Hydrogen production system based on metal-ammonia complex decoupling, hydrogen energy application system and method

Abstract

The present application relates to a kind of electrolytic water hydrogen production system based on metal-ammonia complex decoupling, hydrogen energy application system and method, specifically by electrolytic reaction, metal ions are deposited on the surface of carbon-based electrode for electrochemical energy storage to carry out electrochemical energy storage;For the carbon-based electrode loaded with metal after energy storage is completed and its corresponding electrolyte, hydrogen evolution is driven using metal-ammonia complex mode;After hydrogen evolution reaction is completed, the obtained metal-ammonia complex liquid is subjected to heat regeneration treatment, and the regenerated ammonia and metal ions are recycled in a closed loop;The electrolytic water hydrogen production system of the present application is driven by metal-ammonia complex decoupling and hydrogen evolution, which greatly improves the reaction rate, reduces the energy consumption and cost of hydrogen production, and uses metal-ammonia regeneration unit to regenerate metal ions and ammonia in a closed loop, to ensure long-term cycle stability, effectively solve the problems of high energy consumption and / or cost of existing electrolytic water hydrogen production technology, complex process, slow response, limited scene and intermittent renewable energy adaptation, etc.

Description

Technical Field

[0001] This disclosure relates to the field of decoupled water electrolysis hydrogen production technology, specifically to a water electrolysis hydrogen production system, hydrogen energy application system and method based on metal-ammonia complex decoupling. Background Technology

[0002] Electrolysis of water to produce hydrogen is a core direction for green hydrogen production due to its pure products and zero carbon emissions. Currently, the three main technologies are: alkaline water electrolysis, proton exchange membrane (PEM) water electrolysis, and solid oxide electrolysis. However, all of these technologies have limitations: traditional alkaline water electrolysis involves reaction coupling and high energy consumption; PEM water electrolysis involves reaction coupling and high cost; and both technologies suffer from non-recyclable raw materials and poor compatibility, limiting large-scale application. Solid oxide electrolysis technology faces challenges related to material lifespan and sealing, resulting in high system complexity and cost. For example, CN121700462A discloses a cold start control method for alkaline water electrolysis for hydrogen production, and CN121826743A discloses a magnetic field-controlled active ion-enhanced alkaline water electrolysis device and method, both requiring additional hardware and software support, increasing system cost and complicating system control. The complexity of the process is high; both the proton exchange membrane electrolysis method for hydrogen production disclosed in CN121737739A and the high-efficiency integrated component for a PEM exchange membrane electrolysis system for hydrogen production disclosed in CN121381024A require ultrapure water, resulting in high water production costs and the risk of hydrogen-oxygen cross-permeation; both the high-temperature solid oxide electrolysis system for hydrogen production disclosed in CN120719309A that couples solar thermal power generation and thermochemical thermal storage and the solid oxide electrolysis hydrogen production device and system disclosed in CN120443202A cannot avoid the material degradation and lifespan issues of SOEC high-temperature stacks and have poor cycle stability.

[0003] In summary, current mainstream technologies for hydrogen production via water electrolysis and existing hydrogen production technologies all have various shortcomings. Therefore, there is an urgent need to develop a new technical solution that can optimize the process flow of hydrogen production via water electrolysis, reduce production costs and energy consumption, and improve the system's operational flexibility and cycle stability. Summary of the Invention

[0004] In view of this, this disclosure provides a novel water electrolysis hydrogen production system that solves the problems of high energy consumption and / or high cost, and complex processes in existing mainstream water electrolysis hydrogen production technologies.

[0005] To achieve the aforementioned objectives, in a first aspect, the water electrolysis hydrogen production method based on metal-ammonia complex decoupling disclosed herein includes: Metal ions are loaded and deposited on the surface of a carbon-based electrode for electrochemical energy storage through an electrolytic reaction. After energy storage is completed, the carbon-based electrode loaded with metal and its corresponding electrolyte are driven by a metal-ammonia complexation method to drive hydrogen evolution. After the hydrogen evolution reaction is completed, the resulting metal-ammonia complex solution is thermally regenerated, and the regenerated ammonia and metal ions are recycled in a closed loop for use in the hydrogen production process.

[0006] Preferably, the criterion for determining the completion of metal ion deposition is: the deposition efficiency of metal ions on the surface of the carbon-based electrode for electrochemical energy storage is ≥95%.

[0007] Preferably, the method for driving hydrogen evolution using a metal-ammonia complexation includes: NH3 is introduced into the cathode electrolyte. The NH3 comes into contact with the metal on the surface of the metal-plated carbon-based electrode and undergoes a coordination reaction to form a metal complex. This causes the metal to desorb from the electrode surface and be oxidized. The released electrons are transferred to the anode electrode through an external circuit. Hydrogen ions in the electrolyte on the anode electrode side are reduced to generate hydrogen gas.

[0008] Preferably, NH3 is introduced into the cathode electrolysis chamber at a constant flow rate, and the NH3 is uniformly dispersed in the cathode electrolyte by a distributor; or NH3 is introduced in a pulse manner, with an introduction rate of 0.1 to 10 L / min, and the rate is continuously adjustable.

[0009] Preferably, the method for thermally regenerating the obtained metal-ammonia complex solution includes: The metal-ammonia complex solution is subjected to pyrolysis treatment, with the heating temperature controlled at 50-80℃ and the heating time at 30-60 min, while nitrogen gas is continuously introduced at a constant flow rate of 50 mL / min for purging. Under these conditions, the copper-ammonia complex undergoes a decomposition reaction, and the ammonia gas released during decomposition is cooled and recovered. The liquid phase system after the pyrolysis reaction is completed is an electrolyte containing regenerated metal ions, which is then recycled.

[0010] Secondly, the metal-ammonia complex-decoupled water electrolysis hydrogen production system disclosed herein includes: Electrolysis water hydrogen production unit and metal-ammonia regeneration unit; The water electrolysis hydrogen production unit includes a cathode electrolysis chamber and an anolysis chamber separated by an anion exchange membrane. The cathode electrolysis chamber is filled with a soluble metal salt electrolyte and equipped with a carbon-based electrode for electrochemical energy storage. The anolysis chamber is filled with an anolyte and equipped with an oxygen evolution electrode for decoupling water electrolysis hydrogen production. The metal-ammonia complex solution generated after the electrolysis reaction in the water electrolysis hydrogen production unit is transported to the metal-ammonia regeneration unit. The metal-ammonia regeneration unit includes a thermal regeneration device and a circulation channel. The thermal regeneration device is used to heat the metal-ammonia complex solution to dissociate and regenerate it. The circulation channel is used for closed-loop recovery of the regenerated metal ions and NH3.

[0011] Preferably, the soluble metal salt electrolyte is selected from one of the following: metal sulfate electrolyte, metal sulfonate electrolyte, and metal acetate electrolyte; and / or, The carbon-based electrode for electrochemical energy storage is selected from one of the following: carbon felt electrode, graphite electrode, carbon-based composite material electrode, and foamed carbon electrode; and / or, The oxygen evolution electrode for decoupled water electrolysis to produce hydrogen is selected from one of the following: iridium-based and ruthenium-based noble metal electrodes, transition metal and alloy electrodes, transition metal compound electrodes, carbon-based composite electrodes, and platinum electrodes; and / or, The anolyte is selected from either sulfate electrolyte or nitrate electrolyte.

[0012] Preferably, the soluble metal salt electrolyte is a metal sulfate electrolyte; and / or, The graphite electrode is selected from graphite electrodes and graphite felt electrodes; the carbon-based composite material electrode is selected from carbon cloth electrodes, carbon nanotube modified electrodes, and graphene-based electrodes; and / or, The bifunctional catalyst electrode refers to an electrode made of the same electrode material that exhibits highly efficient catalytic activity for both the hydrogen evolution reaction and the oxygen evolution reaction; the material of the bifunctional catalyst electrode is selected from one or more of transition metal phosphides, transition metal sulfides, transition metal oxides, layered double hydroxides (LDHs), metal-organic framework (MOF) derived materials, and heteroatom-doped carbon materials; and / or, The anolyte is Na2SO4 (sodium sulfate) electrolyte.

[0013] Preferably, the temperature of the heat treatment is 50-80°C.

[0014] Thirdly, the hydrogen energy application system described in this disclosure includes the water electrolysis hydrogen production system based on metal-ammonia complex decoupling as described in any of the second aspects.

[0015] The present invention has the following technical effects: The electrolytic water hydrogen production system of this invention innovatively adopts a metal-ammonia complex decoupling pathway, eliminating the need for catalysts at both the anode and cathode. This achieves complete spatiotemporal separation of the HER (hydrogen evolution reaction) and OER (oxygen evolution reaction), eliminating the risk of gas mixing, simplifying the process, and reducing hydrogen production costs. Through spatiotemporal separation via electrodeposition and ammonia decoupling, it enables on-demand hydrogen production. Hydrogen production is precisely triggered / terminated by pulsed NH3 injection, with a continuously adjustable rate of 0.1–10 L / min, short response time, and adaptability to the intermittent nature of renewable energy sources. The system's energy consumption per unit of hydrogen production is only 5.02 kWh·m³. -3 The energy conversion efficiency remains stable at over 50% under voltages of 2.0–2.8V, offering superior cost and energy efficiency. The metal-ammonia complex can achieve closed-loop regeneration of the reaction medium through low-temperature thermal decomposition, ensuring long-term cycle stability. The system's cycle stability exceeds 5000 hours, significantly improving adaptability and reducing hydrogen production energy consumption and costs. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the specification, serve to illustrate the technical solutions of this disclosure.

[0017] Figure 1 is a schematic diagram of the ammonia decoupled electrolysis water production system based on thermal regeneration in Embodiment 1 of the present invention; Figure 2 shows the electrochemical energy storage stage in Example 1 of the present invention; Figure 3 illustrates the metal-ammonia complex-driven hydrogen evolution stage in Example 1 of the present invention. Figure 4 illustrates the heat-driven regeneration and metal recycling stages in Embodiment 1 of the present invention. In the diagram: 1-Anode electrolysis chamber, 2-Bifunctional catalyst electrode, 3-Anion exchange membrane, 4-Cathode electrolysis chamber, 5-Carbon felt electrode, 6-NH3 pump, 7-Metal ion pump, 8-Copper ammonia complex solution, 9-Thermal regeneration device. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] To address the technical problems mentioned in the background, the core technology of the water electrolysis hydrogen production method disclosed herein is: Electrochemical energy storage is achieved by loading and depositing metal ions on the surface of a carbon-based electrode for electrochemical energy storage through an electrolytic reaction. After energy storage is completed, hydrogen evolution is driven by a metal-ammonia complexation method on the metal-loaded carbon-based electrode and its corresponding electrolyte. After the hydrogen evolution reaction is completed, the resulting metal-ammonia complex solution is thermally regenerated, and the regenerated ammonia and metal ions are recycled in a closed loop for use in the hydrogen production process.

[0020] In a specific embodiment, the criterion for determining the completion of metal ion deposition is: the deposition efficiency of metal ions on the surface of the carbon-based electrode for electrochemical energy storage is ≥95%. When both conditions are met simultaneously, the metal ion deposition is considered complete, and the subsequent metal-ammonia complexation-driven hydrogen evolution step can proceed. Herein, a deposition efficiency of ≥95% means that at least 95% of the metal ions participating in the reaction are successfully loaded and deposited on the surface of the carbon-based electrode.

[0021] In a specific embodiment, the method of driving hydrogen evolution using a metal-ammonia complex is as follows: NH3 is introduced into the cathode electrolyte. The NH3 contacts the metal on the surface of the metal-plated carbon-based electrode and undergoes a coordination reaction to form a metal complex. This causes the metal to desorb from the electrode surface and be oxidized. The released electrons are transferred to the anode electrode through an external circuit, and the hydrogen ions in the electrolyte on the anode electrode side are reduced to generate hydrogen gas. Preferably, NH3 is introduced into the cathode electrolysis chamber at a constant flow rate, and the NH3 is uniformly dispersed in the cathode electrolyte by a distributor; or NH3 is introduced in a pulsed manner to precisely trigger / terminate hydrogen production, with an introduction rate of 0.1–10 L / min, and the rate is continuously adjustable.

[0022] In a specific embodiment, the method for thermally regenerating the obtained metal-ammonia complex and recycling the regenerated ammonia and metal ions in a closed loop for use in the hydrogen production process is as follows: the metal-ammonia complex is subjected to pyrolysis treatment, with the heating temperature controlled at 50-80°C and the heating time at 30-60 min, while high-purity nitrogen is continuously introduced at a constant flow rate of 50 mL / min for purging; under these conditions, the copper-ammonia complex undergoes a decomposition reaction, and the ammonia gas released from the decomposition is cooled and recovered; the liquid phase system after the pyrolysis reaction is completed is an electrolyte containing regenerated metal ions, and the electrolyte is recycled.

[0023] Based on the aforementioned core technologies, this disclosure presents the following design for a water electrolysis hydrogen production system, which includes: Electrolysis water hydrogen production unit and metal-ammonia regeneration unit; The water electrolysis hydrogen production unit includes a cathode electrolysis chamber and an anolysis chamber separated by an anion exchange membrane. The cathode electrolysis chamber is filled with a soluble metal salt electrolyte and equipped with a carbon-based electrode for electrochemical energy storage. The anolysis chamber is filled with an anolyte and equipped with an oxygen evolution electrode for decoupling water electrolysis hydrogen production. The metal-ammonia complex solution generated after the electrolysis reaction in the water electrolysis hydrogen production unit is transported to the metal-ammonia regeneration unit. The metal-ammonia regeneration unit includes a thermal regeneration device and a circulation channel. The thermal regeneration device is used to heat the metal-ammonia complex solution to dissociate and regenerate it. The circulation channel is used for closed-loop recovery of the regenerated metal ions and NH3.

[0024] In a specific embodiment, the soluble metal salt electrolyte is selected from one of the following: metal sulfate electrolyte, metal sulfonate electrolyte, and metal acetate electrolyte. Preferably, it is a metal sulfate electrolyte.

[0025] In a specific embodiment, the carbon-based electrode for electrochemical energy storage is selected from one of carbon felt electrode, graphite electrode, carbon-based composite material electrode, and foamed carbon electrode; preferably, the graphite electrode is selected from one of graphite electrode and graphite felt electrode; and the carbon-based composite material electrode is selected from one of carbon cloth electrode, carbon nanotube modified electrode, and graphene-based electrode.

[0026] In specific embodiments, the anodic oxygen evolution electrode is required to possess good conductivity and OER catalytic activity, as well as resistance to corrosion during the electrolysis process. It must be able to stably participate in the anodic oxygen evolution reaction to maintain the system's charge balance, while avoiding side reactions with ammonia and metal ions, ensuring compatibility with the metal ion electrodeposition energy storage, metal-ammonia complex hydrogen evolution, and low-temperature thermal regeneration closed-loop process of this invention. This includes iridium-based and ruthenium-based noble metal electrodes, transition metal and alloy electrodes, transition metal compound electrodes, carbon-based composite electrodes, and bifunctional catalyst electrodes; preferably, bifunctional catalyst electrodes, which refer to electrodes made of the same electrode material that exhibit highly efficient catalytic activity for both the hydrogen evolution reaction and the oxygen evolution reaction. The material of the bifunctional catalyst electrode is selected from one or more of transition metal phosphides, transition metal sulfides, transition metal oxides, layered bimetallic hydroxides (LDH), metal-organic framework (MOF) derived materials, and heteroatom-doped carbon materials.

[0027] In specific embodiments, the cathode electrolyte is required to not undergo side reactions with the cathode electrode and not affect the metal ion electrodeposition energy storage and subsequent metal-ammonia complexation hydrogen evolution and low-temperature thermal regeneration closed-loop process; it includes sulfate electrolyte, nitrate electrolyte and mixed electrolyte solution; preferably, Na2SO4 (sodium sulfate) electrolyte is used.

[0028] This disclosure also provides a hydrogen energy application system, which includes a water electrolysis hydrogen production system based on metal-ammonia complex decoupling.

[0029] The following are preferred embodiments of this disclosure.

[0030] like Figure 1 As shown, the water electrolysis hydrogen production system includes an anion exchange membrane dual-chamber water electrolysis hydrogen production unit and a metal-ammonia regeneration unit. The anion exchange membrane dual-chamber water electrolysis hydrogen production unit includes a dual-chamber electrolyzer, which is divided into an independent anode electrolysis chamber 1 and a cathode electrolysis chamber 4 by an anion exchange membrane 3. The two chambers are required to be sealed, with no leakage of electrolyte between the two sides, and only the directional migration of anions is allowed.

[0031] The anode electrolysis chamber 1 is equipped with a bifunctional catalyst electrode 2, which has a size of 100×100mm; the cathode electrolysis chamber 4 is equipped with a carbon felt electrode 5, which has a size of 100×100×5mm and has excellent load stability, making it suitable for metal ion deposition energy storage requirements.

[0032] Regarding electrolyte preparation and filling, sodium sulfate electrolyte is placed in anolyte chamber 1 as the cathode electrolyte; metal sulfate electrolyte is placed in catholyte chamber 4 as the catholy electrolyte. The prepared anolyte and catholyte are precisely injected into their respective chambers via pumps, with strict isolation throughout by anion exchange membrane 3 to prevent crosstalk between the electrolytes. This dual-chamber electrolytic cell is assembled from acrylic plates, nuts, and bolts; the acrylic plates have external dimensions of 80×80×20mm and a central 40×40mm chamber opening; the components are isolated using silicone gaskets and secured with M5 bolts (100mm in length) and their matching nuts.

[0033] The metal-ammonia regeneration unit includes a thermal regeneration device 9 connected to the cathode electrolysis chamber 4 via pipeline. The thermal regeneration device 9 is used to heat the complexed metal-ammonia system at a low temperature of 50-80°C to achieve closed-loop regeneration of metal ions and NH3. The regenerated metal ions and NH3 can be circulated to the cathode electrolysis chamber 4 through the NH3 pump 6 and the metal ion pump 7, respectively.

[0034] The working process of the water electrolysis hydrogen production system described in this embodiment is as follows: (1) Operational procedures for the electrochemical energy storage stage: Connect an external DC power supply and adjust the electrolysis voltage to 1.8–2.8 V, with a preferred operating voltage of 2.7 V. The system then officially enters energy storage mode and initiates the electrolysis reaction. Figure 2As shown, metal ions in the cathode electrolysis chamber 4 undergo a reduction reaction on the surface of the carbon felt electrode 5, achieving valence state transformation and stable loading and deposition on the electrode surface, thereby replacing the traditional cathode hydrogen evolution (HER) reaction path of water electrolysis and completing electrochemical energy storage; at the same time, the sodium sulfate electrolyte in the anode electrolysis chamber 1 undergoes a water oxidation oxygen evolution (OER) reaction on the surface of the bifunctional catalyst electrode 2, maintaining the charge balance of the system.

[0035] Energy storage process termination criteria: Once the metal ion deposition in the cathode electrolysis chamber 4 is completed and the deposition efficiency is ≥95%, the external power supply is turned off, and the entire electrochemical energy storage process is completed.

[0036] (2) Operational process for hydrogen evolution stage driven by metal-ammonia complexation: For the metallized carbon felt electrode and corresponding electrolyte that have completed energy storage, ammonia gas is introduced into the cathode electrolysis chamber 4 at a constant flow rate. The ammonia gas is uniformly dispersed in the electrolyte by a distributor, ensuring full contact with the metal on the surface of the metallized carbon felt electrode. The introduced ammonia gas undergoes a coordination reaction with the metal to form a metal complex, which promotes the desorption of the metal from the electrode surface and its oxidation. The released electrons are transferred to the bifunctional catalyst electrode 2 through an external circuit. Hydrogen ions in the electrolyte on the bifunctional catalyst electrode side are reduced to generate hydrogen gas (hydrogen evolution Faraday efficiency ≥92%, unit hydrogen production energy consumption is 5.02 kWh / m³). This process requires no additional power input and can achieve on-demand and controllable hydrogen release, possessing excellent on-demand production capabilities.

[0037] After the ammonia gas undergoes a coordination reaction with the metal, the copper-ammonia complex solution in the resulting reaction mixture is transported to a thermal regeneration system to complete the thermal decomposition and regeneration of the copper-ammonia complex, providing raw materials for subsequent cyclic reactions.

[0038] (3) The operation process for the thermal regeneration and circulation stage is as follows: like Figure 4 As shown, the copper-ammonia complex liquid 8 obtained after gas-liquid separation is pumped into the heating regeneration device 9. The heating temperature is controlled at 70-80℃ and the heating time is 30-60 min. At the same time, high-purity nitrogen gas is continuously purged at a constant flow rate of 50 mL / min. Under these conditions, the copper-ammonia complex undergoes a decomposition reaction with a decomposition efficiency ≥95%. The ammonia gas released during decomposition is cooled and recovered in a condenser. The recovered ammonia gas is then transported to an ammonia storage device for storage and directly returned to the anion exchange membrane dual-chamber water electrolysis hydrogen production unit via NH3 pump 6 to participate in the electrochemical energy storage stage reaction again, realizing the recycling of ammonia gas. The entire process is ammonia-free.

[0039] After the pyrolysis reaction is completed, the liquid phase system is an electrolyte containing regenerated metal ions. After cooling and adjusting the concentration to the set range, the electrolyte is directly returned to the anion exchange membrane dual-chamber water electrolysis hydrogen production unit through metal ion pump 7 to participate in the electrochemical energy storage stage reaction again, with a reuse rate of up to 100%.

[0040] Throughout the entire thermal regeneration and recycling process, the regenerated metal ions, electrolyte, and recovered ammonia are all recycled back, forming a complete closed loop with the electrochemical energy storage and hydrogen evolution stages mentioned above, ensuring the long-term stable operation of the system.

[0041] The main performance indicators of the water electrolysis hydrogen production system described in this embodiment are as follows: (1) Reduced energy consumption: Energy consumption per unit of hydrogen production is reduced to 5.02 kWh·m -3 It can operate stably at low voltage, which is significantly lower than that of traditional proton exchange membrane electrolysis of water.

[0042] (2) High reaction efficiency and good operational stability: Faraday efficiency is 92.87%, complexation reaction initiation potential is +0.19 V (vs. RHE), and reaction initiation and conversion efficiency are significantly improved; after multiple cycles, the electrode polarization performance is stable, hydrogen production start-up and shutdown are synchronized with ammonia supply, and the controllability is strong; the energy conversion efficiency is stable at over 50% in the range of 2.0–2.8 V.

[0043] (3) Raw material saving and simple process: For example, Cu 2+ It features closed-loop regeneration with NH3 (decomposition efficiency exceeding 94% at temperatures above 70℃), no copper loss, reduced waste emissions, recyclable and reusable ammonia, no need for additional acid dissolution steps, and a compact three-step cycle process.

[0044] In summary, compared with traditional water electrolysis systems, the water electrolysis hydrogen production system described in this patent has the following technical advantages: (1) Achieving synergistic optimization of low energy consumption and high selectivity, hydrogen can be produced at ambient temperature and pressure. Under the combined conditions of ambient pressure, ambient temperature electrolysis and low temperature regeneration, the system can achieve a hydrogen evolution Faraday efficiency of over 92%, with a unit hydrogen production energy consumption as low as 5.02 kWh·m³. -3 It achieves hydrogen production at room temperature and pressure, significantly lower than the traditional proton exchange membrane water electrolysis method; through voltage optimization, it achieves efficient metal deposition and highly selective hydrogen evolution, solving the problems of slow kinetics and product mixing in traditional water electrolysis.

[0045] (2) By decoupling HER and OER driven by metal (copper, zinc, nickel, etc.)-ammonia complexation, proton storage and hydrogen release are separated in time and space, which greatly improves the reaction rate and achieves low energy consumption. Taking copper as an example, electrochemical measurements show that the onset potential of copper reduction reaction (+0.75 V vs. RHE) is significantly higher than that of hydrogen evolution reaction (0 V vs. RHE), thereby reducing the theoretical cell voltage.

[0046] (3) By storing protons in the electrolyte, the inherent capacity limitation of thermally regenerated catalysts is effectively avoided. Metal-ammonia complexes can achieve closed-loop regeneration of the reaction medium through low-temperature thermal decomposition, ensuring long-term cycle stability.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing hydrogen through water electrolysis based on metal-ammonia complex decoupling, characterized in that, include: Metal ions are loaded and deposited on the surface of a carbon-based electrode for electrochemical energy storage through an electrolytic reaction to achieve electrochemical energy storage. For the carbon-based electrode loaded with metal and its corresponding electrolyte after energy storage is completed, hydrogen evolution is driven by metal-ammonia complexation. After the hydrogen evolution reaction is completed, the resulting metal-ammonia complex solution is thermally regenerated, and the regenerated ammonia and metal ions are recycled in a closed loop for use in the hydrogen production process.

2. The method for producing hydrogen by water electrolysis according to claim 1, characterized in that: The criterion for determining the completion of metal ion deposition is: the deposition efficiency of metal ions on the surface of carbon-based electrodes for electrochemical energy storage is ≥95%.

3. The method for producing hydrogen by water electrolysis according to claim 1 or 2, characterized in that, The method for driving hydrogen evolution using a metal-ammonia complexation includes: NH3 is introduced into the cathode electrolyte. The NH3 comes into contact with the metal on the surface of the metal-plated carbon-based electrode and undergoes a coordination reaction to form a metal complex. This causes the metal to desorb from the electrode surface and be oxidized. The released electrons are transferred to the anode electrode through an external circuit. Hydrogen ions in the electrolyte on the anode electrode side are reduced to generate hydrogen gas.

4. The method for producing hydrogen by water electrolysis according to claim 3, characterized in that: NH3 is introduced into the cathode electrolysis chamber at a constant flow rate, and the NH3 is evenly dispersed in the cathode electrolyte by a distributor; Alternatively, NH3 can be introduced in a pulse manner at a rate of 0.1–10 L / min, which is continuously adjustable.

5. The method for producing hydrogen by water electrolysis according to claim 1, characterized in that, The method for thermal regeneration of the obtained metal-ammonia complex solution includes: The metal-ammonia complex solution is subjected to pyrolysis treatment, with the heating temperature controlled at 50-80℃ and the heating time at 30-60 min, while nitrogen gas is continuously introduced at a constant flow rate of 50 mL / min for purging. Under these conditions, the copper-ammonia complex undergoes a decomposition reaction, and the ammonia gas released during decomposition is cooled and recovered. The liquid phase system after the pyrolysis reaction is completed is an electrolyte containing regenerated metal ions, which is then recycled.

6. A hydrogen production system for water electrolysis based on metal-ammonia complex decoupling, characterized in that, include: Electrolysis water hydrogen production unit and metal-ammonia regeneration unit; The water electrolysis hydrogen production unit includes a cathode electrolysis chamber and an anolysis chamber separated by an anion exchange membrane. The cathode electrolysis chamber is filled with a soluble metal salt electrolyte and equipped with a carbon-based electrode for electrochemical energy storage. The anolysis chamber is filled with an anolyte and equipped with an oxygen evolution electrode for decoupling water electrolysis hydrogen production. The metal-ammonia complex solution generated after the electrolysis reaction in the water electrolysis hydrogen production unit is transported to the metal-ammonia regeneration unit. The metal-ammonia regeneration unit includes a thermal regeneration device and a circulation channel. The thermal regeneration device is used to heat the metal-ammonia complex solution to dissociate and regenerate it. The circulation channel is used for closed-loop recovery of the regenerated metal ions and NH3.

7. The water electrolysis hydrogen production system according to claim 6, characterized in that: The soluble metal salt electrolyte is selected from one of the following: metal sulfate electrolyte, metal sulfonate electrolyte, and metal acetate electrolyte; and / or, The carbon-based electrode for electrochemical energy storage is selected from one of the following: carbon felt electrode, graphite electrode, carbon-based composite material electrode, and foamed carbon electrode; and / or, The oxygen evolution electrode is selected from one of the following: iridium-based and ruthenium-based noble metal electrodes, transition metal and alloy electrodes, transition metal compound electrodes, carbon-based composite electrodes, and bifunctional catalyst electrodes; and / or, The anolyte is selected from either sulfate electrolyte or nitrate electrolyte.

8. The water electrolysis hydrogen production system according to claim 7, characterized in that: The soluble metal salt electrolyte is a metal sulfate electrolyte; and / or, The graphite electrode is selected from graphite electrodes and graphite felt electrodes; the carbon-based composite material electrode is selected from carbon cloth electrodes, carbon nanotube modified electrodes, and graphene-based electrodes; and / or, The bifunctional catalyst electrode refers to an electrode made of the same electrode material that exhibits highly efficient catalytic activity for both the hydrogen evolution reaction and the oxygen evolution reaction; the material of the bifunctional catalyst electrode is selected from one or more of transition metal phosphides, transition metal sulfides, transition metal oxides, layered bimetallic hydroxides, metal-organic framework-derived materials, and heteroatom-doped carbon materials; and / or, The anolyte is Na2SO4 electrolyte.

9. The water electrolysis hydrogen production system according to any one of claims 6-8, characterized in that: The temperature for the heat treatment is 50-80℃.

10. A hydrogen energy application system, characterized in that, include: The water electrolysis hydrogen production system based on metal-ammonia complex decoupling as described in any one of claims 6-9.

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