Method for electrochemical synthesis of ammonia and polymer solid electrolyte used

Abstract

The application relates to the technical field of materials, in particular to a polymer solid electrolyte, which is a sulfonated polyether ether ketone (SPEEK) polymer solid electrolyte containing nano titanium dioxide (TiO2) filler. The application also provides a preparation method of the polymer solid electrolyte. The application also provides an electrochemical synthesis ammonia method using the polymer solid electrolyte. The application develops a polymer solid electrolyte which can be used in the electrochemical synthesis ammonia under normal pressure, and the ammonia yield of the polymer solid electrolyte can be improved under low-temperature (80-120 DEG C) reaction conditions.

Description

Technical Field

[0001] This invention relates to the field of materials technology, specifically to a method for electrochemical synthesis of ammonia and a method for preparing a SPEEK polymer solid electrolyte containing nano-TiO2 filler. Background Technology

[0002] Solid electrolytes are solid conductive materials that conduct electricity through ion displacement. Due to defects in the crystal lattice, these materials have good conductivity at high temperatures, which can promote reaction kinetics, improve the current efficiency and stability of catalysts, and obtain higher ammonia production rates. They are being explored for application in electrocatalytic ammonia synthesis reactions.

[0003] Solid electrolytes used in the electrochemical synthesis of ammonia include proton conductors and oxygen ion conductors. In recent years, extensive research has been conducted on proton conductors as electrolytes for the electrochemical synthesis of ammonia. Chen et al. (Journal of Alloys and Compounds, 2009, 485(1):69-72) synthesized Gd-doped BaCeO3 (BaCeO3) using a microemulsion method. 0.85 Gd 0.15 O 3-δ Using BCGO as the electrolyte, Ni-BCGO and Ag-Pd alloys as the anode and cathode respectively, and N2 and H2 as the reactants, the ammonia generation rate at 480℃ is 4.63 × 10⁻⁶. -9 mol cm -2 s -1 Similarly, Liu et al. (SolidState Ionics, 2006, 177(1-2):73-76) adopted Ce 0.8 Sm 0.2 O 2-δ Using SDC as the electrolyte and Ag-Pd alloy as the electrode, the ammonia generation rate at 650℃ is 8.2 × 10⁻⁶. -9 mol·cm- 2 ·s -1 However, commonly used proton conductors such as perovskite, pyrochlore, and fluorite require relatively high operating temperatures to exhibit high proton conductivity. To lower the operating temperature of electrochemical ammonia synthesis, composite proton conductors and polymer materials are used as electrolytes. Lan et al. (Science Reports, 2013, 3:1-7) used H... + / NH4 + Using a Nafion 211 membrane as the electrolyte and Pt / C as the catalysts for both the cathode and anode, the electrochemical synthesis of ammonia with different reactants was investigated at room temperature. When N2 and H2 were used as reactants, the ammonia formation rate reached 3.1 × 10⁻⁶. -9mol·cm -2 ·s -1 When air and H2O are reactants, the ammonia formation rate is 1.14 × 10⁻⁶. - 9 mol·cm -2 ·s -1 This method enables the direct electrochemical synthesis of ammonia from air and H2O at room temperature and pressure. However, due to the limitation of low temperature, the ammonia production rate is relatively low.

[0004] Based on existing literature and technology, the use of solid electrolytes in the electrochemical synthesis of ammonia mostly employs high-temperature proton conductors, which are carried out under high-temperature conditions (i.e., high temperature), require a lot of energy, and are not conducive to the collection of the product ammonia.

[0005] The current method for electrochemically synthesizing ammonia using nitrogen and water as raw materials uses an aqueous electrolyte, which results in a severe competing reaction for hydrogen evolution, leading to a decrease in reaction selectivity. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a green and mild method for synthesizing ammonia using nitrogen and water electrochemically, and the polymer solid electrolyte used therein.

[0007] To address the aforementioned technical problems, this invention provides a polymer solid electrolyte, which is a sulfonated polyether ether ketone (SPEEK) polymer solid electrolyte containing nano-titanium dioxide (TiO2) filler.

[0008] The present invention also provides a method for preparing the above-mentioned polymer solid electrolyte, comprising the following steps:

[0009] 1) Under the protection of an inert gas (such as nitrogen), polyether ether ketone (PEEK) is sulfonated with sulfuric acid (concentrated sulfuric acid) to obtain sulfonated polyether ether ketone (SPEEK).

[0010] 2) Dissolve 10g of sulfonated polyether ether ketone (SPEEK) in an ethanol / water solution at 60-80℃ to obtain a polymer solution;

[0011] 3) Disperse 0.5-5g (preferably 0.8-2g) of nano-titanium dioxide (TiO2) filler in 50±10mL of ethanol to obtain a TiO2 dispersion;

[0012] 4) Under stirring conditions, add the TiO2 dispersion obtained in step 3) to the polymer solution obtained in step 2) (add slowly, with the addition time controlled at 30-60 seconds). After the addition is complete, continue stirring for 12±2h to ensure thorough mixing.

[0013] 5) Add 0.8-1.2g of ammonium hydrogen nitrate (NH4NO3) to the mixed solution obtained in step 4) and stir until homogeneous (so that the ammonia ions are evenly distributed in the polymer); then pour it into a flat-bottomed container (keeping the liquid depth at about 2-4mm) and let it stand (for about 24-48 hours) to evaporate the solvent (ethanol and water) and form a uniform polymer film.

[0014] 6) Dry the polymer film obtained in step 5) at 70-90°C to constant weight;

[0015] The dried film was then treated in boiling water for 1 ± 0.1 h (to activate its proton conductivity) to obtain the SPEEK / TiO2 solid electrolyte film as a polymer solid electrolyte.

[0016] As an improvement to the preparation method of the polymer solid electrolyte of the present invention: in the ethanol / water solution of step 2), the volume ratio of ethanol to water is 1:0.9 to 1.1 (preferably 1:1).

[0017] As a further improvement to the preparation method of the polymer solid electrolyte of the present invention, step 1) is as follows:

[0018] Dissolve 100g of polyether ether ketone (PEEK) in 280-320mL (preferably 300mL) of concentrated sulfuric acid and stir at room temperature for 24±2h to achieve sulfonation reaction;

[0019] After the reaction is complete, the reaction mixture is poured into ice water (excess ice water) to terminate the reaction. The resulting precipitate is washed with water (repeatedly with distilled water until the washing solution is neutral), and then vacuum dried (vacuum dried at 50-70°C to constant weight) to obtain sulfonated polyether ether ketone (SPEEK).

[0020] As a further improvement to the preparation method of the polymer solid electrolyte of the present invention, step 2) is as follows:

[0021] At 60–80°C, 10 g of sulfonated polyether ether ketone (SPEEK) was added to 900–1100 mL of ethanol / water solution and stirred for 24 ± 2 h to obtain a polymer solution.

[0022] As a further improvement to the preparation method of the polymer solid electrolyte of the present invention, in step 3):

[0023] Nano-titanium dioxide (TiO2) was added to ethanol and dispersed (using ultrasonic dispersion) at a material-to-liquid ratio of 0.8–2 g / 50 mL ethanol to obtain a TiO2 dispersion (a uniformly dispersed TiO2 dispersion).

[0024] This invention also provides a method for electrochemically synthesizing ammonia using the polymer solid electrolyte prepared by the above method, comprising the following steps:

[0025] 1. An electrolytic cell is established between the anode and the cathode. A SPEEK / TiO2 solid electrolyte membrane is placed in the electrolytic cell as the electrolyte. The SPEEK / TiO2 solid electrolyte membrane divides the electrolytic cell into the cathode side and the anode side.

[0026] 2. A mixed gas containing nitrogen and water vapor is introduced to the cathode side of the electrolytic cell, and electrolysis is carried out at a set potential and temperature to promote the electrochemical reaction between nitrogen and water to generate ammonia; at the same time, proton (hydrogen ion) transport occurs in the electrolyte to maintain the reaction; the ammonia generated during the electrochemical synthesis is collected.

[0027] Explanation: In this invention, the SPEEK / TiO2 solid electrolyte membrane acts as an separator in the electrolytic cell, separating the nitrogen and water vapor mixture on the cathode side from the gas (generated oxygen) on the anode side. Nitrogen serves as the reactant, and water serves as the proton source and water molecules in the electrolyte. Ammonia is generated on the cathode side of the electrolytic cell through an electrochemical reaction between nitrogen and water, and is discharged from the cathode side with the gas flow. After gas-liquid separation, the ammonia is collected using conventional condensation equipment, and the yield is calculated by detection (gas chromatography-mass spectrometry).

[0028] As an improvement to the electrochemical ammonia synthesis method of the present invention:

[0029] The volume ratio of nitrogen to water is 1:3;

[0030] The potential range is set to -5.0 to 0V (preferably -1.0 to -2.0V), and the reaction temperature is set to 80 to 120℃ (preferably 80 to 100℃).

[0031] The reaction time (electrolysis time) can be set to, for example, 10 to 20 hours.

[0032] To develop a milder process, this invention uses nitrogen and water as raw materials to develop a polymer solid electrolyte that can be used for electrochemical ammonia synthesis under normal pressure, which can increase ammonia production under low temperature (80-120°C) reaction conditions.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] 1) By introducing nano-titanium dioxide (TiO2) into the polymer electrolyte, the proton conductivity is significantly improved, thereby increasing the efficiency of the electrochemical reaction.

[0035] 2) Nano-TiO2 filler enhances the mechanical strength of the polymer film, increasing the tensile strength of the polymer film from 20MPa without filler to 45MPa. At the same time, it improves the chemical stability of the polymer film, and the performance still retains more than 95% of the original after 500 hours of use.

[0036] 3) SPEEK electrolytes enable the reaction system to operate at lower temperatures (80-120℃), reducing energy consumption and material costs.

[0037] 4) The use of solid electrolytes in this invention can avoid side reactions caused by the presence of water and effectively improve selectivity. Detailed Implementation

[0038] The embodiments of the present invention will be described in detail below. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes.

[0039] In this invention: the particle size of nano-titanium dioxide (TiO2) is 10-50 nanometers; the concentration of concentrated sulfuric acid is 98%.

[0040] Example 1: A method for preparing a SPEEK / TiO2 solid electrolyte thin film:

[0041] 1) Under nitrogen protection, dissolve 100g of polyether ether ketone (PEEK) in 300mL of concentrated sulfuric acid and stir at room temperature for 24 hours to achieve sulfonation.

[0042] After the reaction was complete, the resulting reaction mixture was poured into an excess (1000 mL) of ice water to terminate the reaction, and a precipitate was obtained. The precipitate was washed repeatedly with distilled water until the washings were neutral. The washed precipitate was dried in a vacuum drying oven (60 °C vacuum drying to constant weight) and sulfonated polyether ether ketone (SPEEK) for later use.

[0043] 2) Dissolve 10g of SPEEK in a mixed solution of 500mL distilled water and 500mL ethanol, and stir at 60℃ for 24h to form a homogeneous polymer solution.

[0044] 3) Disperse 1g of nano-titanium dioxide (TiO2) filler in 50mL of ethanol and treat it with ultrasound for 30 minutes to ensure that TiO2 is uniformly dispersed in ethanol; obtain TiO2 dispersion.

[0045] 4) Under stirring conditions, slowly add the TiO2 dispersion obtained in step 3) to the polymer solution obtained in step 2), and control the slow addition time to 30-60 seconds to ensure that the nano TiO2 is uniformly distributed in the polymer solution; after the addition is completed, continue stirring for 12 hours to ensure thorough mixing.

[0046] 5) Add 1g of ammonium hydrogen nitrate (NH4NO3) to the mixed solution obtained in step 4), stir evenly to make the ammonia ions evenly distributed in the polymer; then pour it into a flat-bottomed glass container (keeping the solution depth at about 2mm), and let it stand for about 24 hours to evaporate the solvent (ethanol and water) and form a uniform polymer film.

[0047] 6) Dry the polymer film obtained in step 5) at 80°C to constant weight to remove moisture;

[0048] The dried film was treated in boiling water for 1 hour to activate its proton conductivity, thus obtaining a SPEEK / TiO2 solid electrolyte film.

[0049] Note: Drying to constant weight at 80℃ not only removes most of the moisture and solvent residue, but also ensures uniform drying, preventing stress concentration or microcracks caused by uneven distribution of moisture or solvent in the membrane. This ensures the membrane is less prone to defects such as breakage in subsequent processing steps. In other words, pre-drying allows the membrane to maintain a more stable structure when entering boiling water treatment, avoiding sudden volume changes and ensuring the controllability of the treatment process and the final performance of the membrane.

[0050] Experiment 1: Electrochemical Synthesis of Ammonia

[0051] Referring to the battery test system used in Example 1 of CN202111139571.X, "A Solid Electrolyte for Electrocatalytic Oxygen Reduction Synthesis of Hydrogen Peroxide and Its Preparation Method", an electrolytic cell was established between the anode and the cathode. Carbon black was sprayed onto the anion exchange membrane on the cathode, and 60% Pt / C was sprayed onto the proton exchange membrane on the anode. The prepared SPEEK / TiO2 solid electrolyte film was placed in the electrolytic cell as the electrolyte. The SPEEK / TiO2 solid electrolyte film separated the electrolytic cell into the cathode side and the anode side.

[0052] A mixture of nitrogen and water vapor (nitrogen to water volume ratio 1:3) is introduced into the cathode side of the electrolytic cell at a flow rate of 50 mL / min. The SPEEK / TiO2 solid electrolyte membrane acts as an separator in the electrolytic cell, separating the nitrogen and water vapor mixture on the cathode side from the gas (generated oxygen) on the anode side. Nitrogen serves as the reactant, and water serves as the proton source and water molecules in the electrolyte. Electrolysis is carried out for 10 hours at a set potential of -1.0 V and a reaction temperature of 100 °C, promoting the electrochemical reaction between nitrogen and water to generate ammonia.

[0053] Ammonia is generated on the cathode side of the electrolytic cell through an electrochemical reaction of nitrogen and water, and is discharged from the cathode side along with the gas stream. After gas-liquid separation, the ammonia is collected using conventional condensation equipment, and the yield is calculated by monitoring. The ammonia generation rate is found to be 9.5 × 10⁻⁶. -8 mol·cm -2 ·s -1 .

[0054] The detection can be performed using gas chromatography-mass spectrometry (GC-MS). A gas mixture (including nitrogen and ammonia) is passed into a gas chromatograph, and then the mass spectrometer detects the characteristic mass spectrometric peaks of ammonia. The amount of ammonia generated is calculated based on the peak area.

[0055] Formula for calculating the ammonia generation rate y NH3 =n NH3 / (A×t).

[0056] n NH3 The moles of ammonia produced (mol) are given, and A is the effective area of ​​the electrode (i.e., the cathode area of ​​the battery, cm²). 2 ), where t is the reaction time in seconds.

[0057] Example 2: A method for preparing a SPEEK / TiO2 solid electrolyte thin film, with the following changes compared to Example 1:

[0058] Change the stirring temperature in step 2) from "60℃" to "70℃";

[0059] The rest is the same as in Example 1.

[0060] The SPEEK / TiO2 solid electrolyte film obtained in Example 2 was used to electrochemically synthesize ammonia according to Experiment 1, and the ammonia generation rate was 9.2 × 10⁻⁶. -8 mol·cm -2 ·s -1 .

[0061] Example 3: A method for preparing a SPEEK / TiO2 solid electrolyte thin film, with the following changes compared to Example 1:

[0062] In step 3), the amount of nano-titanium dioxide (TiO2) filler was changed from "1g" to "0.8g", and the rest was the same as in Example 1.

[0063] The SPEEK / TiO2 solid electrolyte film obtained in Example 3 was used to electrochemically synthesize ammonia according to Experiment 1, and the ammonia generation rate was 8.5 × 10⁻⁶. -8 mol·cm -2 ·s -1 .

[0064] Example 4: The preparation method of SPEEK / TiO2 solid electrolyte film is modified compared to Example 1 as follows:

[0065] In step 3), the amount of nano-titanium dioxide (TiO2) filler was changed from "1g" to "2g", and the rest was the same as in Example 1.

[0066] The SPEEK / TiO2 solid electrolyte film obtained in Example 3 was used to electrochemically synthesize ammonia according to Experiment 1, and the ammonia generation rate was 6.7 × 10⁻⁶. -8 mol·cm -2 ·s -1 .

[0067] Experiment 2: Change the reaction temperature in Experiment 1 from "100℃" to "90℃", and keep the rest the same as Experiment 1.

[0068] The SPEEK / TiO2 solid electrolyte films obtained in Examples 1 and 2 were used to electrochemically synthesize ammonia according to Experiment 2. The results are shown in Table 1 below.

[0069] Experiment 3: Change the set potential in Experiment 1 from "-1.0V" to "-2.0V" and change the reaction temperature from "100℃" to "80℃"; the rest is the same as Experiment 1.

[0070] The SPEEK / TiO2 solid electrolyte films obtained in Examples 1 and 2 were used to electrochemically synthesize ammonia according to Experiment 3. The results are shown in Table 1 below.

[0071] Compared with Experiment 1, the reaction temperature in Experiment 1 was changed from "100℃" to "20℃"; the rest is the same as Experiment 1.

[0072] The SPEEK / TiO2 solid electrolyte film obtained in Example 1 was used to electrochemically synthesize ammonia according to Comparative Experiment 1, and the ammonia generation rate was 1.2 × 10⁻⁶. -10 mol·cm -2 ·s -1 。

[0073] Table 1. Ammonia generation rates of different solid electrolyte films under different experimental conditions (mol·cm⁻¹) -2 ·s -1 )

[0074] Example 1 Example 2 Example 3 Example 4 Experiment 1 <![CDATA[9.5×10 -8 ]]> <![CDATA[9.2×10 -8 ]]> <![CDATA[8.5×10 -8 ]]> <![CDATA[6.7×10 -8 ]]> Experiment 2 <![CDATA[8.5×10 -8 ]]> <![CDATA[8.7×10 -8 ]]> / / Experiment 3 <![CDATA[8.2×10 -8 ]]> <![CDATA[8.3×10 -8 ]]> / / Comparative Experiment 1 <![CDATA[1.2×10 -10 ]]> / / /

[0075] Note: " / " indicates that the experiment was not conducted.

[0076] Comparative Example 1: Preparation of SPEEK solid electrolyte thin films:

[0077] The following changes were made compared to Example 1:

[0078] Cancel steps 3) and 4);

[0079] That is, 1g of ammonium hydrogen nitrate (NH4NO3) is added directly to the polymer solution obtained in step 2);

[0080] The rest is the same as in Example 1; a SPEEK solid electrolyte film is obtained.

[0081] The SPEEK solid electrolyte membrane obtained in Comparative Example 1 was used to electrochemically synthesize ammonia according to Experiment 1, and the ammonia generation rate was 1.8 × 10⁻⁶. -9 mol·cm -2 ·s -1 .

[0082] Comparative Example 2: The filler in Example 1 was changed from nano titanium dioxide (TiO2) to nano CeO2, while the amount remained unchanged at 1g, and the rest was the same as in Example 1.

[0083] The SPEEK / CeO2 solid electrolyte membrane obtained in Comparative Example 2 was used for electrochemical ammonia synthesis according to Experiment 1, and the ammonia generation rate was 1.5 × 10⁻⁶. -9 mol·cm -2 ·s -1 .

[0084] Comparative Example 3-1: The amount of "ammonium hydrogen nitrate (NH4NO3)" in step 5) of Example 1 was changed from "1g" to "1.5g", and the rest was the same as in Example 1.

[0085] The SPEEK / TiO2 solid electrolyte film obtained in Comparative Example 3-1 was used to electrochemically synthesize ammonia according to Experiment 1, and the ammonia generation rate was 2.8 × 10⁻⁶. -9 mol·cm -2 ·s -1 .

[0086] Comparative Example 3-2: The amount of "ammonium hydrogen nitrate (NH4NO3)" in step 5) of Example 1 was changed from "1g" to "0.5g", and the rest was the same as in Example 1.

[0087] The SPEEK / TiO2 solid electrolyte film obtained in 3-2 was used for electrochemical synthesis of ammonia according to Experiment 1, and the ammonia generation rate was 2.9 × 10⁻⁶. -9 mol·cm -2 ·s -1 .

[0088] Comparative Example 4: The step 6) of Example 1 is omitted, which is to say, the product obtained in step 5) is directly subjected to boiling water treatment, and the rest is the same as in Example 1.

[0089] The SPEEK / TiO2 solid electrolyte film obtained in Comparative Example 4 was used to electrochemically synthesize ammonia according to Experiment 1, and the ammonia generation rate was 5.8 × 10⁻⁶. -9 mol·cm -2 ·s -1 .

[0090] Comparative Example 5: The amount of "nano titanium dioxide (TiO2) filler" in step 3) of Example 1 was changed from "1g" to "0.2g", and the rest was the same as in Example 1.

[0091] The SPEEK / TiO2 solid electrolyte film obtained in Comparative Example 5 was used to electrochemically synthesize ammonia according to Experiment 1, and the ammonia generation rate was 1.6 × 10⁻⁶. -10 mol·cm -2 ·s -1 .

[0092] Comparative Example 6: The "500 mL distilled water and 500 mL ethanol" in Example 1 were changed to "300 mL distilled water and 700 mL ethanol", and the rest were the same as in Example 1.

[0093] The SPEEK / TiO2 solid electrolyte film obtained in Comparative Example 6 was used to electrochemically synthesize ammonia according to Experiment 1, and the ammonia generation rate was 3.6 × 10⁻⁶. -10 mol·cm -2 ·s -1

[0094] Experiment 4, Stability Comparison:

[0095] The SPEEK / TiO2 solid electrolyte film obtained in Example 1 was used to electrochemically synthesize ammonia according to Experiment 1. After 500 hours of continuous use, the ammonia generation rate still remained above 95% of the original rate.

[0096] However, when the SPEEK solid electrolyte membrane obtained in Comparative Example 1 was used to electrochemically synthesize ammonia according to Experiment 1, the ammonia generation rate could only be maintained at 56% of the original rate after 500 hours of continuous use.

[0097] Finally, it should be noted that the above examples are merely some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A polymer solid electrolyte, characterized in that: It is a sulfonated polyether ether ketone polymer solid electrolyte containing nano-titanium dioxide filler; The preparation method of polymer solid electrolyte includes the following steps: 1) Under the protection of an inert gas, polyether ether ketone is sulfonated with sulfuric acid to obtain sulfonated polyether ether ketone. 2) Dissolve 10g of sulfonated polyether ether ketone in 900-1100mL of ethanol / water solution at 60-80℃ to obtain a polymer solution; In an ethanol / water solution, the volume ratio of ethanol to water is 1:0.9~1.

1. 3) Disperse 0.5~5 g of nano-titanium dioxide filler in 50±10 mL of ethanol to obtain TiO2 dispersion; 4) Under stirring conditions, add the TiO2 dispersion obtained in step 3) to the polymer solution obtained in step 2). After the addition is complete, continue stirring for 12±2 h to ensure thorough mixing. 5) Add 0.8~1.2g of ammonium hydrogen nitrate to the mixed solution obtained in step 4) and stir until homogeneous; then pour into a flat-bottomed container and let stand to evaporate the solvent to form a polymer film; 6) Dry the polymer film obtained in step 5) at 70~90℃ to constant weight; The dried film was then treated in boiling water for 1 ± 0.1 h to obtain the SPEEK / TiO2 solid electrolyte film as a polymer solid electrolyte.

2. The polymer solid electrolyte according to claim 1, characterized in that... Step 1) is as follows: Dissolve 100 g of polyether ether ketone in 280 ~ 320 mL of concentrated sulfuric acid and stir at room temperature for 24 ± 2 h to achieve sulfonation reaction; After the reaction was completed, the reaction mixture was poured into ice water to terminate the reaction. The resulting precipitate was washed with water and then dried under vacuum to obtain sulfonated polyether ether ketone.

3. The polymer solid electrolyte according to claim 2, characterized in that... In step 3): Nano-titanium dioxide was added to ethanol and dispersed at a material-to-liquid ratio of 0.8~2g / 50 mL ethanol to obtain a TiO2 dispersion.

4. A method for electrochemical synthesis of ammonia using the polymer solid electrolyte as described in any one of claims 1 to 3, characterized in that... Includes the following steps:

1. An electrolytic cell is established between the anode and the cathode. A SPEEK / TiO2 solid electrolyte membrane is placed in the electrolytic cell as the electrolyte. The SPEEK / TiO2 solid electrolyte membrane divides the electrolytic cell into the cathode side and the anode side.

2. A mixed gas containing nitrogen and water vapor is introduced to the cathode side of the electrolytic cell, and electrolysis is carried out at a set potential and temperature to promote the electrochemical reaction between nitrogen and water to generate ammonia; at the same time, proton transport occurs in the electrolyte to maintain the reaction; the ammonia generated during the electrochemical synthesis is collected.

5. The method for electrochemical synthesis of ammonia according to claim 4, characterized in that: The volume ratio of nitrogen to water is 1:3; The potential range is set to -5.0~0 V, and the reaction temperature is set to 80~120℃.

6. The method for electrochemical synthesis of ammonia according to claim 5, characterized in that: Potential -1.0~-2.0 V, reaction temperature 80~100℃.