Continuous and stable operation device and method for preparing formic acid by reducing carbon dioxide through electro-catalysis

Abstract

The invention belongs to the technical field of preparation of formic acid through electro-catalysis carbon dioxide reduction, and relates to a continuous and stable operation device and method for preparing formic acid through electro-catalysis carbon dioxide reduction. Comprising a gas cylinder, an electrolytic reactor system, an anolyte tank, an activating fluid tank and a product tank, the electrolytic reactor system comprises a plurality of reaction galvanic piles which are connected in parallel; a plurality of reaction stack cathode inlets are connected with a gas cylinder outlet; the anode inlets of the plurality of reaction galvanic piles are connected with the outlet of the anolyte tank and the outlet of the activating solution tank; the first outlets of the plurality of reaction galvanic piles are connected with the gas-liquid separation tank; and the second outlets of the plurality of reaction electric piles are connected with the inlet of the activation liquid tank and the product tank. According to the method, efficient and stable operation of preparing formic acid through reduction of carbon dioxide under electro-catalysis and flexible regulation and control of productivity are achieved, and a reliable technical scheme is provided for industrial application of preparing formic acid through reduction of carbon dioxide under electro-catalysis.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrocatalytic carbon dioxide reduction to prepare formic acid, and relates to a device and a method for continuously and stably operating electrocatalytic carbon dioxide reduction to prepare formic acid. BACKGROUND

[0002] With the continuous increase of global carbon emissions, carbon dioxide (CO2) emission reduction and resource utilization have become a research hotspot. The electrocatalytic carbon dioxide reduction technology (CO2RR) can convert CO2 into high-value-added chemicals such as formic acid (HCOOH), carbon monoxide (CO), and methane (CH4), which is one of the important ways to realize carbon recycling. Among them, formic acid, as an important chemical raw material and potential hydrogen energy carrier, has a wide application prospect in the fields of energy and chemical industry.

[0003] At present, the research on electrocatalytic CO2 reduction to prepare formic acid mainly focuses on catalyst design, reaction mechanism exploration, and electrolytic cell structure optimization. Although laboratory-scale research has made some progress, there are still many challenges in industrial application: first, the reaction system is difficult to achieve continuous and stable operation, and the catalyst is prone to activity attenuation due to local pH change, impurity adsorption or electrode structure damage under long-term working conditions; second, the cross mixing of cathode product formic acid and anode byproduct (such as oxygen) in the electrolyte not only reduces the purity of the product, but also may cause secondary oxidation reaction; in addition, the existing device lacks effective production capacity regulation mechanism, and it is difficult to adapt to the demand for flexible adjustment of production load in industrial scenarios. SUMMARY

[0004] To solve the problems in the prior art, the application provides a device and a method for continuously and stably operating electrocatalytic carbon dioxide reduction to prepare formic acid, which realizes efficient and stable operation of electrocatalytic carbon dioxide reduction to prepare formic acid and flexible regulation of production capacity, and provides a reliable technical solution for industrial application of electrocatalytic CO2 reduction to prepare formic acid.

[0005] To achieve the above-mentioned purpose, the application adopts the following technical solutions: In a first aspect, the application provides a device for continuously and stably operating electrocatalytic carbon dioxide reduction to prepare formic acid, which comprises a gas cylinder, an electrolytic reactor system, an anode liquid tank, an activation liquid tank and a product tank; the electrolytic reactor system comprises a plurality of reaction stacks connected in parallel; The cathode inlets of the plurality of reaction stacks are connected with the outlet of the gas cylinder; the anode inlets of the plurality of reaction stacks are connected with the outlets of the anode liquid tank and the activation liquid tank; the first outlets of the plurality of reaction stacks are connected with a gas-liquid separation tank; and the second outlets of the plurality of reaction stacks are connected with the inlets of the activation liquid tank and the product tank.

[0006] Preferably, the gas outlet of the gas-liquid separation tank is connected with the gas cylinder.

[0007] Preferably, the second outlets of the reaction stacks are connected to an anolyte tank.

[0008] Preferably, the second outlets of the reaction stacks are provided with float flow meters.

[0009] Preferably, the cathode inlets of the reaction stacks are provided with gas flow meters.

[0010] Preferably, the float flow meters and the gas flow meters are connected to an MES production management process unit; the MES production management process unit is used to set electrolytic reduction voltage and current parameters.

[0011] Preferably, the application further comprises a pure water tank; the outlet of the pure water tank is connected to the anolyte tank.

[0012] Preferably, a liquid supplement pump is arranged between the outlet of the pure water tank and the anolyte tank.

[0013] Preferably, the anode inlets of the reaction stacks are provided with circulating constant pressure pumps.

[0014] In a second aspect, the application provides a method for continuously and stably operating electrocatalytic reduction of carbon dioxide to prepare formic acid, comprising the following steps: Activation stage: Open the gas cylinder to supply carbon dioxide gas to the cathodes of the reaction stacks, and open the activation liquid tank to pump activation liquid to the anodes of the reaction stacks, to perform an activation reaction; the reacted activation liquid is returned to the activation liquid tank; Electrolysis stage: Close the activation liquid tank and open the anolyte tank to supply ultrapure water to the anodes of the reaction stacks; apply an electrolysis voltage to the reaction stacks to perform an electrolysis reaction; the generated formic acid is transported to a product tank through the second outlets of the reaction stacks; the generated gas-liquid mixture is transported to a gas-liquid separation tank through the first outlets of the reaction stacks for separation.

[0015] Compared with the prior art, the application has the following beneficial effects: The flexible regulation of production capacity is realized by the parallel arrangement of the reaction stacks and the cooperative operation mode; the raw material recycling is realized by the recovery of unreacted gas through the gas-liquid separation tank; the electrolysis demand of different process stages is met by the selective switching mode through the setting of the anolyte tank and the activation liquid tank double supply system; the single pass / circulating preparation of formic acid is realized by connecting the anode products of the stacks to the activation liquid tank and the product tank through the multi-channel output design. The application realizes the efficient and stable operation of electrocatalytic reduction of carbon dioxide to prepare formic acid, has the significant advantages of safety, environmental protection and high product concentration, and breaks through the production capacity limitation of the traditional process, thereby providing a reliable technical solution for the industrial application of electrocatalytic reduction of CO2 to prepare formic acid. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0017] Figure 1 Figure 1 is a structural schematic diagram of the device of the present application; Figure 2 Figure 4 is a current density diagram of Example 3; Figure 3 Figure 5 is a solution concentration diagram of the preparation of formic acid by electrocatalytic reduction of carbon dioxide under different reduction voltages in Examples 1-5.

[0018] 1, gas cylinder; 2, electrolytic reactor system; 3, pure water tank; 4, anode liquid tank; 5, activated liquid tank; 6, product tank; 7, gas-liquid separation tank; 8, float flow meter; 9, gas flow meter; 10, liquid supplement pump; 11, circulating constant pressure pump. DETAILED DESCRIPTION

[0019] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art on the basis of the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0021] It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0022] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "horizontal", "inner" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, or the orientation or position relationship of the product of the present application when it is usually placed, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0023] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly inclined. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0024] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, if the terms "arrangement", "installation", "connection", "connection" appear, they should be understood in a broad sense, for example, they can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] The present application will be described in further detail below in conjunction with the drawings: The first object of the present application is to provide a device for continuously and stably operating electrocatalytic reduction of carbon dioxide to prepare formic acid, which comprises Figure 1 As shown in the figure, including gas cylinder 1, electrolytic reactor system 2, anode liquid tank 4, activation liquid tank 5 and product tank 6; the electrolytic reactor system 2 comprises a plurality of reaction stacks connected in parallel; The cathode inlet of each of the plurality of reaction stacks is connected with the outlet of the gas cylinder 1; the anode inlet of each of the plurality of reaction stacks is connected with the outlet of the anode liquid tank 4 and the outlet of the activation liquid tank 5; the first outlet of each of the plurality of reaction stacks is connected with the gas-liquid separation tank 7; the second outlet of each of the plurality of reaction stacks is connected with the inlet of the activation liquid tank 5 and the product tank 6.

[0026] The electrocatalytic carbon dioxide reduction formic acid production device provided by the present invention utilizes a multi-reactor design to achieve continuous and stable operation of the reaction system and flexible production capacity control. A gas cylinder 1 provides high-purity carbon dioxide as the reaction raw material; several parallel-connected reactors form an electrolytic reactor system 2, allowing the number of operating reactors to be flexibly adjusted according to actual production needs, thereby flexibly adjusting production scale and improving reaction efficiency. An anolyte tank 4 and an activation liquid tank 5, respectively, store electrolyte (ultrapure water) and activation liquid, selectively supplying them to meet the needs of different process stages. A product tank 6 collects the generated formic acid product. A gas-liquid separator 7 separates the small amount of hydrogen and carbon monoxide byproducts produced by the carbon dioxide reduction reaction from the small amount of formic acid solution carried over the ion exchange membrane during the reaction. The unreacted carbon dioxide gas can be transported to the gas cylinder 1 through the gas outlet of the gas-liquid separator 7 for recycling.

[0027] The several reaction stacks used in the present invention are all made of high-purity titanium material, a dense oxide film can be formed on the surface of the material, and the material exhibits excellent chemical inertness in the electrolytic environment, ensuring that the stack does not undergo corrosion reaction with the electrolyte during long-term operation.

[0028] For example, in actual industrial applications, the number of operating fuel cells can be flexibly adjusted according to production needs to adapt to different production capacity requirements.

[0029] The second outlets of several reactor stacks are connected to the anolyte tank 4, enabling formic acid production to be divided into single-pass and recirculating modes. In the single-pass mode, the formic acid product is directly collected in the product tank 6, suitable for conditions requiring high purity and rapid output. In the recirculating mode, a portion of the product flows back to the anolyte tank 4 to continue the reaction, extending the reaction path to increase conversion efficiency.

[0030] Several reactor stacks are equipped with float flowmeters 8 at their second outlets, which can adjust and provide feedback on the flow status of the electrolyte in each stack in real time; several reactor stacks are equipped with gas flowmeters 9 at their cathode inlets, which can accurately display the CO2 supply. Both the float flowmeter 8 and the gas flowmeter 9 are connected to the MES production management process unit, which dynamically optimizes the electrolysis voltage and current settings by collecting these key parameters in real time, forming a closed-loop control system and improving the operating stability and energy efficiency of the device. Both the gas flowmeter 9 and the float flowmeter 8 can be controlled separately, freely selecting the collaborative operation mode of a single or multiple reactors, independently adjusting the process parameters for differentiated production, and maintaining synchronous operation to achieve capacity superposition.

[0031] In one embodiment of the present invention, a pure water tank 3 is further included; the outlet of the pure water tank 3 is connected to the anolyte tank 4, with a refill pump 10 provided therebetween. The refill pump 10 replenishes ultrapure water to the anolyte tank 4, effectively maintaining the stability of the anolyte level and concentration during the electrolysis process and preventing insufficient water consumption during electrolysis from affecting reaction efficiency.

[0032] The circulation constant pressure pump 11 is arranged at the anode inlet of each reaction stack, and the circulation constant pressure pump 11 can eliminate pressure fluctuation caused by electrolysis reaction or temperature change by continuous adjustment, keep the constant of mass transfer condition of the electrode surface, realize the accurate and stable control of the liquid delivery pressure in the single reaction stack, and thus improve the reaction efficiency and yield stability of the single reaction stack.

[0033] The second object of the application is to provide a method for continuously and stably operating the electrocatalytic reduction of carbon dioxide to prepare formic acid, which comprises the following steps: Activation stage: Open the gas cylinder 1 to introduce carbon dioxide gas into the cathode of each reaction stack, and open the activation liquid tank 5 to pump the activation liquid into the anode of each reaction stack, and perform the activation reaction, and then the activated liquid is returned to the activation liquid tank 5; Electrolysis stage: Close the activation liquid tank 5, open the anode liquid tank 4 to introduce ultrapure water into the anode of each reaction stack, and apply an electrolysis voltage to each reaction stack to perform the electrolysis reaction, and the generated formic acid is transported to the product tank 6 for storage through the second outlet of the reaction stack, and the generated gas-liquid mixture is transported to the gas-liquid separation tank 7 for separation through the first outlet of the reaction stack.

[0034] In addition, part of the generated formic acid can also be transported to the anode liquid tank 4 through the second outlet of the reaction stack for a circulation reaction.

[0035] The activation liquid is a solution of potassium hydroxide, sodium hydroxide, potassium bicarbonate or sodium bicarbonate. The strong alkali activation liquid such as potassium hydroxide and sodium hydroxide can effectively maintain the alkaline microenvironment of the electrode surface, promote the dissolution and activation of CO2, and the buffer system such as potassium bicarbonate and sodium bicarbonate can stabilize the pH fluctuation in the reaction process. At the same time, the concentration of the activation liquid is controlled in the range of 0.6-1.4 mol / L, which not only ensures sufficient ionic conductivity to improve the current efficiency, but also avoids the corrosion of the electrode material and ion membrane caused by too high alkalinity.

[0036] For example, the electrocatalytic reduction voltage of carbon dioxide is 2-6V, the minimum voltage threshold can overcome the activation energy barrier, and the upper limit of 6V can prevent the deactivation of the catalyst caused by the overpotential of the electrode; the reduction current is 15-35A, which can realize high formic acid yield and inhibit the electrode polarization phenomenon caused by too large current density.

[0037] For example, the anode liquid flow of the single reaction stack is 4-20L / h, which ensures that the anode side electrolyte can continuously and stably provide water molecules to participate in the oxygen evolution reaction, and at the same time maintain sufficient protons (H +) to drive the cathode CO2 reduction process; the single reaction stack cathode gas flow is 60-100 mL / h, which ensures sufficient coverage and effective activation of CO2 on the electrode surface, and avoids the problem of uneven mass transfer or bubble accumulation caused by too fast gas flow.

[0038] The present application realizes efficient and stable operation of electrocatalytic carbon dioxide reduction to prepare formic acid by parallel connection of several reaction stacks and single-pass / cycle dual-mode switching, significantly improves production efficiency and product purity; at the same time, by precise supply of activation liquid and electrolyte, gas-liquid separation and recycling of unreacted gas, the reaction process is optimized and raw material consumption is reduced, providing reliable technical support for industrial application, with flexibility of large-scale production and long-term operation stability.

[0039] Example 1 According to the order of anode material, solid resin particles, ion exchange membrane, cathode material, they are respectively separated by polytetrafluoroethylene gaskets, fixed by bolts, and #1-#10 reaction stacks (#1 to #10, a total of 10 reaction stacks) are assembled. The assembled #1-#10 reaction stacks are connected in parallel to the electrolysis reaction stack system 2, the cathode inlet is connected with the outlet of gas cylinder 1, the anode inlet is connected with the outlet of anode liquid tank 4 and activation liquid tank 5, the first outlet is connected with gas-liquid separation tank 7, and the second outlet is connected with the inlet of anode liquid tank 4 and activation liquid tank 5 and product tank 6.

[0040] The connected electrolysis stack reaction system 2 is activated, 0.6 mol / L potassium hydroxide activation liquid is introduced into the anode, and carbon dioxide gas is introduced into the cathode, and the activation time is 30 s. The electrolyte of the activated electrolysis reaction stack system 2 is switched to ultrapure water, the MES production management process unit interface is opened, the reduction potential range is set to 2 V, the current range is set to 15 A, the electrocatalytic reduction is started, the formic acid solution product of electrolysis ultrapure water is collected into the product tank 6, and its concentration is measured.

[0041] Example 2 According to the order of anode material, solid resin particles, ion exchange membrane, cathode material, they are respectively separated by polytetrafluoroethylene gaskets, fixed by bolts, and #1-#10 reaction stacks (#1 to #10, a total of 10 reaction stacks) are assembled. The assembled #1-#10 reaction stacks are connected in parallel to the electrolysis reaction stack system 2, the cathode inlet is connected with the outlet of gas cylinder 1, the anode inlet is connected with the outlet of anode liquid tank 4 and activation liquid tank 5, the first outlet is connected with gas-liquid separation tank 7, and the second outlet is connected with the inlet of anode liquid tank 4 and activation liquid tank 5 and product tank 6.

[0042] The connected electrolysis stack reaction system 2 is activated, the anode is connected to 0.8 mol / L potassium hydroxide activation solution, the cathode is connected to carbon dioxide gas, and the activation time is 40 s; The electrolyte of the activated electrolysis reaction stack system 2 is switched to ultrapure water, the MES production management process unit interface is opened, the reduction potential range is set to 3V, the current range is set to 20A, the electrocatalytic reduction is started, the electrolysis ultrapure water formic acid solution product is collected into the product tank 6, and the concentration is measured.

[0043] Example 3 The #1~#10 reaction stacks are assembled according to the order of anode material, solid resin particles, ion exchange membrane, and cathode material, which are respectively separated by polytetrafluoroethylene gaskets and fixed by bolts. There are a total of 10 reaction stacks from #1 to #10. The assembled #1~#10 reaction stacks are connected in parallel to the electrolysis reaction stack system 2, the cathode inlet is connected to the outlet of the gas cylinder 1, the anode inlet is connected to the outlet of the anode liquid tank 4 and the outlet of the activation liquid tank 5, the first outlet is connected to the gas-liquid separation tank 7, and the second outlet is connected to the inlet of the anode liquid tank 4 and the inlet of the activation liquid tank 5 and the product tank 6.

[0044] The connected electrolysis stack reaction system 2 is activated, the anode is connected to 1.0 mol / L potassium hydroxide activation solution, the cathode is connected to carbon dioxide gas, and the activation time is 50 s; The electrolyte of the activated electrolysis reaction stack system 2 is switched to ultrapure water, the MES production management process unit interface is opened, the reduction potential range is set to 4V, the current range is set to 25A, the electrocatalytic reduction is started, the electrolysis ultrapure water formic acid solution product is collected into the product tank 6, and the concentration is measured.

[0045] Example 4 The #1~#10 reaction stacks are assembled according to the order of anode material, solid resin particles, ion exchange membrane, and cathode material, which are respectively separated by polytetrafluoroethylene gaskets and fixed by bolts. There are a total of 10 reaction stacks from #1 to #10. The assembled #1~#10 reaction stacks are connected in parallel to the electrolysis reaction stack system 2, the cathode inlet is connected to the outlet of the gas cylinder 1, the anode inlet is connected to the outlet of the anode liquid tank 4 and the outlet of the activation liquid tank 5, the first outlet is connected to the gas-liquid separation tank 7, and the second outlet is connected to the inlet of the anode liquid tank 4 and the inlet of the activation liquid tank 5 and the product tank 6.

[0046] The connected electrolysis stack reaction system 2 is activated, the anode is connected to 1.2 mol / L potassium hydroxide activation solution, the cathode is connected to carbon dioxide gas, and the activation time is 60 s; The electrolyte of the activated electrolysis reactor system 2 is switched to ultrapure water, the MES production management process unit interface is opened, the reduction potential range is set to 5V, the current range is set to 30A, the electrocatalytic reduction is started, the electrolysis of the ultrapure water formic acid solution product is collected into the product tank 6, and the concentration is measured.

[0047] Example 5 According to the order of anode material, solid resin particles, ion exchange membrane, and cathode material, the polytetrafluoroethylene gasket is used to separate them, and the #1~#10 reaction stacks (a total of 10 reaction stacks) are assembled by bolts. The assembled #1~#10 reaction stacks are connected in parallel to the electrolysis reactor system 2, the cathode inlet is connected to the gas cylinder 1 outlet, the anode inlet is connected to the anode liquid tank 4 outlet and the activation liquid tank 5 outlet, the first outlet is connected to the gas-liquid separation tank 7, and the second outlet is connected to the anode liquid tank 4, the activation liquid tank 5 inlet, and the product tank 6.

[0048] The connected electrolysis stack reaction system 2 is activated, the anode is connected to 1.4 mol / L potassium hydroxide activation liquid, and the cathode is connected to carbon dioxide gas, and the activation time is 50s. The electrolyte of the activated electrolysis reactor system 2 is switched to ultrapure water, the MES production management process unit interface is opened, the reduction potential range is set to 6V, the current range is set to 35A, the electrocatalytic reduction is started, the electrolysis of the ultrapure water formic acid solution product is collected into the product tank 6, and the concentration is measured.

[0049] As shown in Figure 2 , the current density range of example 3 is 50~120 mA / cm 2 , which has approached the requirements of industrial production, indicating that the electrocatalytic CO2 reduction system has high reaction activity and industrial application potential, verifying the feasibility of the multi-reaction stack for industrial scale production.

[0050] As shown in Figure 3 , it is the concentration diagram of the formic acid solution prepared by electrocatalytic reduction of carbon dioxide at different reduction potentials in examples 1~5, and the concentration of the formic acid solution prepared in example 3 at a reduction voltage of 4V is the highest, which is 1.1mg / L.

[0051] The above is only a preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A device for producing formic acid by electrocatalytic reduction of carbon dioxide in continuous and stable operation, characterized in that: It comprises a gas cylinder (1), an electrolytic reactor system (2), an anode liquid tank (4), an activation liquid tank (5) and a product tank (6); the electrolytic reactor system (2) comprises a plurality of reactor stacks connected in parallel; Several cathode inlets of the reactor stack are connected to the outlet of the gas cylinder (1); several anode inlets of the reactor stack are connected to the outlet of the anode liquid tank (4) and the outlet of the activation liquid tank (5); several first outlets of the reactor stack are connected to the gas-liquid separation tank (7); and several second outlets of the reactor stack are connected to the inlet of the activation liquid tank (5) and the product tank (6).

2. The device for producing formic acid by continuous and stable electrocatalytic carbon dioxide reduction according to claim 1, characterized in that: The gas outlet of the gas-liquid separation tank (7) is connected to the gas cylinder (1).

3. The device for producing formic acid by continuous and stable electrocatalytic carbon dioxide reduction according to claim 1, characterized in that: The second outlets of the plurality of reactor stacks are all connected to the anode liquid tank (4).

4. The device for producing formic acid by continuous and stable electrocatalytic carbon dioxide reduction according to claim 1, characterized in that: Several of the reactor stack second outlets are each provided with a float flowmeter (8).

5. The device for producing formic acid by continuous and stable electrocatalytic carbon dioxide reduction according to claim 4, characterized in that: Several cathode inlets of the reactor stack are each provided with a gas flow meter (9).

6. The device for producing formic acid by continuous and stable electrocatalytic carbon dioxide reduction according to claim 5, characterized in that: The float flowmeter (8) and the gas flowmeter (9) are both connected to the MES production management process unit; the MES production management process unit is used to set the electrolytic reduction voltage and current parameters.

7. The device for producing formic acid by continuous and stable electrocatalytic reduction of carbon dioxide according to claim 1, characterized in that: It also includes a pure water tank (3); the outlet of the pure water tank (3) is connected to the anode liquid tank (4).

8. The device for producing formic acid by continuous and stable electrocatalytic carbon dioxide reduction according to claim 7, characterized in that: A rehydration pump (10) is provided between the outlet of the pure water tank (3) and the anode liquid tank (4).

9. The device for producing formic acid by continuous and stable electrocatalytic reduction of carbon dioxide according to claim 1, characterized in that: A circulating constant pressure pump (11) is provided at each of the anode inlets of the reactor stack.

10. A method for producing formic acid by continuous and stable electrocatalytic reduction of carbon dioxide, characterized in that: The device according to any one of claims 1 to 9 comprises the following steps: Activation stage: Open the gas cylinder (1) to introduce carbon dioxide gas to the cathodes of the plurality of reactors, and simultaneously open the activation liquid tank (5) to pump activation liquid to the anodes of the plurality of reactors to perform an activation reaction, and the activated liquid after the reaction flows back to the activation liquid tank (5); Electrolysis stage: The activation liquid tank (5) is closed, the anode liquid tank (4) is opened, and ultrapure water is introduced into the anodes of the plurality of reactors. An electrolysis voltage is applied to the plurality of reactors to perform an electrolysis reaction. The generated formic acid is transported to the product tank (6) for storage through the second outlet of the reactor, and the generated gas-liquid mixture is transported to the gas-liquid separation tank (7) for separation through the first outlet of the reactor.

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