Electrolyte for electrocatalytic reduction of carbon monoxide from carbon dioxide as well as preparation method and application of electrolyte
By using specific ionic liquids and auxiliary agents in the electrolyte for electrocatalytic reduction of carbon monoxide, the problems of high viscosity and low stability of the electrolyte are solved, and catalytic conversion efficiency and environmental protection are improved.
Patent Information
- Application Number
- CN202510042162.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-10
- Publication Date
- 2025-05-02
AI Technical Summary
The existing electrolyte for electrocatalyzed carbon dioxide carbon monoxide has problems of excessive viscosity and low stability, resulting in low catalytic conversion efficiency.
An ionic liquid including 1-ethyl-3-methylimidazole bistrifluoromethanesulfonimide salt solution and 1-hexyl-3-methylimidazole hexafluorophosphate solution was prepared by combining organic additives, phase transfer catalysts, conductive agents and pH regulators.
It improves the solubility of carbon dioxide and the efficiency of electrocatalytic reactions, enhances the rate and yield of the reaction, and improves the thermal stability and environmental protection of the electrolyte and reduces pollution.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of electrocatalysis technology, and in particular to an electrolyte for electrocatalytic reduction of carbon monoxide by carbon dioxide, a preparation method and an application thereof. Background Art
[0002] Since the Industrial Revolution, the extensive use of fossil fuels has caused a sharp increase in the concentration of carbon dioxide in the atmosphere. The global concentration of carbon dioxide in the atmosphere has risen to a relatively high level in recent years, triggering a series of environmental problems such as global warming and ocean acidification. Therefore, how to reduce carbon dioxide emissions and effectively convert and utilize them has become an important task that humans need to solve urgently. At present, when electrocatalyzing the reduction of carbon monoxide by carbon dioxide, the main problems faced are the difficulty in selecting catalysts, low conversion efficiency of the reaction, high energy consumption, unstable energy sources, and the impact of post-reaction emissions on the environment. Regarding the selection of electrolytes, it is often necessary to consider the cost of raw materials, the synthesis process, the viscosity of the electrolyte, the electrochemical properties, the actual compatibility, stability and other issues.
[0003] In view of this, the present invention provides an electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide, as well as a preparation method and application thereof, so as to solve the many problems encountered by the above-mentioned technologies and achieve sustainable development. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide an electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide, a preparation method and an application thereof. The purpose is to avoid the problem of excessively high viscosity and low stability of the electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide, thereby improving the catalytic conversion efficiency.
[0005] The technical solution of the present invention to solve the above technical problems is as follows:
[0006] In a first aspect, an electrolyte for the electrocatalytic reduction of carbon monoxide with carbon dioxide comprises the following raw materials in parts by weight: 4 to 6 parts of 1-ethyl-3-methylimidazole bistrifluoromethanesulfonyl imide salt solution, 1 to 4 parts of 1-hexyl-3-methylimidazole hexafluorophosphate solution, 0.25 to 1.5 parts of an organic additive, 0.1 to 0.6 parts of a phase transfer catalyst, 0.1 to 0.3 parts of a conductive agent, and 0.05 to 0.15 parts of a pH adjusting agent; the pH value of the electrolyte is 4.5 to 5.5.
[0007] The beneficial effects of the present invention are as follows: (1) the ionic liquid composed of 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt solution and 1-hexyl-3-methylimidazolium hexafluorophosphate salt solution has good solubility, can further increase the solubility of carbon dioxide, and promote the progress of the electrocatalytic reaction; and it has good dispersion performance and can fully contact the surface of the phase transfer catalyst to improve the reaction rate and efficiency, and further improve the yield of carbon monoxide;
[0008] (2) Since increasing the solubility of carbon dioxide requires creating a high temperature and low pressure environment, the electrolyte of the present invention can still remain in liquid form at a relatively high temperature and has good thermal stability, which also ensures that the reaction system operates stably within a certain temperature range and will not decompose or deteriorate due to temperature increases;
[0009] (3) The raw materials of the electrolyte of the present invention are more environmentally friendly and can further reduce pollution during production and discharge.
[0010] Based on the above technical solution, the present invention can also be improved as follows.
[0011] Furthermore, the organic auxiliary agent includes dimethylformamide; the phase transfer catalyst includes benzyltriethylammonium chloride; the conductive agent includes superconducting carbon black; and the pH adjusting agent includes polymaleic acid.
[0012] The beneficial effects of adopting the above further scheme are: the organic auxiliary agent with polarity can fully dissolve the 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution and the 1-hexyl-3-methylimidazolium hexafluorophosphate solution and mix them evenly, and can also adjust the rate in the subsequent reaction and increase the collision frequency between the reactants. At the same time, its chemical properties are relatively stable and will not interfere with the progress of the subsequent electrocatalytic reaction; the use of a phase transfer catalyst can promote the reaction between the organic phase and the aqueous phase, so that some cations can form ion pairs with the anionic reactants, thereby transferring the anions from the aqueous phase to the organic phase, accelerating the reaction, which can improve the reaction rate of the reactants. Selectivity, in order to reduce the occurrence of side reactions and improve the purity of the product; since the viscosity of ionic liquids is often high, it will hinder the rapid migration of ions therein, resulting in a decrease in conductivity, and the use of conductive agents can effectively increase the conductivity of ionic liquids, which helps to promote the process of electrocatalytic reduction of carbon monoxide by carbon dioxide; the use of pH adjusting agents is intended to provide more stable conditions for the entire electrolyte environment in a weakly acidic environment of pH 4.5 to 5.5, prevent decomposition or deterioration, etc., which is beneficial to the subsequent electrocatalytic reaction, and at the same time can inhibit the formation of carbonic acid in the process of electrocatalytic reduction of carbon monoxide by carbon dioxide, thereby improving the reaction efficiency.
[0013] Furthermore, the particle size of the superconducting carbon black is 0.5 mm to 2.5 mm.
[0014] The beneficial effect of adopting the above further scheme is that the use of superconducting carbon black with a particle size of 0.5 mm to 2.5 mm can effectively increase the conductivity of the ionic liquid, which helps to promote the process of electrocatalytic reduction of carbon monoxide by carbon dioxide.
[0015] Furthermore, the water content of the 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt solution is less than 1000 ppm, and the purity is ≥99%; the water content of the 1-hexyl-3-methylimidazolium hexafluorophosphate solution is less than 1000 ppm, and the purity is ≥98%.
[0016] The beneficial effect of adopting the above further scheme is that the electrolyte prepared according to the above components, water content and purity can significantly improve the efficiency of electrocatalytic reduction of carbon monoxide by carbon dioxide.
[0017] In a second aspect, a method for preparing an electrolyte for electrocatalytic reduction of carbon monoxide by carbon dioxide comprises the following steps:
[0018] (1) adding a 1-hexyl-3-methylimidazolium hexafluorophosphate solution to a 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt solution to obtain a mixed solution; adding an organic auxiliary agent to the mixed solution, and heating the mixed solution at a first temperature (e.g., a salt bath) to obtain a first sol-like ion mixed solution;
[0019] (2) adding a phase transfer catalyst to the first sol-like ion mixed solution under reflux condensation at a second temperature, wherein the second temperature is higher than the first temperature, to obtain a second sol-like ion mixed solution;
[0020] (3) adding a conductive agent to the second sol-like ion mixed solution, and mixing the mixture uniformly at a constant temperature under a vacuum state to obtain a third sol-like ion mixed solution; and adjusting the pH value of the third sol-like ion mixed solution to obtain an electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide.
[0021] The beneficial effect of adopting the above scheme is that the electrolyte prepared by the above steps not only solves the problems encountered by the current electrolyte, such as high viscosity and poor conductivity, unstable liquid system, and a large number of by-products, but also further improves the efficiency of electrocatalytic reduction of carbon monoxide by carbon dioxide.
[0022] Furthermore, the parameters for heating at the first temperature in step (1) are: 80° C. to 100° C., 6 h to 8 h;
[0023] Furthermore, the mass ratio of the organic auxiliary agent to the mixed solution is 1-3:20; the mass ratio of the 1-ethyl-3-methylimidazole bistrifluoromethanesulfonyl imide salt solution to the 1-hexyl-3-methylimidazole hexafluorophosphate solution is 4-6:1-4.
[0024] The beneficial effects of adopting the above further scheme are: the main purpose of adopting the above heating parameters is to provide a higher temperature, which helps to fully stir the mixed liquid and increase the contact time between the two, while preventing the agglomeration of ions; the stirring time of 6 to 8 hours is to ensure that the reaction is fully carried out; the heating temperature of 80 to 100°C is to provide sufficient energy for the reaction and accelerate the reaction rate.
[0025] Furthermore, the second temperature and reflux condensation parameters in step (2) are: 350°C to 380°C, the reflux rate is controlled at 1 to 3 drops / second, and the reflux time is 8h to 12h;
[0026] Furthermore, the mass ratio of the phase transfer catalyst to the first sol-like ion mixed solution is 2 to 6:100.
[0027] The beneficial effect of adopting the above further scheme is: the main purpose of adopting the above parameters is that the temperature of 350-380°C can give the reactants enough energy to overcome the activation energy barrier of the reaction, thereby improving the conversion rate of the reaction, and making the sol-like ion mixed solution reach the boiling point, which is conducive to subsequent condensation reflux, and also helps the phase transfer catalyst to be evenly distributed in the reaction system, thereby improving the efficiency of the electrolyte in the subsequent reaction;
[0028] The reflux condensation can use a serpentine condenser, the purpose of which is to provide a larger condensation area, good heat exchange efficiency, and suitable for refluxing high-temperature liquids. The slow reflux rate and longer reflux time help to improve the purity of the reactants.
[0029] Furthermore, the parameters of the constant temperature mixing in step (3) are: a rotation speed of 300 rpm to 350 rpm and a temperature of 200° C. to 220° C.;
[0030] Furthermore, the mass ratio of the conductive agent to the second sol-like ion mixed solution is 2 to 3:100.
[0031] The beneficial effect of adopting the above further scheme is: the purpose of adopting the above rotation speed of 300-350rpm and temperature of 200-220℃ is to increase the collision frequency between ions and accelerate the reaction rate by accurately controlling the rotation speed and temperature, and at the same time improve the uniformity of the reaction and promote heat transfer.
[0032] Furthermore, the pH of the electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide is between 4.5 and 5.5.
[0033] The beneficial effect of adopting the above further scheme is that in a weakly acidic environment with a pH of 4.5 to 5.5, a more stable condition can be provided for the entire electrolyte environment, preventing decomposition or deterioration, which is beneficial to the subsequent electrocatalytic reaction. At the same time, it can inhibit the formation of carbonic acid during the electrocatalytic reduction of carbon monoxide by carbon dioxide, thereby improving the reaction efficiency.
[0034] In a third aspect, an application of an electrolyte for the electrocatalytic reduction of carbon dioxide to carbon monoxide is to use the electrolyte for the electrocatalytic reduction of carbon dioxide to carbon monoxide. DETAILED DESCRIPTION
[0035] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.
[0036] Example 1
[0037] (1) adding 2.6 parts by weight of 1-hexyl-3-methylimidazolium hexafluorophosphate solution (McLean's reagent) (water content <1000 ppm, purity ≥98%) to 5.2 parts by weight of 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt solution (McLean's reagent) (water content <1000 ppm, purity ≥99%) to obtain a mixed solution; adding an organic auxiliary agent dimethylformamide to the mixed solution, the mass ratio of the dimethylformamide to the mixed solution being 1.5:20, and heating in a salt bath for 6 hours at a temperature of 70° C. to obtain a first sol-like ion mixed solution;
[0038] (2) continuing to raise the temperature of the first sol-like ion mixed solution to 350° C., adding a phase transfer catalyst benzyltriethylammonium chloride (McLean reagent) dropwise, wherein the mass ratio of the benzyltriethylammonium chloride to the first sol-like ion mixed solution is 3:100, and connecting a reflux device equipped with a serpentine condenser, wherein the reflux rate is controlled at 1 to 3 drops / second, and the reflux time is 8 to 12 hours, to obtain a second sol-like ion mixed solution;
[0039] (3) pouring the second sol-like ion mixed solution into a reactor, and adding a conductive agent superconducting carbon black (particle size of 0.8 mm) (Tianjin Huacai Chemical Co., Ltd.), the mass ratio of the superconducting carbon black to the second sol-like ion mixed solution is 2.5:100, evacuating the reactor, placing it in a homogeneous reactor for constant temperature rotation stirring at a speed of 350 rpm and a temperature of 200° C., to obtain a third sol-like ion mixed solution;
[0040] (4) The third sol-like ion mixed solution is cooled to 25° C., and the pH value is adjusted to 4.5 to 5.5 by dropping polymaleic acid (McLean's reagent) to obtain the electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide.
[0041] Embodiment 2-3:
[0042] Example 2-3 is the same as Example 1, the only difference being the addition amount of 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt solution and 1-hexyl-3-methylimidazolium hexafluorophosphate solution. The other raw materials and steps are the same as those in Example 1. The addition amount of carbon material in Example 2-3 is shown in Table 1:
[0043] Table 1
[0044]
[0045] Comparative Example 1:
[0046] The difference between this comparative example and Example 1 is that the phase transfer catalyst benzyltriethylammonium chloride is not added in step (2), and the other raw materials and steps are the same as those in Example 1. Step (2) is as follows:
[0047] (2) Continue to raise the temperature of the first sol-like ion mixed solution to 350° C. and connect a reflux device equipped with a serpentine condenser. The reflux rate is controlled at 1 to 3 drops per second and the reflux time is 8 to 12 hours.
[0048] Comparative Example 2:
[0049] The difference between this comparative example and Example 1 is that the temperature of the homogeneous reactor in step (3) does not reach the specified range, and the other raw materials and steps are the same as those in Example 1. Step (3) is as follows:
[0050] (3) Pour the second sol-like ion mixed solution into a reactor, and add a conductive agent superconducting carbon black (particle size of 0.8 mm), the mass ratio of the superconducting carbon black to the second sol-like ion mixed solution is 2.5:100, evacuate the reactor, put it into a homogeneous reactor for constant temperature rotation stirring, the rotation speed is 350 rpm, and the temperature is 100°C.
[0051] Comparative Example 3:
[0052] The difference between this comparative example and Example 1 is that the conductive agent superconducting carbon black is not added in step (3), and the other raw materials and steps are the same as those in Example 1. Step (3) is as follows:
[0053] (3) Pour the second sol-like ion mixed solution into a reaction kettle and evacuate it, then place it into a homogeneous reactor for constant temperature rotation stirring at a speed of 350 rpm and a temperature of 200°C.
[0054] Comparative Example 4:
[0055] The difference between this comparative example and Example 1 is that the condensation reflux operation is not performed in step (2), and the other raw materials and steps are the same as those in Example 1. Step (1) is as follows:
[0056] (2) The temperature of the second sol-like ion mixed solution is continued to be raised to 350° C., and a phase transfer catalyst, benzyltriethylammonium chloride, is added dropwise in a mass ratio of 3:100 to the sol-like ion mixed solution.
[0057] Comparative Example 5:
[0058] The difference between this comparative example and Example 1 is that the 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt solution is not added in step (1), and the remaining raw materials and steps are the same as those in Example 1. Step (1) is as follows:
[0059] (1) adding an organic auxiliary agent dimethylformamide to 2.6 parts by weight of a 1-hexyl-3-methylimidazolium hexafluorophosphate solution, wherein the mass ratio of dimethylformamide to the above solution is 1.5:20, and heating is performed in a salt bath for 6 hours at a temperature of 70° C. to obtain a first sol-like ion mixed solution;
[0060] Comparative Example 6:
[0061] The difference between this comparative example and Example 1 is that the 1-hexyl-3-methylimidazolium hexafluorophosphate solution is not added in step (1), and the other raw materials and steps are the same as those in Example 1. Step (1) is as follows:
[0062] (1) adding an organic auxiliary agent dimethylformamide to 5.2 parts by weight of a 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution, wherein the mass ratio of dimethylformamide to the above solution is 1.5:20, and heating is performed in a salt bath for 6 hours at a temperature of 70° C. to obtain a first sol-like ion mixed solution;
[0063] Test example:
[0064] An electrocatalytic reactor is set up, wherein the electrodes are platinum electrodes and zinc electrodes, and the electrolyte solution is the electrolyte for electrocatalytic reduction of carbon monoxide by carbon dioxide of the present invention. The test steps are as follows:
[0065] (1) The electrolyte (Examples 1-3 and Comparative Examples 1-6) is added to the reactor and the electrodes are connected; carbon dioxide is transported to the cathode chamber through a supply device and adsorbed on the surface of the zinc electrode, thereby starting the electrocatalytic reactor to initiate the reaction.
[0066] (2) The mixed gas produced by the electrocatalytic reaction in the same period of time was collected by gas phase method, and the conversion rate of carbon monoxide was analyzed and calculated by gas chromatography. The results are shown in Table 2.
[0067] Table 2
[0068]
[0069] From Table 2, we can see that:
[0070] (1) The electrolytic solutions for the electrocatalytic reduction of carbon monoxide by carbon dioxide prepared in Examples 1-3 all maintained a conversion rate of carbon monoxide product above 91%. Comparison of Comparative Example 1 with Example 1 shows that in the process of preparing the electrolytic solution for the electrocatalytic reduction of carbon monoxide by carbon dioxide, the phase transfer catalyst benzyltriethylammonium chloride is not added, resulting in the failure of the activated carbon dioxide intermediate to form ion pairs and intermediate products in time during the electronic coupling reaction process, thereby delaying the progress of the reaction.
[0071] (2) By comparing Comparative Example 2 with Examples 1-3 of the present invention, it can be seen that if the temperature of the homogeneous reactor is greatly reduced to prepare an electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide, the activity of the ionic components of the electrolyte is not fully stimulated due to failure to reach the appropriate temperature. As a result, during the electrocatalytic reaction, the contact frequency between carbon dioxide and the ions in the electrolyte is reduced, and carbon monoxide cannot be generated quickly.
[0072] (3) Compared with the above-mentioned Example 1, it can be seen that in Example 3, the conductive agent superconducting carbon black is not added to prepare the electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide. Since the conductive agent superconducting carbon black is not added, the conductivity of the electrolyte is slightly low, making the carbon monoxide conversion rate lower than that of Examples 1-3.
[0073] (4) In Comparative Example 4, the condensation reflux operation was not performed in the electrolyte prepared for the electrocatalytic reduction of carbon monoxide by carbon dioxide, resulting in that some impurities contained in the electrolyte were not separated, affecting the efficiency of the subsequent electrocatalytic reduction of carbon monoxide by carbon dioxide.
[0074] (5) In Comparative Example 5, no ionic liquid: 1-ethyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt solution was added to the electrolyte for preparing the electrocatalytic reduction of carbon monoxide by carbon dioxide, so that the introduced carbon dioxide could not be completely dissolved in the electrolyte for reaction and was subsequently collected together with the product carbon monoxide, thereby reducing the conversion rate of carbon monoxide.
[0075] (6) In Comparative Example 6, no ionic liquid was added to the electrolyte for preparing the electrocatalytic reduction of carbon monoxide by carbon dioxide: 1-hexyl-3-methylimidazolium hexafluorophosphate solution. The lack of its good dispersion properties prevented the various components from fully contacting each other, affecting the reaction rate and efficiency.
[0076] In summary, the electrolyte prepared by the above steps in the present invention not only solves the problems encountered by the current electrolyte, such as high viscosity and poor conductivity, unstable liquid system, and a large number of by-products, but also further improves the efficiency of electrocatalytic reduction of carbon monoxide by carbon dioxide, and reduces the pollution generated in subsequent emissions to achieve sustainable development.
[0077] Among them, polar dimethylformamide is used as an organic auxiliary agent to fully dissolve 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt solution and 1-hexyl-3-methylimidazolium hexafluorophosphate solution, and mix them evenly, and can also adjust the rate in the subsequent reaction and increase the collision frequency between the reactants. At the same time, its chemical properties are relatively stable and will not interfere with the progress of the subsequent electrocatalytic reaction; using benzyltriethylammonium chloride as a phase transfer catalyst can promote the reaction between the organic phase and the aqueous phase, so that some cations can form ion pairs with anionic reactants, thereby transferring anions from the aqueous phase to the organic phase, accelerating the reaction, and improving the selectivity of the reactants to reduce side reactions. The occurrence of electrocatalytic reduction of carbon monoxide by carbon dioxide can be improved, thereby improving the purity of the product; since the viscosity of ionic liquids is often high, it will hinder the rapid migration of ions therein, resulting in a decrease in electrical conductivity. The use of superconducting carbon black with a particle size of 0.5 to 2.5 mm as a conductive agent can effectively increase the electrical conductivity of the ionic liquid, which is helpful to promote the process of electrocatalytic reduction of carbon monoxide by carbon dioxide; the use of polymaleic acid as a pH regulator is intended to provide more stable conditions for the entire electrolyte environment in a weakly acidic environment of pH 4.5 to 5.5, prevent decomposition or deterioration, and is beneficial to the subsequent electrocatalytic reaction. At the same time, it can inhibit the formation of carbonic acid in the process of electrocatalytic reduction of carbon monoxide by carbon dioxide and improve the reaction efficiency.
[0078] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.
Claims
1. An electrolyte for electrocatalytic reduction of carbon monoxide by carbon dioxide, characterized in that: The electrolyte comprises the following raw materials in parts by weight: 4 to 6 parts of 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt solution, 1 to 4 parts of 1-hexyl-3-methylimidazolium hexafluorophosphate solution, 0.25 to 1.5 parts of organic additives, 0.1 to 0.6 parts of phase transfer catalysts, 0.1 to 0.3 parts of conductive agents, and 0.05 to 0.15 parts of pH adjusting agents; the pH value of the electrolyte is 4.5 to 5.
5.
2. The electrolyte for electrocatalytic reduction of carbon monoxide by carbon dioxide according to claim 1, characterized in that: The organic auxiliary agent includes dimethylformamide; the phase transfer catalyst includes benzyltriethylammonium chloride; the conductive agent includes superconducting carbon black; and the pH adjusting agent includes polymaleic acid.
3. The electrolyte for electrocatalytic reduction of carbon monoxide by carbon dioxide according to claim 2, characterized in that: The particle size of the superconducting carbon black is 0.5 mm to 2.5 mm.
4. The electrolyte for electrocatalytic reduction of carbon monoxide by carbon dioxide according to claim 1, characterized in that: The water content of the 1-ethyl-3-methylimidazolium bistrifluoromethanesulfonyl imide salt solution is less than 1000ppm, and the purity is ≥99%; the water content of the 1-hexyl-3-methylimidazolium hexafluorophosphate solution is less than 1000ppm, and the purity is ≥98%.
5. A method for preparing an electrolyte for electrocatalytic reduction of carbon monoxide by carbon dioxide according to any one of claims 1 to 4, characterized in that: The steps include: (1) adding a 1-hexyl-3-methylimidazolium hexafluorophosphate solution to a 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt solution to obtain a mixed solution; adding an organic auxiliary agent to the mixed solution, and heating at a first temperature to obtain a first sol-like ion mixed solution; (2) adding a phase transfer catalyst to the first sol-like ion mixed solution under reflux condensation at a second temperature, wherein the second temperature is higher than the first temperature, to obtain a second sol-like ion mixed solution; (3) adding a conductive agent to the second sol-like ion mixed solution, and mixing the mixture uniformly at a constant temperature under a vacuum state to obtain a third sol-like ion mixed solution; and adjusting the pH value of the third sol-like ion mixed solution to obtain an electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide.
6. The method for preparing an electrolyte for electrocatalytic reduction of carbon monoxide with carbon dioxide according to claim 5, characterized in that: The parameters for heating at the first temperature in step (1) are: 80° C. to 100° C., 6 h to 8 h.
7. The method for preparing an electrolyte for electrocatalytic reduction of carbon monoxide with carbon dioxide according to claim 5, characterized in that: The second temperature and reflux condensation parameters in step (2) are: 350°C to 380°C, the reflux rate is controlled at 1 to 3 drops / second, and the reflux time is 8h to 12h.
8. The method for preparing an electrolyte for electrocatalytic reduction of carbon monoxide with carbon dioxide according to claim 5, characterized in that: The parameters of the constant temperature mixing in step (3) are: a rotation speed of 300 rpm to 350 rpm and a temperature of 200° C. to 220° C.
9. The method for preparing an electrolyte for electrocatalytic reduction of carbon monoxide by carbon dioxide according to claim 5, characterized in that: The pH of the electrolyte for the electrocatalytic reduction of carbon monoxide by carbon dioxide is between 4.5 and 5.
5.
10. Application of an electrolyte for electrocatalytic reduction of carbon monoxide with carbon dioxide, characterized in that: The electrolyte for electrocatalytic reduction of carbon monoxide with carbon dioxide according to any one of claims 1 to 4 is used for electrocatalytic reduction of carbon monoxide with carbon dioxide.