Modified electrolyte for alkaline electrolyzed water

Abstract

The invention discloses a modified electrolyte for alkaline electrolyzed water, the modified electrolyte comprises an alkaline electrolyte solution, and molybdate, sodium selenate and lithium hydroxide which are added into the alkaline electrolyte solution, and the modified electrolyte is generated by adding the molybdate, the sodium selenate and the lithium hydroxide into the alkaline electrolyte solution and stirring and dissolving the solution. Through the mode, the modified electrolyte for alkaline electrolyzed water can form NiMo, NiMoSe and other metal compounds on the surface of an electrode, so that the material composition and the surface morphology structure of the electrode are changed, more active sites are exposed, and the electrolysis efficiency of the electrode is improved.

Description

Technical Field

[0001] This invention relates to the field of alkaline water electrolysis for hydrogen production technology, and in particular to a modified electrolyte for alkaline water electrolysis. Background Technology

[0002] The excessive consumption of non-renewable energy sources has exacerbated the energy crisis and environmental pollution problems. To address these crises, developing clean and renewable energy sources to alleviate energy supply and demand imbalances and improve environmental conditions is urgently needed. Among the new energy sources currently being explored, including hydrogen, geothermal, tidal, wind, and solar energy, hydrogen, with its high calorific value per unit mass, reaction product consisting only of water, and zero pollutant emissions, is gradually becoming a highly promising and ideal clean energy source. As a highly efficient and clean technology for scalable production of high-purity hydrogen, water electrolysis for hydrogen production holds great promise. Alkaline water electrolysis for hydrogen production, with its simple process and strong cost controllability, is not only the initial exploration direction in the field of water electrolysis for hydrogen production but also the mainstream technology route with the highest commercial maturity and the most prominent industrial-scale development within this technology system.

[0003] In alkaline water electrolysis for hydrogen production, the energy consumption of the electrolysis system is a core technical indicator. Lower energy consumption not only reduces the operating cost of the electrolyzer but is also crucial for lowering the cost of hydrogen production. In principle, reducing electrode overpotential, diaphragm resistance, or electrolyte resistance can all reduce electrolyzer energy consumption. Electrode overpotential is affected by electrode materials, coating processes, solution composition, temperature, and current density. Using precious metal electrodes or optimizing electrode coatings is complex and costly. In contrast, adjusting the composition of the alkaline electrolyte and directly introducing additives is simpler and less expensive.

[0004] Literature review revealed that Li + The mobility is higher than K + It can significantly improve conductivity while suppressing side reactions on the electrode surface, and Li + The introduction of iron promotes charge transfer, thus adding LiOH to the KOH electrolyte reduces electrolysis energy consumption. However, the effect of adding LiOH on improving ionic conductivity and reducing energy consumption is limited. Meanwhile, the introduction of iron into the electrolyte has a significant impact on electrode performance in alkaline water electrolysis. For nickel-based anodes, the presence of iron is required to achieve and maintain a low overpotential in the oxygen evolution reaction (OER). However, during hydrogen evolution, the presence of iron leads to cathode deactivation.

[0005] Studies have found that while adding additives to the electrolyte can significantly reduce the energy consumption of the electrolyzer, these additives have limitations in energy reduction or can negatively impact the electrodes. Secondly, during the electrolysis of the catalyst, bubbles adhere to the catalyst surface, limiting the contact between the catalyst and the electrolyte, leading to a decrease in electrolysis efficiency. Summary of the Invention

[0006] In order to overcome the defects and shortcomings of the existing technology, this application provides a method that can significantly reduce the energy consumption of the electrolyzer, enhance charge transport, improve the conductivity of the electrolyte, promote the desorption of bubbles on the catalyst surface, suppress side reactions on the electrode surface, and avoid the problem of electrode deactivation due to the addition of metal salts.

[0007] A modified electrolyte for alkaline water electrolysis is provided, comprising an alkaline electrolyte solution and molybdate, sodium selenate, and lithium hydroxide added to the alkaline electrolyte solution. The modified electrolyte is generated by adding molybdate, sodium selenate, and lithium hydroxide to the alkaline electrolyte solution and stirring to dissolve them. The concentration of molybdate in the modified electrolyte is 0.01 mol / L to 1 mol / L, the concentration of sodium selenate additive is 0.0005 mol / L to 0.1 mol / L, and the concentration of lithium hydroxide additive in the electrolyte solution is 0.01 mol / L to 1 mol / L.

[0008] In a preferred embodiment of the present invention, the alkaline electrolyte solution is a potassium hydroxide solution or a sodium hydroxide solution.

[0009] In a preferred embodiment of the present invention, the alkaline electrolyte solution contains 15 wt% to 45 wt% potassium hydroxide or sodium hydroxide.

[0010] In a preferred embodiment of the present invention, the molybdate additive is one of potassium molybdate, sodium molybdate, calcium molybdate, ammonium molybdate, ammonium heptamolybdate, barium molybdate, lead molybdate, zinc molybdate, lanthanum molybdate, and yttrium molybdate.

[0011] The beneficial effects of this invention are as follows: During the activation process, the modified electrolyte of this application can form metal compounds such as NiMo and NiMoSe on the electrode surface, changing the material composition and surface morphology of the electrode, exposing more active sites, and improving the electrolysis efficiency of the electrode, thereby significantly reducing the overpotential of hydrogen evolution at the cathode and oxygen evolution at the anode; at the same time, the addition of lithium hydroxide is beneficial to improving the conductivity of the electrolyte, and because lithium ions have a smaller ionic radius, Li... ⁺ The small ionic radius and high mobility of the ions enhance charge transport and can simultaneously suppress side reactions on the electrode surface. The introduction of Se affects the surface and interface properties of the electrode, including enhancing surface roughness, promoting the rapid nucleation and desorption of smaller oxygen bubbles, and reducing diffusion restriction caused by bubbles. The addition of the above substances jointly promotes the reduction of energy consumption in the electrolysis reaction. Moreover, the preparation of this electrolyte is simple. It is only necessary to add a certain amount of additives to the prepared electrolyte or to add a certain amount of additives to the electrolyte of the electrolytic cell in operation at regular intervals, which is beneficial to improving work efficiency and production capacity. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a microscopic morphology diagram of the weld interface without the addition of nanocomposite materials in the existing technology; Figure 2 This is a microscopic morphology diagram of the solder joint interface in Embodiment 2 of the present invention. Detailed Implementation

[0013] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0014] Please see Figure 1-2 The embodiments of the present invention include: Comparative Example 1 A 1M potassium hydroxide aqueous solution was used as the electrolyte for the hydrogen evolution overpotential and oxygen evolution overpotential of the test electrodes (blank control electrolyte).

[0015] (1) Cut a 1cm*1cm, 1mm thick 46-mesh nickel mesh coated with Raney nickel as the working electrode and pre-treat the electrode with alkaline washing. (2) Preparation of electrolyte: 1M potassium hydroxide aqueous solution was used as electrolyte (blank control electrolyte); (3) CV activation of the electrode: The 46-mesh nickel mesh electrode coated with Raney nickel was immersed in the modified electrolyte. The working electrode was a 46-mesh nickel mesh coated with Raney nickel, the counter electrode was a graphite rod, and the reference electrode was Hg / HgO. The electrode was subjected to CV activation treatment with an activation voltage range of -1.0V to 1.0V, a scanning rate of 0.001mV / s, and 10 scans. Subsequently, the electrode was subjected to LSV testing at room temperature (25℃). The HER test voltage range of the working electrode was 0V to -0.8V (vsRHE), and the OER test voltage range of the working electrode was 0V to 1.0V (vsRHE).

[0016] Comparative Example 2 A 30 wt% potassium hydroxide aqueous solution was used as the electrolyte for testing the electrolytic cell (blank control electrolyte).

[0017] (1) Select a 46-mesh nickel mesh coated with Raney nickel as the working electrode and perform alkaline washing pretreatment on the electrode; (2) Preparation of electrolyte: The modified electrolyte was obtained by stirring and dissolving the electrolyte in 30wt% KOH solution; (3) The 46-mesh nickel mesh electrodes coated with Raney nickel were used as the anode and cathode of the electrolytic cell, respectively, and assembled into the electrolytic cell. Then, the modified electrolyte was added to the alkaline tank of the electrolytic cell system, and a current density of 5000 A / m was applied. 2 DC power supply.

[0018] Comparative Example 3 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0019] (1) Cut a 1cm*1cm, 1mm thick 46-mesh nickel mesh coated with Raney nickel as the working electrode and pre-treat the electrode with alkaline washing. (2) Preparation of electrolyte: Potassium molybdate and lithium hydroxide were added to 1 M KOH solution and stirred to dissolve them to obtain modified electrolyte; the concentration of potassium molybdate in the solution was 0.05 mol / L and the concentration of lithium hydroxide in the solution was 0.5 mol / L. (3) CV activation of the electrode: The 46-mesh nickel mesh electrode coated with Raney nickel was immersed in the modified electrolyte. The working electrode was the 46-mesh nickel mesh coated with Raney nickel, the counter electrode was a graphite rod, and the reference electrode was Hg / HgO. The electrode was subjected to CV activation treatment with an activation voltage range of -1.0V to 1.0V, a scanning rate of 0.001mV / s, and 10 scans to obtain the NiMo bimetallic catalyst. Subsequently, the electrode was subjected to LSV testing at room temperature (25℃). The HER test voltage range of the working electrode was 0V to -0.8V (vsRHE), and the OER test voltage range of the working electrode was 0V to 1.0V (vsRHE).

[0020] Comparative Example 4 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0021] (1) Cut a 1cm*1cm, 1mm thick 46-mesh nickel mesh coated with Raney nickel as the working electrode and pre-treat the electrode with alkaline washing. (2) Preparation of electrolyte: Sodium molybdate and lithium hydroxide were added to 1 M KOH solution and stirred to dissolve them to obtain modified electrolyte; the concentration of sodium molybdate in the solution was 0.05 mol / L and the concentration of lithium hydroxide in the solution was 0.5 mol / L. (3) CV activation of the electrode: The 46-mesh nickel mesh electrode coated with Raney nickel was immersed in the modified electrolyte. The working electrode was the 46-mesh nickel mesh coated with Raney nickel, the counter electrode was a graphite rod, and the reference electrode was Hg / HgO. The electrode was subjected to CV activation treatment with an activation voltage range of -1.0V to 1.0V, a scanning rate of 0.001mV / s, and 10 scans to obtain the NiMo bimetallic catalyst. Subsequently, the electrode was subjected to LSV testing at room temperature (25℃). The HER test voltage range of the working electrode was 0V to -0.8V (vsRHE), and the OER test voltage range of the working electrode was 0V to 1.0V (vsRHE).

[0022] Comparative Example 5 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0023] (1) Cut a 1cm*1cm, 1mm thick 46-mesh nickel mesh coated with Raney nickel as the working electrode and pre-treat the electrode with alkaline washing. (2) Preparation of electrolyte: Ammonium molybdate and lithium hydroxide were added to 1 M KOH solution and stirred to dissolve them to obtain the modified electrolyte; the concentration of ammonium molybdate in the solution was 0.05 mol / L and the concentration of lithium hydroxide in the solution was 0.5 mol / L. (3) CV activation of the electrode: The 46-mesh nickel mesh electrode coated with Raney nickel was immersed in the modified electrolyte. The working electrode was the 46-mesh nickel mesh coated with Raney nickel, the counter electrode was a graphite rod, and the reference electrode was Hg / HgO. The electrode was subjected to CV activation treatment with an activation voltage range of -1.0V to 1.0V, a scanning rate of 0.001mV / s, and 10 scans to obtain the NiMo bimetallic catalyst. Subsequently, the electrode was subjected to LSV testing at room temperature (25℃). The HER test voltage range of the working electrode was 0V to -0.8V (vsRHE), and the OER test voltage range of the working electrode was 0V to 1.0V (vsRHE).

[0024] Comparative Example 6 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0025] (1) Cut a 1cm*1cm, 1mm thick 46-mesh nickel mesh coated with Raney nickel as the working electrode and pre-treat the electrode with alkaline washing. (2) Preparation of electrolyte: Zinc molybdate and lithium hydroxide were added to 1 M KOH solution and stirred to dissolve them to obtain modified electrolyte; the concentration of zinc molybdate in the solution was 0.05 mol / L and the concentration of lithium hydroxide in the solution was 0.5 mol / L. (3) CV activation of the electrode: The 46-mesh nickel mesh electrode coated with Raney nickel was immersed in the modified electrolyte. The working electrode was the 46-mesh nickel mesh coated with Raney nickel, the counter electrode was a graphite rod, and the reference electrode was Hg / HgO. The electrode was subjected to CV activation treatment with an activation voltage range of -1.0V to 1.0V, a scan rate of 0.001mV / s, and 10 scan cycles to obtain the NiMo bimetallic catalyst. Subsequently, the electrode was subjected to LSV testing at room temperature (25℃). The HER test voltage range of the working electrode was 0V to -0.8V (vsRHE), and the OER test voltage range of the working electrode was 0V to 1.0V (vsRHE).

[0026] Comparative Example 7 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0027] (1) Cut a 1cm*1cm, 1mm thick 46-mesh nickel mesh coated with Raney nickel as the working electrode and pre-treat the electrode with alkaline washing. (2) Preparation of electrolyte: Lithium hydroxide was added to 1 M KOH solution and stirred to dissolve it to obtain the modified electrolyte; the concentration of lithium hydroxide in the solution was 0.5 mol / L; (3) CV activation of the electrode: The 46-mesh nickel mesh electrode coated with Raney nickel was immersed in the modified electrolyte. The working electrode was a 46-mesh nickel mesh coated with Raney nickel, the counter electrode was a graphite rod, and the reference electrode was Hg / HgO. The electrode was subjected to CV activation treatment with an activation voltage range of -1.0V to 1.0V, a scanning rate of 0.001mV / s, and 10 scans. Subsequently, the electrode was subjected to LSV testing at room temperature (25℃). The HER test voltage range of the working electrode was 0V to -0.8V (vsRHE), and the OER test voltage range of the working electrode was 0V to 1.0V (vsRHE).

[0028] Comparative Example 8 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0029] (1) Cut a 1cm*1cm, 1mm thick 46-mesh nickel mesh coated with Raney nickel as the working electrode and pre-treat the electrode with alkaline washing. (2) Preparation of electrolyte: Potassium molybdate was added to 1 M KOH solution and stirred to dissolve it to obtain the modified electrolyte; the concentration of potassium molybdate in the solution was 0.05 mol / L; (3) CV activation of the electrode: The 46-mesh nickel mesh electrode coated with Raney nickel was immersed in the modified electrolyte. The working electrode was the 46-mesh nickel mesh coated with Raney nickel, the counter electrode was a graphite rod, and the reference electrode was Hg / HgO. The electrode was subjected to CV activation treatment with an activation voltage range of -1.0V to 1.0V, a scanning rate of 0.001mV / s, and 10 scans to obtain the NiMo bimetallic catalyst. Subsequently, the electrode was subjected to LSV testing at room temperature (25℃). The HER test voltage range of the working electrode was 0V to -0.8V (vsRHE), and the OER test voltage range of the working electrode was 0V to 1.0V (vsRHE).

[0030] Comparative Example 9 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0031] (1) Select a 46-mesh nickel mesh coated with Raney nickel as the working electrode and perform alkaline washing pretreatment on the electrode; (2) Preparation of electrolyte: Potassium molybdate and lithium hydroxide were added to 1 M KOH solution and stirred to dissolve them to obtain modified electrolyte; the concentration of potassium molybdate in the solution was 0.05 mol / L and the concentration of lithium hydroxide in the solution was 0.5 mol / L. (3) The 46-mesh nickel mesh electrodes coated with Raney nickel were used as the anode and cathode of the electrolytic cell, respectively, and assembled into the electrolytic cell. Then, the modified electrolyte was added to the alkaline tank of the electrolytic cell system, and a current density of 5000 A / m was applied. 2 The DC power supply is applied and the temperature begins to rise. This process causes the electrode to combine with metal ions in the metal to obtain a surface-loaded NiMo electrode.

[0032] Comparative Example 10 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0033] (1) Select a 46-mesh nickel mesh coated with Raney nickel as the working electrode and perform alkaline washing pretreatment on the electrode; (2) Preparation of electrolyte: Sodium molybdate and lithium hydroxide were added to a 30wt% KOH solution and stirred to dissolve them to obtain a modified electrolyte; the concentration of sodium molybdate in the solution was 0.05mol / L and the concentration of lithium hydroxide in the solution was 0.5mol / L. (3) The 46-mesh nickel mesh electrodes coated with Raney nickel were used as the anode and cathode of the electrolytic cell, respectively, and assembled into the electrolytic cell. Then, the modified electrolyte was added to the alkaline tank of the electrolytic cell system, and a current density of 5000 A / m was applied. 2The DC power supply is applied and the temperature begins to rise. This process causes the electrode to combine with metal ions in the metal to obtain a novel electrode with a surface loaded with NiMo, increased specific surface area, uniform distribution of active sites, and good catalytic activity in an alkaline environment.

[0034] Comparative Example 11 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0035] (1) Select a 46-mesh nickel mesh coated with Raney nickel as the working electrode and perform alkaline washing pretreatment on the electrode; (2) Preparation of electrolyte: Ammonium molybdate and lithium hydroxide were added to a 30wt% KOH solution and stirred to dissolve them to obtain the modified electrolyte; the concentration of ammonium molybdate in the solution was 0.05mol / L and the concentration of lithium hydroxide in the solution was 0.5mol / L. (3) The 46-mesh nickel mesh electrodes coated with Raney nickel were used as the anode and cathode of the electrolytic cell, respectively, and assembled into the electrolytic cell. Then, the modified electrolyte was added to the alkaline tank of the electrolytic cell system, and a current density of 5000 A / m was applied. 2 The DC power supply is applied and the temperature begins to rise. This process causes the electrode to combine with metal ions in the metal to obtain a surface-loaded NiMo electrode.

[0036] Comparative Example 12 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0037] (1) Select a 46-mesh nickel mesh coated with Raney nickel as the working electrode and perform alkaline washing pretreatment on the electrode; (2) Preparation of electrolyte: Zinc molybdate, sodium selenate and lithium hydroxide were added to a 30wt% KOH solution and stirred to dissolve to obtain a modified electrolyte; the concentration of zinc molybdate in the solution was 0.05mol / L and the concentration of lithium hydroxide in the solution was 0.5mol / L. (3) The 46-mesh nickel mesh electrodes coated with Raney nickel were used as the anode and cathode of the electrolytic cell, respectively, and assembled into the electrolytic cell. Then, the modified electrolyte was added to the alkaline tank of the electrolytic cell system, and a current density of 5000 A / m was applied. 2 The DC power supply is applied and the temperature begins to rise. This process causes the electrode to combine with metal ions in the metal to obtain a surface-loaded NiMo electrode.

[0038] Comparative Example 13 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0039] (1) Select a 46-mesh nickel mesh coated with Raney nickel as the working electrode and perform alkaline washing pretreatment on the electrode; (2) Preparation of electrolyte: Lithium hydroxide was added to a 30wt% KOH solution and stirred to dissolve it to obtain the modified electrolyte; the concentration of lithium hydroxide in the solution was 0.5mol / L; (3) The 46-mesh nickel mesh electrodes coated with Raney nickel were used as the anode and cathode of the electrolytic cell, respectively, and assembled into the electrolytic cell. Then, the modified electrolyte was added to the alkaline tank of the electrolytic cell system, and a current density of 5000 A / m was applied. 2 DC power supply.

[0040] Comparative Example 14 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0041] (1) Select a 46-mesh nickel mesh coated with Raney nickel as the working electrode and perform alkaline washing pretreatment on the electrode; (2) Preparation of electrolyte: Potassium molybdate was added to a 30wt% KOH solution and stirred to dissolve it to obtain the modified electrolyte; the concentration of potassium molybdate in the solution was 0.05mol / L. (3) The 46-mesh nickel mesh electrodes coated with Raney nickel were used as the anode and cathode of the electrolytic cell, respectively, and assembled into the electrolytic cell. Then, the modified electrolyte was added to the alkaline tank of the electrolytic cell system, and a current density of 5000 A / m was applied. 2 The DC power supply is applied and the temperature begins to rise. This process causes the electrode to combine with metal ions in the metal to obtain a surface-loaded NiMo electrode.

[0042] Example 1 The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0043] (1) Cut a 1cm*1cm, 1mm thick 46-mesh nickel mesh coated with Raney nickel as the working electrode and pre-treat the electrode with alkaline washing. (2) Preparation of electrolyte: Potassium molybdate, sodium selenate and lithium hydroxide were added to 1 M KOH solution and stirred to dissolve to obtain modified electrolyte; the concentration of potassium molybdate in the solution was 0.05 mol / L, the concentration of lithium hydroxide in the solution was 0.5 mol / L, and the concentration of sodium selenate in the solution was 0.05 mol / L. (3) CV activation of the electrode: The 46-mesh nickel mesh electrode coated with Raney nickel was immersed in the modified electrolyte. The working electrode was the 46-mesh nickel mesh coated with Raney nickel, the counter electrode was a graphite rod, and the reference electrode was Hg / HgO. The electrode was subjected to CV activation treatment. The activation voltage range was -1.0V to 1.0V, the scanning rate was 0.001mV / s, and the number of scans was 10. The doping of Mo element did react with the nickel mesh to produce new substances and reconstruct the surface morphology of the nickel mesh, thus obtaining the NiMo bimetallic catalyst. Subsequently, the electrode was subjected to LSV test at room temperature (25℃). The HER test voltage range of the working electrode was 0V to -0.8V (vsRHE), and the OER test voltage range of the working electrode was 0V to 1.0V (vsRHE). Example 2

[0044] The modified electrolyte preparation method of this application was used as the electrolyte for electrolytic cell testing.

[0045] (1) Select a 46-mesh nickel mesh coated with Raney nickel as the working electrode and perform alkaline washing pretreatment on the electrode; (2) Preparation of electrolyte: Potassium molybdate, sodium selenate and lithium hydroxide were added to a 30wt% KOH solution and stirred to dissolve to obtain a modified electrolyte; the concentration of potassium molybdate in the solution was 0.05mol / L, the concentration of lithium hydroxide in the solution was 0.5mol / L, and the concentration of sodium selenate in the solution was 0.05mol / L. (3) The 46-mesh nickel mesh electrodes coated with Raney nickel were used as the anode and cathode of the electrolytic cell, respectively, and assembled into the electrolytic cell. Then, the modified electrolyte was added to the alkaline tank of the electrolytic cell system, and a current density of 5000 A / m was applied. 2 The DC power supply is applied and the temperature begins to rise. This process causes the electrode to combine with metal ions in the metal to obtain a novel electrode with surface-loaded NiMo and NiMoSe, increased specific surface area, uniform distribution of active sites, and good catalytic activity in an alkaline environment.

[0046] Effect Experiment The hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance of the blank control electrolyte (1M potassium hydroxide aqueous solution) in the comparative example and the modified electrolytes in Examples 1 and 2 were tested. The specific tests are as follows: In the standard three-electrode system, the working electrode is a 46-mesh nickel mesh coated with Raney nickel, the counter electrode is a graphite rod, and the reference electrode is Hg / HgO.

[0047] Electrode activation (CV): Before performing LSV testing on the electrode, the electrode is first activated by CV. The activation voltage range is -1.0V to 1.0V, the scanning rate is 0.001mV / s, and the number of scans is 10.

[0048] Detection method (LSV): The 1M potassium hydroxide aqueous solution from Comparative Example 1 and the modified electrolytes from Examples 1-6 were respectively poured into an electrolytic cell for linear sweep voltammetry (LSV) testing. The electrolyte testing temperature was room temperature (25°C), the HER testing voltage range of the working electrode was 0V to -0.8V (vsRHE), and the OER testing voltage range of the working electrode was 0V to 1.0V (vsRHE).

[0049] The test results are shown in Table 1 below, corresponding to the overpotential test results. Table 1

[0050]

[0051] As can be seen from the comparison in Table 1, the modified electrolyte in Example 1 has significantly reduced hydrogen evolution and oxygen evolution overpotentials compared to Comparative Examples 1, 3-8. Specifically, the hydrogen evolution overpotential is reduced by 78 mV and the oxygen evolution overpotential is reduced by 125 mV compared to Comparative Example 1.

[0052] The test results are shown in Table 2 below, corresponding to the electrolytic cell test results.

[0053] Table 2

[0054] The electrodes of Comparative Example 2, the blank control electrolyte (30 wt% potassium hydroxide aqueous solution) and the modified electrolyte of Example 2 were tested using a 10-square-meter electrolytic cell with a papillary structure.

[0055] Testing method: A 46-mesh Raney nickel mesh was used as the electrode. The electrolyte temperature was controlled at 85℃ during operation, and electrolysis was performed in cross-flow mode. The current density was set to 4000 A / m², and the continuous electrolysis time was 10 hours. During electrolysis, the system recorded the voltage of the electrolytic cell every hour.

[0056] According to Table 2 above, the comparison shows that the modified electrolyte with added additives resulted in a lower average voltage in the electrolyzer compared to Comparative Example 2. In particular, in Example 2, compared to the blank control electrolyte (30 wt% potassium hydroxide aqueous solution) in Comparative Example 2, the average voltage reduction in the electrolyzer in Example 14 was 0.232 V, effectively reducing electrolysis energy consumption.

[0057] Performance tests were conducted using a 10-square-meter electrolytic cell with a papillary structure, combining hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance tests. It can be seen that during electrolysis, the modified electrolyte of this application significantly reduces the cell voltage, indicating that the modified electrolyte has a significant reduction effect on both the cathode HER overpotential and the anodic OER overpotential. The introduction of metal ions from molybdate and sodium selenate into the electrolyte allows for the activation process before testing, during which Mo and Se combine with the Ni electrode to form NiMo and NiMoSe metal compounds on the electrode surface. This alters the electrode's material composition and surface morphology, exposing more active sites and improving the electrode's electrolysis efficiency. This results in a significant reduction in both the cathode HER and anodic OER overpotential. Furthermore, the addition of lithium hydroxide increases the ion concentration in the electrolyte, promoting water dissociation. This is because Li... + The mobility is higher than K + The addition of Se helps to improve the conductivity of the electrolyte, further reduce electrolysis energy consumption, and further lower the electrolytic cell voltage. In addition, the addition of Se facilitates the timely desorption of bubbles, including smaller ones, from the electrode surface, thereby ensuring sufficient contact between the electrolyte and the catalyst, reducing diffusion limitations caused by bubbles, improving electrolysis efficiency, and lowering the electrolysis voltage. The results show that the addition of molybdate, sodium selenate, and lithium hydroxide collectively promotes the reduction of electrolysis reaction energy consumption.

[0058] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A modified electrolyte for alkaline water electrolysis, characterized in that, include: An alkaline electrolyte solution, molybdic acid or molybdate, sodium selenate, and lithium hydroxide added to the alkaline electrolyte solution, are used to generate a modified electrolyte solution by adding molybdic acid or molybdate, sodium selenate, and lithium hydroxide to the alkaline electrolyte solution and stirring to dissolve them. The concentration of molybdate in the modified electrolyte solution is 0.01 mol / L to 1 mol / L, the concentration of sodium selenate additive is 0.0005 mol / L to 0.1 mol / L, and the concentration of lithium hydroxide additive in the electrolyte solution is 0.01 mol / L to 1 mol / L.

2. The modified electrolyte for alkaline water electrolysis according to claim 1, characterized in that, The alkaline electrolyte solution is a potassium hydroxide solution or a sodium hydroxide solution.

3. The modified electrolyte for alkaline water electrolysis according to claim 1, characterized in that, The alkaline electrolyte solution contains 15 wt% to 45 wt% potassium hydroxide or sodium hydroxide.

4. The modified electrolyte for alkaline water electrolysis according to claim 1, characterized in that, The molybdate additive is one of potassium molybdate, sodium molybdate, calcium molybdate, ammonium molybdate, ammonium heptamolybdate, calcium molybdate, barium molybdate, lead molybdate, zinc molybdate, lanthanum molybdate, and yttrium molybdate.

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