and the polyimide film carrying the anode slurry were placed on both sides of the exchange membrane a, respectively. Then, the membrane was hot-pressed at 150℃ and 18MPa for 10min to form an anode catalyst layer and a cathode catalyst layer on both sides of the membrane, respectively. The loading of the anode catalyst in the anode catalyst layer was 4.5mg / cm³. 2 The loading of the cathode catalyst in the cathode catalyst layer is 7.5 mg / cm³. 2 ;

[0110] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. The model is EVE Energy W-75, and the thickness of the exchange membrane is 75 micrometers.

[0111] (3) A directional selective catalytic slurry was prepared by uniformly mixing 1.9g of the core-shell catalyst obtained in step (1), 11.2g of 20% Nafion solution, and 30g of ethylene glycol aqueous solution (obtained by mixing ethylene glycol and water at a volume ratio of 4:1). This slurry was coated onto the surface of a polyimide film and placed on the side of the film carrying the cathode catalyst layer. The film was then hot-pressed at 300℃ and 10MPa for 20min to form a chloride ion selective barrier material. The loading of the core-shell catalyst in the chloride ion selective barrier material was 3mg / cm³. 2 Ultimately, the product is obtained.

[0112] (4) The electrolysis device obtained in (3) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0113] Example 3

[0114] (1) Take 833g of nickel chloride, 208g of manganese chloride, 4.2kg of urea and 434g of potassium chloride and put them into a 70L reactor and stir evenly. React at 200℃, pH 9.5 and pressure 1.4MPa for 6h. After washing and drying, chloride-modified nickel-manganese hydrotalcite is obtained. It is placed in 56g of resorcinol, 24L of formaldehyde, 15.3L of ethylenediamine and 5.6L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stirred at 25℃ and 700r / min for 20h. Then it is transferred to the downstream of the tube furnace and 2g of boron oxide is placed upstream. It is calcined at 800℃ for 5h under nitrogen atmosphere to obtain a core-shell catalyst so that more than 98wt% of the total amount is converted into elemental carbon. The core-shell catalyst has a boron-doped carbon layer as the shell and a chloride-modified nickel-manganese hydrotalcite as the core.

[0115] The total nickel-manganese content in the chloride ion selective blocking material layer is 78 wt%, the chloride ion content is 4.2 wt%, and the molar ratio of nickel to manganese is 4:1. It has a layered structure with an average lateral dimension of 720 nm, an average longitudinal dimension of 28 nm, and a specific surface area of ​​126 m². 2 / g, pore volume 0.45cm 3 The anionic conductive material has an average pore size of 5.5 nm and an interlayer spacing d(003) of 0.84 nm. The anionic conductive material contains a boron-modified carbon layer, and based on a total weight of 100 wt% of the anionic conductive material, the mass content of the doping element is 1.6 wt%, and the mass content of carbon element (including the elemental carbon) is 98.4 wt%. The weight ratio of the anionic modified material to the anionic conductive material is 160:1. The anionic conductive material has an average thickness of 9 nm and an ionic conductivity of 0.85 S / cm.

[0116] (2) 3.8g of nickel-iron-based anode catalyst and 60g of 5% Nafion solution were added to 63g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 4:1) and ultrasonically mixed to prepare an anode slurry. 4.1g of nickel alloy-based cathode catalyst a and 4.2g of 5% Nafion solution were added to 181g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 1:1) and ultrasonically mixed to prepare a cathode slurry. Both slurries were coated onto both sides of a 25*25cm exchange membrane and subjected to hot-pressing treatment at a temperature of 150℃, a pressure of 15MPa, and a time of 10min. The loading of the anode catalyst in the anode catalyst layer was 6mg / cm³. 2 The loading of the cathode catalyst in the cathode catalyst layer is 6.5 mg / cm³. 2 ;

[0117] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0118] (3) Subsequently, 3.8g of the core-shell catalyst obtained in step (1), 108g of 5% Nafion solution, and 104g of ethylene glycol aqueous solution (obtained by mixing ethylene glycol and water at a volume ratio of 3:1) were mixed evenly to prepare a directional selective catalytic slurry. This slurry was then coated onto the membrane side carrying the cathode catalyst layer and hot-pressed at 300℃ and 10MPa for 5min to form a chloride ion selective barrier material layer. The loading of the core-shell catalyst was 6mg / cm³. 2 Q0 / Q1 is 0.997, and I0 / I1 is 0.997.

[0119] (4) The electrolysis device obtained in (3) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0120] Example 4

[0121] (1) Take 1 kg of nickel nitrate, 277 g of ferric nitrate and 2.2 kg of urea and put them into a 70 L reactor and stir evenly. React at 150 °C, pH 9 and pressure 1.3 MPa for 6 h. After washing and drying, intermediate powder is obtained. Transfer the intermediate powder to 0.2 mol / L thiourea solution and react at 160 °C for 10 h. After washing and drying, nickel-iron-based sulfide is obtained. Then place it in 28 g of resorcinol, 2 L of formaldehyde, 10 L of ethylenediamine and 2.7 L of ethanol aqueous solution (the volume ratio of water to ethanol is 7:3) and stir at 25 °C and 500 r / min for 24 h. Then calcine at 600 °C for 10 h under an ammonia atmosphere so that more than 98 wt% of the total amount is converted into elemental carbon to obtain nickel-iron-based sulfide@nitrogen-modified carbon core-shell catalyst.

[0122] Based on the total weight of the chloride ion intercalated hydrotalcite@nitrogen-modified carbon core-shell catalyst, the content of the metal elements is 80% by weight, the chloride ion content is 3.5% by weight, the molar ratio of nickel to iron is 4:1, it has a layered structure, an average lateral dimension of 600 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 / g, with an average pore size of 5.0nm; the anionic conductive material is a nitrogen-modified carbon layer, and based on a total weight of 100wt% of the anionic conductive material, the mass content of the doping element is 1.4wt%, and the mass content of carbon element (including the elemental carbon) is 98.6wt%; the weight ratio of the anionic modified material to the anionic conductive material is 115:1; the average thickness of the anionic conductive material is 5nm, and the ionic conductivity is 0.82S / cm.

[0123] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.996 and an I0 / I1 ratio of 0.996.

[0124] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0125] An anion exchange membrane that allows water and anions to pass through, the functional group of which is a dimethylpiperidine ion functional group, the model of which is Versogen A80, has a thickness of 80 micrometers.

[0126] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0127] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0128] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0129] The electrolysis device and electrolysis method are the same as in Example 1, except that the chloride ion selective blocking material is a sulfide.

[0130] Example 5

[0131] (1) Take 1.6 kg of nickel sulfate, 174 g of ferric nitrate and 1.1 kg of sodium hydroxide and put them into a 70 L reactor and stir evenly. React at 200 °C, pH 14 and pressure 1.1 MPa for 20 h. After washing and drying, obtain chloride ion modified nickel-iron hydrotalcite. Put it into 28 g of resorcinol, 14 L of formaldehyde, 10.5 L of ethylenediamine and 2.8 L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stir at 25 °C and 650 r / min for 24 h. Then calcine at 600 °C for 10 h under an ammonia atmosphere so that more than 98 wt% of the total amount is converted into elemental carbon to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0132] The chloride ion selective blocking material contains 80 wt% nickel-iron and 3.3 wt% sulfate ions, with a molar ratio of 5:1. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 / g, with an average pore size of 5.2nm and an interlayer spacing d(003) of 0.8nm; chloride-modified nickel-iron hydrotalcite, and based on the total weight of the anionic conductive material as 100wt%, the mass content of the doped elements is 1.3wt%, and the mass content of carbon (including the elemental carbon) is 98.7wt%; the weight ratio of the anionic modified material to the anionic conductive material is 125:1; the average thickness of the anionic conductive material is 5nm; and the ionic conductivity is 0.78S / cm.

[0133] The chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.995 and an I0 / I1 ratio of 0.995.

[0134] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0135] An anion exchange membrane that allows water and anions to pass through, the functional group of which is a dimethylpiperidine ion functional group, the model of which is Versogen A80, has a thickness of 80 micrometers.

[0136] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0137] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0138] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0139] The electrolysis apparatus and electrolysis method are the same as in Example 1, except that the anion-modifying material is sulfate ion-intercalated nickel-iron-based hydrotalcite.

[0140] Example 6

[0141] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 300g of sodium chloride and put them into a 70L reactor and stir evenly. React at 140℃, pH 9.5 and pressure 1.1MPa for 5h. After washing and drying, obtain chloride ion modified nickel-iron hydrotalcite. Put it into 28g of resorcinol, 14L of formaldehyde, 10.5L of ethylenediamine and 2.8L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stir at 25℃ and 550r / min for 24h. Then calcine at 600℃ for 10h under ammonia atmosphere so that more than 98wt% of the total amount is converted into elemental carbon to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0142] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 The anionic conductive material has an average pore size of 5.2 nm and an interlayer spacing d(003) of 0.8 nm. The anionic conductive material is a nitrogen-modified carbon layer, and based on the total weight of the anionic conductive material of 100 wt%, the mass content of the doping element is 0.05-8 wt% (preferably 0.1-5 wt%), and the mass content of carbon element (including the elemental carbon) is 92-99.95 wt% (preferably 99.5-99.9 wt%). The weight ratio of the anionic modified material to the anionic conductive material is 120:1. The anionic conductive material has an average thickness of 5 nm and an ionic conductivity of 0.8 S / cm.

[0143] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.99 and an I0 / I1 ratio of 0.99.

[0144] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0145] An anion exchange membrane that allows water and anions to pass through, the functional group of which is a dimethylpiperidine ion functional group, the model of which is Versogen A80, has a thickness of 80 micrometers.

[0146] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0147] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0148] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0149] The electrolysis apparatus and electrolysis method are the same as in Example 1, except that the anion content is 1 wt%.

[0150] Example 7

[0151] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.5kg of urea and 1.0kg of sodium chloride and put them into a 70L reactor and stir evenly. React at 200℃, pH 9 and pressure 1.4MPa for 25h. After washing and drying, obtain chloride ion modified nickel-iron hydrotalcite. Put it into 28g of resorcinol, 14L of formaldehyde, 10.5L of ethylenediamine and 2.8L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stir at 25℃ and 650r / min for 24h. Then calcine at 600℃ for 10h under ammonia atmosphere so that more than 98wt% of the total amount is converted into elemental carbon to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0152] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 / g, with an average pore size of 5.2nm and an interlayer spacing d(003) of 0.8nm; the anionic conductive material is a nitrogen-modified carbon material, and based on a total weight of 100wt% of the anionic conductive material, the mass content of the doping element is 1.45wt%, and the mass content of carbon element (including the elemental carbon) is 98.55wt%; the weight ratio of the anionic modified material to the anionic conductive material is 122:1; the average thickness of the anionic conductive material is 5nm, and the ionic conductivity is 0.75S / cm.

[0153] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0154] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0155] An anion exchange membrane that allows water and anions to pass through, the functional group of which is a dimethylpiperidine ion functional group, the model of which is Versogen A80, has a thickness of 80 micrometers.

[0156] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0157] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0158] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0159] The electrolysis apparatus and electrolysis method are the same as in Example 1, except that the anion content is 6 wt%.

[0160] Example 8

[0161] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 434g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.2MPa for 6h. After washing and drying, chloride ion modified nickel-iron hydrotalcite is obtained. Place it downstream of a tube furnace and place 1.8kg of melamine upstream. Heat it to 300℃ at 5℃ / min and then to 800℃ at 2℃ / min. Calcine it at 800℃ for 3h under an ammonia atmosphere to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0162] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 The anionic conductive material has an average pore size of 5.2 nm and an interlayer spacing d(003) of 0.8 nm. The anionic conductive material is a nitrogen-modified carbon material, and based on a total weight of 100 wt% of the anionic conductive material, the mass content of the doping element is 1.2 wt%, and the mass content of carbon element (including the elemental carbon) is 98.8 wt%. The weight ratio of the anionic modified material to the anionic conductive material is 220:1. The anionic conductive material has an average thickness of 3.2 nm and an ionic conductivity of 0.7 S / cm.

[0163] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0164] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0165] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0166] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0167] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0168] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0169] The electrolysis device and electrolysis method are the same as in Example 1, except that the carbon content is 70 wt% (the other 30% is its nitrogen conductive material).

[0170] Example 9

[0171] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 752g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.3MPa for 6h. After washing and drying, chloride ion modified nickel-iron hydrotalcite is obtained. Place it in a tube furnace and pass a mixture of 20% methane and 80% argon. Calcine at 650℃ for 6h to obtain chloride ion intercalated hydrotalcite@carbon core-shell catalyst.

[0172] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 / g, with an average pore size of 5.2nm and an interlayer spacing d(003) of 0.8nm; the anionic conductive material is a nitrogen-modified carbon material, and based on a total weight of 100wt% of the anionic conductive material, the mass content of the doping element is 1.0wt%, and the mass content of carbon element (including the elemental carbon) is 99wt%; the weight ratio of the anionic modified material to the anionic conductive material is 280:1; the average thickness of the anionic conductive material is 3nm, and the ionic conductivity is 0.71S / cm.

[0173] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0174] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0175] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0176] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0177] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0178] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0179] The electrolysis device and electrolysis method are the same as in Example 1, except that the elemental carbon is not derived from the carbonization of organic matter, but is directly grown on the catalyst surface by vapor deposition.

[0180] Example 10

[0181] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 800g of urea and 600g of sodium chloride and put them into a 70L reactor and stir evenly. React at 100℃, pH 8 and pressure 0.9MPa for 12h. After washing and drying, obtain chloride ion modified nickel-iron hydrotalcite. Put it into 28g of resorcinol, 14L of formaldehyde, 10.5L of ethylenediamine and 2.8L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stir at 25℃ and 650r / min for 24h. Then calcine at 600℃ for 10h under ammonia atmosphere so that more than 98wt% of the total amount is converted into elemental carbon to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0182] The chloride ion selective blocking material contains 80 wt% nickel and 3.0 wt% iron, with a nickel-iron molar ratio of 5:1. It has a layered structure with an average lateral dimension of 630 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3The anionic conductive material has an average pore size of 5.2 nm and an interlayer spacing d(003) of 0.8 nm. The anionic conductive material is a nitrogen-modified carbon material, and based on a total weight of 100 wt% of the anionic conductive material, the mass content of the doping element is 1.25 wt%, and the mass content of carbon element (including the elemental carbon) is 98.75 wt%. The weight ratio of the anionic modified material to the anionic conductive material is 140:1. The anionic conductive material has an average thickness of 5 nm and an ionic conductivity of 0.7 S / cm.

[0183] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0184] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0185] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0186] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0187] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0188] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0189] The electrolysis device and electrolysis method are the same as in Example 1, except that the synthesis pH in step (1) is 8.

[0190] Example 11

[0191] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 752g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.3MPa for 6h. After washing and drying, obtain chloride ion modified nickel-iron hydrotalcite. Put it into 220g of resorcinol, 12L of formaldehyde, 100L of ethylenediamine and 25L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stir at 30℃ and 800r / min for 24h. Then calcine at 600℃ for 10h under ammonia atmosphere so that more than 98wt% of the total amount is converted into elemental carbon to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0192] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 The anionic conductive material has an average pore size of 5.2 nm and an interlayer spacing d(003) of 0.8 nm. The anionic conductive material is a nitrogen-modified carbon material, and based on a total weight of 100 wt% of the anionic conductive material, the mass content of the doping element is 2 wt%, and the mass content of carbon element (including the elemental carbon) is 98 wt%. The weight ratio of the anionic modified material to the anionic conductive material is 60:1. The anionic conductive material has an average thickness of 47 nm and an ionic conductivity of 0.88 S / cm.

[0193] The chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.994 and an I0 / I1 ratio of 0.994.

[0194] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0195] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0196] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0197] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0198] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0199] The electrolysis apparatus and electrolysis method are the same as in Example 1, except that the weight ratio of carbon precursor to anion intercalation material is 10.

[0200] Comparative Example 1

[0201] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 752g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.3MPa for 6h. After washing and drying, obtain chloride ion modified nickel-iron hydrotalcite and obtain chloride ion intercalated hydrotalcite catalyst.

[0202] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 / g, with an average pore size of 5.2nm and an interlayer spacing d(003) of 0.8nm;

[0203] The chloride ion intercalated hydrotalcite catalyst has a Q0 / Q1 ratio of 0.997 and an I0 / I1 ratio of 0.997.

[0204] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0205] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0206] (3) Add 3.1g of the chloride ion selective blocking material obtained in step (1) and 38g of 5% Nafion solution to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. Coat the slurry onto the cathode catalyst layer and hot-press it at 200℃ and 15MPa for 1min to form a chloride ion selective blocking material on the surface of the cathode catalyst layer. The loading of the chloride ion selective blocking material is 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0207] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst with 83g of 5% Nafion solution and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane material and subjected to hot-pressing treatment. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0208] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0209] The electrolysis apparatus and electrolysis method are the same as in Example 1, except that: it is a simple chloride ion intercalated nickel-iron-based hydrotalcite without any loaded materials.

[0210] Comparative Example 2

[0211] (1) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot pressing. The hot pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0212] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0213] (2) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 752g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.3MPa for 6h. After washing and drying, chloride ion modified nickel-iron hydrotalcite is obtained, and chloride ion intercalated hydrotalcite is obtained.

[0214] A slurry was prepared by adding 3.1 g of chloride ion-intercalated hydrotalcite and 38 g of 5% Nafion solution to 88 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1). This slurry was coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15 MPa for 1 min. Subsequently, a slurry was prepared by adding 0.1 g of activated carbon and 12 g of 5% Nafion solution to 92 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1). This slurry was coated onto the chloride ion-intercalated hydrotalcite and hot-pressed at 280℃ and 20 MPa for 5 min to obtain a chloride ion selective barrier layer. The loading of the chloride ion selective barrier material was 5 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0215] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​323 m². 2 / g, pore volume is 0.34cm 3 / g, with an average pore size of 3.4nm and an interlayer spacing d(003) of 0.83nm; the anionic conductive material is activated carbon; the weight ratio of the anionic modified material to the anionic conductive material is 30:1; the average thickness of the anionic conductive material is 20nm and the ionic conductivity is 0.05S / cm.

[0216] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0217] (3) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst with 83g of 5% Nafion solution and 59g of isopropanol. The anode slurry was coated onto the other side of the exchange membrane a material and subjected to hot pressing. The hot pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0218] (5) The electrolysis device obtained in (3) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0219] The electrolysis device and electrolysis method are the same as in Example 1, except that the load is activated carbon, not an anionic conductive material.

[0220] Comparative Example 3

[0221] (1) Take 694g of nickel nitrate, 174g of ferric nitrate and 1.85kg of urea and put them into a 70L reactor and stir evenly. React at 130℃, pH 9.5 and pressure 1.2MPa for 8h. After washing and drying, chloride ion modified nickel-iron hydrotalcite is obtained. It is placed in 28g of resorcinol, 14L of formaldehyde, 10.5L of ethylenediamine and 2.8L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stirred at 25℃ and 900r / min for 24h. Then, it is calcined at 600℃ for 10h under an ammonia atmosphere so that more than 98wt% of the total amount is converted into elemental carbon to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0222] The total nickel-iron content in the chloride ion selective blocking material is 83 wt%, with a molar ratio of nickel to iron of 5:1. It has a layered structure with an average lateral dimension of 653 nm, an average longitudinal dimension of 18 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 The anionic conductive material has an average pore size of 5.2 nm and an interlayer spacing d(003) of 0.78 nm. The anionic conductive material is a nitrogen-modified carbon material, and based on a total weight of 100 wt% of the anionic conductive material, the mass content of the doping element is 1.4 wt%, and the mass content of carbon element (including the elemental carbon) is 98.6 wt%. The weight ratio of the anionic modified material to the anionic conductive material is 118:1. The anionic conductive material has an average thickness of 5.2 nm and an ionic conductivity of 0.79 S / cm.

[0223] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0224] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0225] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0226] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0227] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0228] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0229] The electrolysis apparatus and electrolysis method are the same as in Example 1, except that nickel-iron-based hydrotalcite (without chloride ion intercalation) is used as a substrate to load the anionic conductive material of the present invention.

[0230] Comparative Example 4

[0231] (1) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot pressing. The hot pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0232] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0233] (2) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 752g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.3MPa for 6h. After washing and drying, obtain chloride ion modified nickel-iron hydrotalcite.

[0234] (3) Take 28g of resorcinol, 14L of formaldehyde, 10.5L of ethylenediamine and 2.8L of ethanol aqueous solution (the volume ratio of water to ethanol is 7:3), stir at 25℃ and 900r / min for 24h, and then calcine at 700℃ for 10h under an ammonia atmosphere so that more than 98wt% of the total amount is converted into elemental carbon, and obtain a nitrogen-modified carbon layer structure.

[0235] (4) 2.1g of chloride-modified nickel-iron hydrotalcite obtained in step (2) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water in a volume ratio of 3:1) to make a slurry. The slurry was coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to obtain chloride-modified nickel-iron hydrotalcite. The total nickel-iron content in the chloride-modified nickel-iron hydrotalcite was 80wt%.

[0236] (5) Add 1g of the carbon layer catalyst obtained in step (3) and 20g of 5% Nafion solution to 59g of isopropanol aqueous solution (obtained by mixing isopropanol and water in a volume ratio of 3:1) to make a slurry, coat it onto the cathode catalyst layer, and hot press it at 300℃ and 20MPa for 8min to form a composite chloride ion selective barrier material on the surface of the cathode catalyst layer.

[0237] The anionic conductive material is a nitrogen-modified carbon material, and based on a total weight of 100 wt% for the anionic conductive material, the mass content of the doping element is 2 wt%, and the mass content of carbon (including elemental carbon) is 98 wt%; the weight ratio of the anionic modified material to the anionic conductive material is 30:1; the average thickness of the anionic conductive material is 50 nm, the ionic conductivity is 0.7 S / cm, and the loading of the chloride ion selective blocking material is 5 mg / cm. 2 The cathode thickness is 80 micrometers; the Q0 / Q1 and I0 / I1 of the chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst are 0.992 and 0.992 respectively.

[0238] (6) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst with 83g of 5% Nafion solution and 59g of isopropanol. The anode slurry was coated onto the other side of the exchange membrane a material and subjected to hot pressing. The hot pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0239] (7) The electrolysis device obtained in (6) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0240] The electrolysis device and electrolysis method are the same as in Example 1, except that the anionic conductive material is not loaded on the anionic modified material, but the anionic conductive material and the anionic modified material are independently layered and stacked on each other in a zero-gap manner to form a whole.

[0241] Comparative Example 5

[0242] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 752g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.3MPa for 6h. After washing and drying, chloride ion modified nickel-iron hydrotalcite is obtained. Place it in 28g of resorcinol, 14L of formaldehyde, 10.5L of ethylenediamine and 2.8L of ethanol aqueous solution (the volume ratio of water to ethanol is 7:3) and stir at 25℃ and 950r / min for 24h to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst;

[0243] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 / g, with an average pore size of 5.2nm and an interlayer spacing d(003) of 0.8nm; chloride ion modified nickel-iron hydrotalcite, and based on the total weight of the anionic conductive material as 100wt%, the mass content of the doped element is 1.6wt%, and the mass content of carbon element (including the elemental carbon) is 98.4wt%; wherein the weight ratio of the anionic modified material to the anionic conductive material is 800:1; the average thickness of the anionic conductive material is 10nm, and the ionic conductivity is 0.08S / cm.

[0244] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0245] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0246] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0247] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0248] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0249] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0250] The electrolysis apparatus and electrolysis method are the same as in Example 1, except that: no roasting is performed in step (1).

[0251] Comparative Example 6

[0252] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 752g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.3MPa for 6h. After washing and drying, chloride ion modified nickel-iron hydrotalcite is obtained. It is placed in 28g of resorcinol, 14L of formaldehyde, 10.5L of ethylenediamine and 2.8L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stirred at 25℃ and 650r / min for 24h. Then, it is calcined at 400℃ for 3h under nitrogen atmosphere so that about 50wt% of the total amount is converted into elemental carbon to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0253] The chloride ion selective blocking material contains 80 wt% nickel and 4.0 wt% iron, with a molar ratio of 5:1 between nickel and iron. It has a layered structure with an average lateral dimension of 650 nm, an average longitudinal dimension of 22 nm, and a specific surface area of ​​140 m². 2 / g, pore volume 0.42cm 3 / g, with an average pore size of 5.2nm and an interlayer spacing d(003) of 0.8nm; chloride ion modified nickel-iron hydrotalcite, and based on the total weight of the anionic conductive material as 100wt%, the mass content of the doped element is 1.4wt%, and the mass content of carbon element (including the elemental carbon) is 98.6wt%; the weight ratio of the anionic modified material to the anionic conductive material is 400:1; the average thickness of the anionic conductive material is 15nm, and the ionic conductivity is 0.5S / cm.

[0254] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.996 and an I0 / I1 ratio of 0.996.

[0255] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0256] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0257] (3) 3.1g of the core-shell catalyst obtained in step (1) and 38g of 5% Nafion solution were added to 88g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) to form a slurry. This slurry was then coated onto the cathode catalyst layer and hot-pressed at 200℃ and 15MPa for 1min to form a chloride ion selective barrier material on the surface of the cathode catalyst layer. The loading of the chloride ion selective barrier material was 5mg / cm³. 2 The cathode thickness is 80 micrometers;

[0258] (4) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst, 83g of 5% Nafion solution, and 59g of isopropanol. The anode slurry was then coated onto the other side of the exchange membrane a material and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0259] (5) The electrolysis device obtained in (4) was tested by passing seawater through it. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0260] The electrolysis device and electrolysis method are the same as in Example 1, except that 50 wt% of the carbon precursor in step (1) is converted into elemental carbon.

[0261] Comparative Example 7

[0262] (1) Take 694g of nickel nitrate, 174g of ferric nitrate, 1.74kg of urea and 752g of sodium chloride and put them into a 70L reactor and stir evenly. React at 150℃, pH 9.5 and pressure 1.3MPa for 6h. After washing and drying, chloride ion modified nickel-iron hydrotalcite is obtained. It is placed in 28g of resorcinol, 14L of formaldehyde, 10.5L of ethylenediamine and 2.8L of ethanol aqueous solution (the volume ratio of water and ethanol is 7:3) and stirred at 25℃ and 750r / min for 24h. Then, it is calcined at 600℃ for 10h under an ammonia atmosphere so that more than 98wt% of the total amount is converted into elemental carbon to obtain chloride ion intercalated hydrotalcite@nitrogen modified carbon core-shell catalyst.

[0263] The chloride-modified nickel-iron hydrotalcite, based on 100 wt% of the total weight of the anionic conductive material, has a dopant element content of 1.4 wt% and a carbon element (including elemental carbon) content of 98.6 wt%. The weight ratio of the anionic modified material to the anionic conductive material is 118:1. The anionic conductive material has an average thickness of 6 nm and an ionic conductivity of 0.88 S / cm.

[0264] The chloride ion intercalated layered double hydroxide@nitrogen modified carbon core-shell catalyst has a Q0 / Q1 ratio of 0.998 and an I0 / I1 ratio of 0.998.

[0265] (2) 4.4 g of nickel alloy-based cathode catalyst (nickel-molybdenum atomic ratio of 6:1) and 26 g of 5% Nafion solution were added to 104 g of isopropanol aqueous solution (obtained by mixing isopropanol and water at a volume ratio of 3:1) and ultrasonically mixed to prepare a cathode slurry. This slurry was then coated onto one side of a 25*25 cm exchange membrane and subjected to hot-pressing. The hot-pressing conditions included a temperature of 120℃, a pressure of 5 MPa, and a time of 15 min to form a cathode catalyst layer on one side of the exchange membrane. The cathode catalyst loading in the cathode catalyst layer was 7 mg / cm³. 2 The cathode thickness is 80 micrometers;

[0266] The exchange membrane is an anion exchange membrane that allows water and anions to pass through. Its functional group is a dimethylpiperidine ion functional group, and its model is Versogen A80. The thickness of the exchange membrane is 80 micrometers.

[0267] (3) An anode slurry was prepared by mixing 5.3g of nickel-iron-based anode catalyst with 83g of 5% Nafion solution and 59g of isopropanol. The anode slurry was coated onto the other side of the exchange membrane a material and subjected to hot pressing. The hot pressing conditions included a temperature of 120°C, a pressure of 6MPa, and a time of 20min to form an anode catalyst layer. The loading of the anode catalyst in the anode catalyst layer was 8.5mg / cm³. 2 Ultimately, the final product is obtained.

[0268] (4) Chloride-intercalated hydrotalcite@nitrogen-modified carbon core-shell catalyst was placed in a seawater pretreatment tank as a packing material and connected to an electrolysis device. Seawater was introduced for testing. The operating temperature was 70℃, the operating pressure was 1.6MPaG, and the operating chamber voltage was 2.0V. The performance evaluation results are shown in Table 1.

[0269] The electrolysis device and electrolysis method are the same as in Example 1, except that: the anion-selective barrier material is loaded into the seawater pretreatment tank and then put into contact with other electrodes, that is, it is not a zero-gap method.

[0270] Test method: The membrane electrode was assembled in the electrolytic cell in the following order: end plate, sealing ring, cathode plate, membrane electrode, anode plate, sealing ring, and end plate. The electrolyte was 25% by weight alkaline seawater, with alkalinity derived from sodium hydroxide. Constant voltage test was performed, and the change in current was observed. The content of hypochlorite ions in the liquid was recorded and analyzed in real time. Impurity ions in the solution were analyzed using a UV-Vis spectrophotometer with a sampling interval of 4 hours and a full wavelength scanning method. The cell voltage was tested using the self-assembled electrolytic cell described above. The cell voltage was tested at 2V, and the current was tested after 5 hours and 500 hours of operation.

[0271] Table 1

Claims

1. A core-shell structured catalytic material, comprising an anion-modified material as a substrate and an anion-conductive material supported on the anion-modified material.

2. The core-shell structured catalytic material of claim 1, wherein the anion-modified material is selected from at least one of anion-intercalated materials, sulfides, phosphides, and nitrides, particularly anion-intercalated layered metal hydroxides, anion-intercalated layered bimetallic hydroxides (LDHs), or chloride-intercalated LDHs, preferably chloride-intercalated hydrotalcite materials, and particularly preferably chloride-intercalated nickel-iron-based hydrotalcites.

3. The core-shell structured catalytic material of claim 1, wherein the anionic modified material comprises at least one (preferably at least two) metallic elements selected from nickel, iron, cobalt, manganese, aluminum, copper, zinc, chromium, zirconium, and magnesium, preferably at least two metallic elements selected from nickel, iron, cobalt, manganese, chromium, and aluminum, and / or, based on 100 wt% of the total weight of the anionic modified material, the total content of the metallic elements is 55-90 wt% (preferably 65-85 wt%), and the content of the anions is 2-5 wt% (preferably 3.5-4.8 wt%).

4. The core-shell structured catalytic material of claim 1, wherein the average lateral dimension is 500-2000 nm (preferably 600-800 nm), the average longitudinal dimension is 1-100 nm (preferably 20-60 nm), and the specific surface area is 120-300 m². 2 / g, pore volume 0.35-0.55cm³ 3 / g, with an average pore size of 2-30nm.

5. The core-shell structured catalytic material according to claim 1, wherein the anionic conductive material is partially or completely coated on the anionic modified material, preferably completely coated on the anionic modified material.

6. The core-shell structured catalytic material of claim 1, wherein the anionic conductive material comprises elemental carbon and optionally at least one dopant element selected from nitrogen, fluorine, sulfur, boron, and phosphorus (preferably nitrogen), and the mass content of the dopant element is 0.05-8 wt% (preferably 0.1-5 wt%) based on 100 wt% of the total weight of the anionic conductive material, and the mass content of carbon (including the elemental carbon) is 92-99.95 wt% (preferably 98-99 wt%).

7. The core-shell structured catalytic material of claim 6, wherein the elemental carbon is derived from the carbonization of organic matter.

8. The core-shell structured catalytic material according to claim 1, wherein the weight ratio of the anion-modified material to the anion-conductive material is 10-2000 (preferably 30-1500).

9. The core-shell structured catalytic material according to claim 1, wherein the average thickness of the anion-conducting material is 0.5-50 nm (preferably 1-20 nm), and the ionic conductivity is 0.01-10 S / cm (preferably 0.05-1 S / cm).

10. The core-shell structured catalytic material according to claim 1, wherein Q0 / Q1 is 0.98-1.0 (preferably 0.99-1.0) and I0 / I1 is 0.98-1.0 (preferably 0.99-1.0).

11. The core-shell structured catalytic material of claim 1, wherein the average chemical composition of the anion intercalation material is expressed by the structural formula [A]. 1-x B x (OH)2]Y n- x / n The expression ·mH2O is schematic, wherein A is at least one metallic element selected from nickel, cobalt, manganese, copper, zinc, zirconium, and magnesium, preferably nickel, cobalt, manganese, and copper; B is at least one metallic element selected from iron, chromium, and aluminum, preferably at least one metallic element selected from iron and aluminum, provided that A and B are metals with different valence states; x is any value from 0.1 to 0.65 (preferably 0.15 to 0.37); Y represents an interlayer anion (e.g., at least one selected from chloride ion, carbonate ion, sulfate ion, nitrate ion, and phosphate ion, preferably chloride ion); n is an integer of 1, 2, or 3 (preferably 1); and m is 0.2 to 6 (preferably 0.3 to 1).

12. The core-shell structured catalytic material according to claim 1, wherein the anion-modified material has an average lateral dimension of 500-2000 nm (preferably 600-800 nm), an average longitudinal dimension of 1-800 nm (preferably 20-800 nm), and an interlayer spacing d(003) of 0.75-0.9 nm.

13. A method for manufacturing a core-shell structured catalytic material, comprising the following steps: The provision of anion intercalation materials is referred to as the provision step. The process of contacting the carbon precursor and, optionally, the dopant precursor with the anion intercalation material is called the loading step, which yields the composite precursor. The composite precursor is calcined to convert the carbon precursor into essentially all (e.g., more than 98 wt% of the total) elemental carbon. This is called the calcination step, and the core-shell structured catalytic material is obtained.

14. The manufacturing method of claim 13, wherein in the providing step, at least two metal salts are subjected to an intercalation reaction with an anionic intercalating agent to obtain the anionic intercalated material.

15. The manufacturing method of claim 14, wherein the operating conditions of the intercalation reaction include: The pH of the reaction system is 9-13, the reaction temperature is 110-200℃, the reaction time is 5-20h, and the reaction pressure is 0.8-2MPaG.

16. The manufacturing method of claim 14, wherein the weight ratio of the at least two metal salts to the anionic intercalating agent is 1:0.4-4 (preferably 1:0.8-2.5), and when at least two of the metal salts are included, the weight ratio between the different metal salts is 0.23-31 (preferably 0.7-3.5).

17. The manufacturing method of claim 14, wherein the metal salt is selected from at least two of iron, cobalt, nickel, manganese, copper, zinc, zirconium, magnesium, chromium, and aluminum, preferably from at least two of iron, cobalt, nickel, and manganese; the salt of the metal salt is selected from at least one of sulfate, chloride, nitrate, and complex ionic salt; and the anionic intercalating agent is selected from at least one of sodium chloride, cobalt chloride, ferric chloride, potassium chloride, nickel chloride, cobalt chloride, manganese chloride, and ammonium chloride, preferably from at least one of sodium chloride, cobalt chloride, ferric chloride, and potassium chloride.

18. The manufacturing method of claim 13, wherein in the loading step, the carbon precursor is selected from at least one of monosaccharides, polysaccharides, thermoplastic resins and thermosetting resins, preferably selected from at least one of glucose, sucrose, phenolic resins, benzoxazine resins and polyaniline, and the dopant precursor is selected from at least one of water-soluble or alcohol-soluble compounds containing the dopant element.

19. The manufacturing method of claim 13, wherein in the loading step, the weight ratio of the doped element precursor to the carbon element precursor is 0.05-3 (preferably 0.5-2.2), and the weight ratio of the carbon element precursor to the anion intercalation material is 0.05-8 (preferably 0.5-6).

20. The manufacturing method of claim 13, wherein the operating conditions of the loading step include: The reaction time is 0.1-25 h, the reaction temperature is 0-90 ℃, and the stirring speed is 200-1000 r / min.

21. The manufacturing method of claim 13, wherein the operating conditions of the calcination step include: Under a non-oxidizing gas atmosphere, the calcination temperature is 300-800℃ and the calcination time is 2-10h.

22. A layered electrode, comprising a cathode, an anion exchange membrane, and an anode in sequence, wherein an anion-selective blocking material layer is disposed at least at one location: outside the cathode, between the cathode and the anion exchange membrane, and between the anode and the anion exchange membrane, and the anion-selective blocking material is a core-shell structured catalytic material as described in any one of claims 1-12 or a core-shell structured catalytic material manufactured according to the manufacturing method described in any one of claims 13-21.

23. The layered electrode of claim 22, wherein the cathode, the anion exchange membrane, the anode and the anion selective barrier material layer are independently layered and stacked on top of each other in a zero-gap manner to form a whole.

24. A method for electrolyzing chloride-containing water (preferably seawater), comprising the step of electrolyzing the chloride-containing water using the layered electrode as described in any one of claims 22-23.

25. An electrolysis apparatus for chloride-containing water, comprising an electrolytic cell for containing chloride-containing water and a layered electrode as described in any one of claims 22-23.

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