System and method for electrochemical direct synthesis of gaseous deuterated ammonia

Abstract

This invention discloses a system and method for the direct electrochemical synthesis of gaseous deuterated ammonia, belonging to the field of electrochemical synthesis technology. The system comprises a nitrogen source activation device, a nitrogen source purification and adjustment device, a gaseous ammonia reaction device, a gaseous ammonia extraction device, and a gaseous ammonia separation and purification device connected in sequence. The method specifically includes the following steps: (1) introducing a nitrogen source; (2) introducing a deuterium source; (3) electrochemical conversion reaction; (4) extraction, separation, and purification to obtain high-purity gaseous deuterated ammonia. This invention avoids the dissolution and secondary desorption process of deuterated ammonia in the electrolyte, reduces deuterium source loss and separation energy consumption, improves deuterium utilization efficiency and product purity, and achieves a deuterated ammonia preparation efficiency close to the single-pass conversion level of the solid-phase nitride hydrolysis route while reducing energy consumption and carbon emissions. It is also suitable for the continuous electrochemical preparation of high-purity gaseous deuterated ammonia and high-purity gaseous conventional ammonia.

Description

Technical Field

[0001] This invention relates to the field of electrochemical synthesis technology, and more specifically to a system and method for the direct electrochemical synthesis of gaseous deuterated ammonia. Background Technology

[0002] Ammonia-d3, also known as deuterated ammonia or trideuterated ammonia, with the chemical formula D3N, is an isotope-labeled compound formed by replacing three hydrogen atoms in ammonia gas with deuterium. As an important isotopic chemical, deuterated ammonia has wide applications in semiconductor manufacturing, isotope labeling, fine chemicals, and nuclear technology. With the development of high-end manufacturing and isotope technology, the demand for high-isotope abundance and high-purity deuterated ammonia is constantly increasing. Therefore, how to achieve efficient and low-loss preparation of deuterated ammonia has become an urgent technical problem to be solved.

[0003] Currently, the main methods for preparing deuterated ammonia include solid-phase nitride hydrolysis, heterogeneous thermocatalytic synthesis, and liquid isotope exchange. Among these, solid-phase nitride hydrolysis generates deuterated ammonia through a stoichiometric reaction of solid nitrogen compounds with heavy water. While it boasts strong reaction driving force and high isotope inheritance, this method suffers from low atom economy and generates a large amount of solid-phase byproducts, leading to deuterium resource retention and complex solid waste treatment, making it difficult to meet the demands of continuous and large-scale production. Heterogeneous thermocatalytic synthesis is typically carried out under high temperature and high pressure conditions. Limited by thermodynamic equilibrium, its single-pass conversion rate is low, requiring a high recycling rate to improve overall conversion efficiency. During the recycling process, venting is usually necessary to maintain system stability and material balance, resulting in the loss of deuterium source with unreacted gases, thus increasing raw material consumption and operating costs, and limiting the process's economics and flexibility. Liquid isotope exchange is based on the isotope fractionation equilibrium between ammonia molecules and heavy water. It achieves hydrogen isotope replacement through multi-stage cascade exchange. Although it can post-process and label existing ammonia products, its kinetic process is slow and the separation and dehydration process is complex, making it difficult to achieve high-throughput, low-energy continuous production while ensuring high isotope abundance.

[0004] In recent years, electrochemical synthesis technology has attracted widespread attention due to its advantages such as mild reaction conditions and high process tunability. However, existing research on electrochemical deuterated ammonia mainly uses liquid-phase electrolyte systems. Deuterated ammonia is easily soluble in the electrolyte after generation, usually requiring secondary analysis and separation processes. This not only increases system energy consumption and process complexity, but also easily leads to problems such as deuterium source cross-contamination and product cross-interface migration, thus limiting further improvements in deuterium utilization efficiency and product purity.

[0005] Therefore, how to develop an electrochemical preparation process that can avoid liquid-phase dissolution and achieve direct gas-phase generation and output of deuterated ammonia is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a system and method for the direct electrochemical synthesis of gaseous deuterated ammonia, in order to solve the problems of high energy consumption, complex process, large deuterium source loss and difficulty in achieving direct gaseous output of products in the prior art. In particular, in the existing liquid-phase electrochemical system, deuterated ammonia is easily soluble in electrolyte and requires secondary analysis and separation, which leads to limitations in deuterium utilization efficiency and product purity.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A system for the direct electrochemical synthesis of gaseous deuterated ammonia includes a nitrogen source activation device, a nitrogen source purification and regulation device, a gaseous ammonia reaction device, a gaseous ammonia extraction device, and a gaseous ammonia separation and purification device connected in sequence.

[0009] The system of this invention can realize deuterium source activation, deuterium nucleus transfer across regions, electrochemical conversion of nitrogen-containing species, and direct extraction of gaseous deuterated ammonia under the action of an external electric field, and can be integrated with downstream separation, purification and control units.

[0010] Furthermore, the aforementioned nitrogen source activation device is used to activate the nitrogen source using plasma, and is used in conjunction with the nitrogen source purification and conditioning device to obtain a nitrogen source suitable for electrochemical reactions.

[0011] Furthermore, the structure of the aforementioned gas-phase ammonia reactor is a flat plate type.

[0012] Furthermore, the aforementioned gas-phase ammonia reaction device includes an electrochemical reaction unit for completing a one-step electrochemical conversion of nitrogen-containing species into deuterated ammonia.

[0013] Furthermore, the aforementioned electrochemical reaction unit includes a cathode flow channel, a cathode catalyst layer, a conductive and insulating structure, an anode catalyst layer, and an anode flow channel stacked sequentially, and the voltage and current required for the electrochemical reaction are applied by an external power source.

[0014] The further beneficial effect of the above-mentioned method lies in that the electrochemical reaction unit of the present invention includes mutually separated anode reaction zones (anode flow channel, anode catalyst layer) and cathode reaction zones (cathode flow channel, cathode catalyst layer). These two zones are spatially independent but electrochemically connected under the influence of an electric field. The cathode reaction zone is used to introduce nitrogen-containing reactants and generate gaseous deuterated ammonia under liquid-phase electrolyte conditions. The anode reaction zone is used to introduce heavy water or deuterium gas as a deuterium source and generate migratory deuterium nuclei under an applied electric field. A conductive and insulating structure is provided between the two zones to enable the directional migration of deuterium nuclei from the anode reaction zone to the cathode reaction zone under the influence of the electric field and to suppress non-selective mixing of substances. The cathode reaction zone includes a cathode catalyst layer and / or a gas diffusion layer. The cathode catalyst layer contains catalytic materials capable of adsorbing nitrogen-containing reactants and promoting their electrochemical conversion. An interfacial functional layer can be provided to synergistically regulate the deuterium nucleus transport resistance and the adsorption coverage of nitrogen-containing reactants, thereby improving the selectivity of gaseous deuterated ammonia generation.

[0015] Furthermore, the aforementioned conduction and isolation structure is a proton conduction membrane. There are no limitations on the material composition, conduction mechanism, or structural morphology of the conduction and isolation structure, as long as it can achieve the directional transport of deuterium nuclei under the influence of an applied electric field.

[0016] The further beneficial effect of adopting the above is that a conduction and isolation structure with deuterium nucleus transfer capability is set between the anode reaction region and the cathode reaction region, which is used to realize the migration of deuterium nuclei or their equivalent transfer forms between different reaction regions, while suppressing non-selective mixing of gases, liquids or solutes.

[0017] Furthermore, the aforementioned gaseous ammonia extraction device includes a gas collection chamber, an extraction pipeline, a pressure regulating device, or a combination thereof, for extracting the generated gaseous deuterated ammonia from the reaction zone to ensure stable output of the gaseous product.

[0018] Furthermore, the aforementioned gas phase ammonia separation and purification device includes, but is not limited to: a condensation device, an adsorption or desorption device, a membrane separation device, a distillation device, or any combination thereof, used to further process the derived gas phase product to obtain a deuterated ammonia product of the target purity.

[0019] Furthermore, the aforementioned system for the direct electrochemical synthesis of gaseous deuterated ammonia also includes a heavy water electrolysis device and / or a deuterium supply device connected to the gaseous ammonia reaction apparatus, for providing a deuterium source to the anode reaction zone.

[0020] The further beneficial effect of the above-mentioned method is that the heavy water electrolysis device and / or deuterium gas supply device are used to electrolyze heavy water to generate deuterium gas and / or generate a deuterium-containing medium for the anode reaction, thereby providing a deuterium source to the anode reaction zone.

[0021] Furthermore, the aforementioned system for the direct electrochemical synthesis of gaseous deuterated ammonia also includes a deuterium source recycling device connected in a loop to the gaseous ammonia reactor. This device is used to recover unreacted nitrogen-containing reactants and / or deuterium sources and return them to the cathode reaction zone and / or anode reaction zone for reuse. The recovered substances include, but are not limited to, unreacted deuterium gas, unconsumed heavy water, and deuterium-containing gas / vapor mixtures. The recovered deuterium source can be returned to the anode reaction zone and / or to the heavy water electrolysis unit and / or deuterium supply unit for cyclic supply. The deuterium source recycling device can be installed independently or integrated, and its connection method, recovery path, and reflux ratio are unrestricted.

[0022] The further beneficial effect of adopting the above is that, depending on the form of the deuterium source (heavy water and / or deuterium gas) feed, the unreacted deuterium source can be recycled back to the anode reaction zone in the form of deuterium gas, or the unconsumed heavy water can be recycled back to the anode reaction zone or the deuterium source supply device.

[0023] Furthermore, the aforementioned system for the direct electrochemical synthesis of gaseous deuterated ammonia also includes reactant supply and distribution devices connected to the anode and cathode reaction zones, respectively, including but not limited to: gas supply pipelines, distribution manifolds, and mass flow control devices; liquid supply pipelines, metering pumps, and storage containers; and gas-liquid mixing or switching devices. The deuterium source can be introduced in the form of heavy water, deuterium gas, or a combination thereof; the nitrogen-containing reactants can be introduced in the gas phase, vapor phase, or a combination thereof, and the specific supply method is unrestricted. This system is used to achieve zoned supply of the deuterium source and nitrogen-containing reactants.

[0024] Furthermore, the aforementioned system for the direct electrochemical synthesis of gaseous deuterated ammonia also includes operation control and auxiliary devices, including but not limited to: power supply and current / voltage control devices; temperature / pressure control devices; safety protection devices; and data acquisition and automation control devices, used to regulate and monitor voltage, current, temperature, pressure, and / or flow rate, thereby ensuring stable operation and condition adjustment of the system.

[0025] It should be noted that the above-mentioned devices of the present invention are all optional auxiliary devices / functional modules used to achieve stable operation of the above-mentioned core unit, improve operating efficiency, or facilitate engineering integration. The installation position, connection method, structural form and quantity of the above-mentioned devices are not limited and can be configured or omitted according to specific working conditions, production requirements and engineering scale-up requirements. Such changes should not be construed as limiting the scope of protection of the present invention.

[0026] An electrochemical method for the direct synthesis of gaseous deuterated ammonia, using the above-mentioned system, specifically includes the following steps: (1) First, the nitrogen source is activated by passing it into the nitrogen source activation device, then purified and regulated by the nitrogen source purification and regulation device, and finally passed into the gas phase ammonia reaction device; or, the pre-prepared nitrogen source is directly passed into the gas phase ammonia reaction device. (2) Introduce the deuterium source into the gas-phase ammonia reaction apparatus; (3) Under the drive of an electric field, the deuterium source and the nitrogen source undergo a one-step electrochemical conversion reaction to directly generate gaseous deuterated ammonia; (4) First, the gaseous deuterated ammonia is introduced into the gaseous ammonia export device for export, and then introduced into the gaseous ammonia separation and purification device for separation and purification to obtain high-purity gaseous deuterated ammonia.

[0027] The synthesis mechanism of high-purity gaseous deuterated ammonia in this invention is as follows: A deuterium source is introduced into the anode reaction zone, where migratory deuterium nuclei are generated under an applied electric field. Nitrogen-containing reactants are introduced into the cathode reaction zone, where no liquid electrolyte is used, allowing the nitrogen-containing reactants to participate in the reaction under gaseous or gas-solid interface conditions. Driven by the electric field, the deuterium nuclei migrate directionally from the anode to the cathode reaction zone through a conduction and isolation structure, and undergo a one-step electrochemical conversion reaction with the nitrogen-containing reactants at the cathode reaction interface, directly generating gaseous deuterated ammonia on the cathode side, which is then exported through a gaseous ammonia export device. The gaseous product export structure is connected to the gaseous separation and purification unit to obtain deuterated ammonia products of the target purity. Finally, the unreacted deuterium source is recovered in the form of deuterium gas and / or heavy water and recycled back to the anode reaction zone and / or heavy water electrolysis device and / or deuterium gas supply device. The unreacted nitrogen source is adjusted and returned to the electrochemical reaction system or front-end treatment unit to realize the recycling of reactants.

[0028] Furthermore, in step (1) above, the nitrogen source is nitrogen or air. The nitrogen source is first activated by plasma or other energy field action, and then purified and adjusted to obtain a nitrogen source suitable for electrochemical conversion on the cathode side.

[0029] Furthermore, in step (2) above, the deuterium source is heavy water or deuterium gas. The deuterium gas can be generated in situ or externally by a heavy water electrolysis device, undergoing an electrochemical reaction under an applied electric field to produce migratory deuterium nuclei. It should be noted that if the deuterium source is replaced with a common hydrogen source (such as hydrogen gas), this invention can also be applied to the synthesis of high-purity gaseous conventional ammonia.

[0030] Furthermore, in step (3) above, under the drive of an electric field, by regulating the structure and mass transfer behavior of the reaction interface, deuterium nuclei migrate directionally from the anode side to the cathode reaction interface, and undergo a one-step electrochemical conversion reaction with the nitrogen-containing species at the cathode interface to directly generate gaseous deuterated ammonia. Simultaneously, by regulating the cathode reaction interface, the deuterium nucleus supply rate is matched with the adsorption coverage of the nitrogen-containing reactants to suppress side reactions and reduce product cross-interface migration. The interface regulation methods include one or more of the following: regulating the catalyst type and structure, the cathode gas diffusion layer, the transport resistance of interface ions or neutral species, and the matching relationship between the deuterium nucleus supply rate and the adsorption coverage of nitrogen-containing species, thereby suppressing side reactions and product cross-interface migration. Through the interface regulation process, a high conversion rate, preferably close to complete conversion, is achieved in the single-pass reaction of the nitrogen-containing reactants.

[0031] Furthermore, in step (4) above, the derivation of gaseous deuterated ammonia enters the gas phase separation and purification process, specifically including condensation, adsorption / desorption, membrane separation, distillation, cryogenic separation or any combination thereof, to obtain a high-purity gaseous deuterated ammonia product with the target purity.

[0032] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention constructs an electrochemical reaction system with partitioned supply of deuterium source and nitrogen-containing reactants. No electrolyte is provided on the cathode side, while heavy water or deuterium gas is introduced as the deuterium source on the anode side, enabling an electrochemical synthesis process under gas-solid interface reaction conditions. Under the action of an applied electric field, deuterium nuclei migrate directionally from the anode side to the reaction interface, allowing gaseous nitrogen-containing species to undergo direct electrochemical conversion at the cathode interface, generating and outputting gaseous deuterated ammonia products. By designing the catalyst and controlling the deuterium nucleus supply rate at the reaction interface, side reactions and cross-interface migration of products are effectively suppressed, achieving direct gaseous generation and continuous output of deuterated ammonia.

[0033] 2. Compared with existing liquid-phase electrocatalytic synthesis systems containing electrolytes, this invention avoids the dissolution and secondary desorption process of deuterated ammonia in the electrolyte, reduces deuterium source loss and separation energy consumption, and improves deuterium utilization efficiency and product purity. While reducing energy consumption and carbon emissions, it achieves a deuterated ammonia preparation efficiency close to the single-pass conversion level of solid-phase nitride hydrolysis routes. It is also suitable for the continuous electrochemical preparation of high-purity deuterated ammonia and high-purity gas-phase conventional ammonia.

[0034] 3. This invention can avoid the liquid phase dissolution process under electrochemical conditions, realize the direct gas phase generation and output of deuterated ammonia, reduce system energy consumption and carbon emissions, improve deuterium utilization efficiency and product purity, and obtain a preparation efficiency close to the single-pass conversion level of solid phase nitride hydrolysis route, thereby meeting the needs of continuous preparation of high-purity deuterated ammonia.

[0035] 4. This invention directly generates gaseous deuterated ammonia through a one-step electrochemical reaction, avoiding liquid-phase dissolution and secondary desorption processes, thus significantly reducing system energy consumption and process complexity.

[0036] 5. This invention achieves the matching of deuterium supply and nitrogen-containing species transformation by synergistically regulating the reaction interface structure and deuterium transfer behavior, effectively suppressing side reactions and product cross-interface migration, and improving deuterium utilization efficiency and product purity.

[0037] 6. By setting a generalized ion conduction isolation structure, this invention is applicable to various types of ion conduction membranes or isolation materials, avoiding limitations on specific membrane materials and possessing good process versatility and scalability.

[0038] 7. The deuterated ammonia generated by this invention is directly output in gaseous form, which facilitates integration with subsequent gas-phase separation and purification processes, is suitable for continuous operation and engineering scale-up, and has good prospects for industrial application.

[0039] 8. The present invention introduces a deuterium source circulation device, which further improves the overall utilization efficiency of the deuterium source and reduces the system operating cost. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0041] Figure 1 A schematic diagram of the system for the direct electrochemical synthesis of gaseous deuterated ammonia; Figure 2 This is a schematic diagram of a gas-phase ammonia reactor. Figure 3 The area yield and Faraday efficiency of gas-phase deuterated ammonia under different current density conditions of the present invention are shown. Detailed Implementation

[0042] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0043] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] Example 1 Systems for the direct electrochemical synthesis of gaseous deuterated ammonia, such as... Figure 1 As shown, it includes a nitrogen source activation device, a nitrogen source purification and adjustment device, a gaseous ammonia reaction device, a gaseous ammonia export device and a gaseous ammonia separation and purification device connected in sequence, and also includes a heavy water electrolysis device and / or a deuterium gas supply device connected to the gaseous ammonia reaction device, as well as a deuterium source circulation device that is circulatedly connected to the gaseous ammonia reaction device. like Figure 2As shown, the gas-phase ammonia reactor is a flat-plate type, including an electrochemical reaction unit. The electrochemical reaction unit includes a cathode flow channel, a cathode catalyst layer, a conduction and isolation structure (proton conduction membrane), an anode catalyst layer, and an anode flow channel stacked in sequence.

[0048] In this embodiment, a nitrogen source is introduced into a nitrogen source activation unit, where it is activated by plasma to transform it into a nitrogen source component with higher reactivity. The activated nitrogen source then enters a nitrogen source purification and conditioning device, where impurities that do not participate in the reaction or are detrimental to subsequent reactions are removed or their concentration adjusted to obtain a nitrogen source suitable for electrochemical reactions. The treated nitrogen source is then introduced from the cathode side into the cathode reaction zone (cathode channel) of the gas-phase ammonia reactor. In other embodiments, readily available nitrogen-containing gas can also be directly introduced from the cathode side into the cathode reaction zone of the gas-phase ammonia reactor.

[0049] In this embodiment, heavy water is introduced into a heavy water electrolysis device to generate deuterium gas through an electrolytic reaction. The deuterium gas is introduced directly or after regulation into the anode reaction zone (anode channel) of the gas-phase ammonia reactor as a deuterium source on the anode side. In other embodiments, the deuterium source may be partially or entirely supplied directly to the anode reaction zone by heavy water, or provided by an external deuterium gas source; this invention does not limit this.

[0050] In this embodiment, the gas phase ammonia reaction device includes a cathode reaction zone and an anode reaction zone that are separated from each other. A cathode catalyst layer is provided in the cathode flow channel of the cathode reaction zone, and an anode catalyst layer is provided in the anode flow channel of the anode reaction zone. A conduction and isolation structure is provided between the two, and the voltage and current required for the electrochemical reaction are provided by an external power supply.

[0051] During the reaction, no liquid electrolyte is placed in the cathode reaction zone. The nitrogen source contacts the cathode catalyst layer and undergoes an electrochemical reaction under gas-phase or gas-solid interface conditions. On the anode side, under the action of an applied electric field, heavy water and / or deuterium undergo an electrochemical reaction to generate migratory deuterium nuclei. Driven by the electric field, the deuterium nuclei migrate directionally from the anode side to the cathode side through conduction and isolation structures, and undergo a one-step electrochemical conversion reaction with nitrogen-containing species at the cathode reaction interface to directly generate gaseous deuterated ammonia.

[0052] In this embodiment, the selectivity of deuterated ammonia formation is improved by regulating the reaction interface within the gas-phase ammonia reactor. Interface regulation methods include, but are not limited to: adjusting the composition and structure of the cathode catalyst layer, optimizing the cathode gas diffusion layer structure, adjusting the transport resistance of ions or neutral species at the ion conduction and regional isolation layers, and matching the deuterium nucleus supply rate with the adsorption coverage of nitrogen-containing species. Through these regulations, side reactions can be effectively suppressed, product cross-interface migration reduced, and deuterium utilization efficiency and the purity of gas-phase deuterated ammonia products improved.

[0053] In this embodiment, the gaseous deuterated ammonia generated by the gaseous ammonia reactor enters the gaseous ammonia separation and purification device through the gaseous ammonia export device to separate and purify the gaseous product, thereby obtaining a deuterated ammonia product of the target purity.

[0054] In this embodiment, the deuterium source that is not consumed during the reaction is recovered by the deuterium source recycling device and then returned to the gaseous ammonia reactor, thus realizing the recycling of the reactants.

[0055] In this embodiment, an external power supply provides the voltage and current required for the gaseous ammonia reactor to react, and the operating parameters such as temperature, pressure, and gas flow rate of the system are adjusted and monitored by an operation control and auxiliary device to ensure stable and continuous operation of the system.

[0056] Example 2 The electrochemical method for direct synthesis of gaseous deuterated ammonia, using the system of Example 1, specifically includes the following steps: (1) Nitrogen gas is first introduced into the nitrogen source activation device for activation, then into the nitrogen source purification and adjustment device for purification and adjustment, and finally into the gas phase ammonia reaction device. (2) First, heavy water is fed into a heavy water electrolysis device to generate deuterium gas through electrolysis reaction, and then the deuterium gas is fed into a gas phase ammonia reaction device; (3) Under the drive of an electric field, deuterium and nitrogen undergo a one-step electrochemical conversion reaction to directly generate gaseous deuterated ammonia; (4) First, the gaseous deuterated ammonia is introduced into the gaseous ammonia export device for export, and then introduced into the gaseous ammonia separation and purification device for separation and purification to obtain high-purity gaseous deuterated ammonia. (5) The deuterium gas that was not consumed during the reaction is fed into the deuterium source circulation device for recovery and then returned to the gas phase ammonia reaction device.

[0057] Example 3 The electrochemical method for direct synthesis of gaseous deuterated ammonia, using the system of Example 1, specifically includes the following steps: (1) First, the air is introduced into the nitrogen source activation device for activation, then into the nitrogen source purification and adjustment device for purification and adjustment, and finally into the gas phase ammonia reaction device. (2) Introduce deuterium gas into the gas-phase ammonia reaction apparatus; (3) Under the drive of an electric field, air and deuterium undergo a one-step electrochemical conversion reaction to directly generate gaseous deuterated ammonia; (4) First, the gaseous deuterated ammonia is introduced into the gaseous ammonia export device for export, and then introduced into the gaseous ammonia separation and purification device for separation and purification to obtain high-purity gaseous deuterated ammonia. (5) The deuterium gas that was not consumed during the reaction is fed into the deuterium source circulation device for recovery and then returned to the gas phase ammonia reaction device.

[0058] Performance testing To verify the technical effectiveness of this invention in preparing high-purity gaseous deuterated ammonia, the performance of the system of this invention (the system of Example 1 and the method of Example 2) was systematically tested using an electrochemical reaction device with a membrane electrode assembly structure.

[0059] The electrolysis apparatus used in the test was assembled from a cathode gas diffusion electrode, an anode electrode, and an ion exchange membrane, with an effective reaction area of ​​4 cm². 2 The test was conducted using a constant current method, with the test temperature controlled at 25 ± 2℃, and the reaction was carried out under normal pressure. During the test, a certain flow rate of NO gas was introduced into the cathode side as a nitrogen-containing reactant, while a deuterium source was provided on the anode side according to the system of this invention to drive the reduction reaction.

[0060] During the test, the cathode outlet product is discharged in gaseous form and enters the product collection and analysis system. By continuously passing the cathode outlet gas into an acidic absorbent of known volume and concentration, the generated gaseous deuterated ammonia is quantitatively captured. After capture, the ammonia content in the absorbent is determined by ion chromatography, thereby calculating the molar number of deuterated ammonia generated under the corresponding conditions.

[0061] The Faradaic efficiency of deuterated ammonia is calculated by comparing the theoretical charge consumed in the formation of deuterated ammonia with the actual charge passing through the electrolyzer during the reaction. Since the reduction of nitric oxide to deuterated ammonia is a five-electron transfer reaction, the obtained Faradaic efficiency directly reflects the selectivity of electron transfer to the target product during the reaction.

[0062] Based on this, the mass of deuterated ammonia generated per unit time within a unit electrode area is calculated according to the applied current density, reaction time, and amount of deuterated ammonia generated, thereby obtaining the area yield of gaseous deuterated ammonia, which is used to evaluate the actual production capacity of the system of the present invention under high current density conditions.

[0063] The system of the present invention was tested under different current density conditions. Figure 3 The results show that within the range of 200-1000 mA·cm -2 Stable gas-phase deuterated ammonia formation can be achieved over a wide current density range. With increasing current density, the area yield of gas-phase deuterated ammonia increases significantly, while the Faraday efficiency remains consistently high, indicating that the system of this invention still exhibits good reaction selectivity and product formation capability under high current density conditions.

[0064] The test results above show that the present invention can directly generate and collect deuterated ammonia in high-purity gas phase during the electrochemical reaction process. It not only has high Faraday efficiency and yield, but also shows significant advantages in isotope purity and reaction stability, which fully demonstrates the technical effect of the present invention in the field of high-purity gas phase deuterated ammonia preparation.

[0065] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A system for electrochemical direct synthesis of gaseous deuterated ammonia, characterized in that, It includes a nitrogen source activation device, a nitrogen source purification and regulation device, a gaseous ammonia reaction device, a gaseous ammonia export device, and a gaseous ammonia separation and purification device connected in sequence.

2. The system for electrochemical direct synthesis of gaseous deuterated ammonia according to claim 1, characterized in that, The gas-phase ammonia reactor has a flat-plate structure.

3. The system for the direct electrochemical synthesis of gaseous deuterated ammonia according to claim 1, characterized in that, The gas-phase ammonia reaction device includes an electrochemical reaction unit.

4. The system for the direct electrochemical synthesis of gaseous deuterated ammonia according to claim 3, characterized in that, The electrochemical reaction unit comprises a cathode flow channel, a cathode catalyst layer, a conductive and insulating structure, an anode catalyst layer, and an anode flow channel stacked sequentially.

5. The system for the direct electrochemical synthesis of gaseous deuterated ammonia according to claim 4, characterized in that, The conduction and isolation structure is a proton conduction membrane.

6. The system for the direct electrochemical synthesis of gaseous deuterated ammonia according to claim 1, characterized in that, It also includes a heavy water electrolysis device and / or a deuterium supply device connected to the gaseous ammonia reactor.

7. The system for the direct electrochemical synthesis of gaseous deuterated ammonia according to claim 1, characterized in that, It also includes a deuterium source circulation device that is cyclically connected to the gaseous ammonia reactor.

8. A method for the direct electrochemical synthesis of gaseous deuterated ammonia, characterized in that, The system described in claim 1 specifically includes the following steps: (1) First, the nitrogen source is activated by the nitrogen source activation device, then purified and regulated by the nitrogen source purification and regulation device, and finally introduced into the gas phase ammonia reaction device. (2) Introduce the deuterium source into the gas-phase ammonia reaction apparatus; (3) Under the drive of an electric field, the deuterium source and the nitrogen source undergo a one-step electrochemical conversion reaction to directly generate gaseous deuterated ammonia; (4) First, the gaseous deuterated ammonia is introduced into the gaseous ammonia export device for export, and then introduced into the gaseous ammonia separation and purification device for separation and purification to obtain high-purity gaseous deuterated ammonia.

9. The method for direct electrochemical synthesis of gaseous deuterated ammonia according to claim 8, characterized in that, In step (1), the nitrogen source is nitrogen or air.

10. The method for direct electrochemical synthesis of gaseous deuterated ammonia according to claim 8, characterized in that, In step (2), the deuterium source is heavy water or deuterium gas.

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