Electro-catalysis device, solar-driven enzyme-electro-catalysis CO2 reduction device and application

Abstract

The invention belongs to the field of electro-catalysis, and particularly relates to an electro-catalysis device, a solar-driven enzyme-electro-catalysis CO2 reduction device and application. According to the device, efficient formic acid production under the condition of lower overpotential is realized by coupling enzyme catalysis and electro-catalysis technologies. The device disclosed by the invention is characterized in that an efficient and stable enzyme-electrocatalysis system is constructed by using a cathode modified by a carbon nano tube and an electrode fixed with formate dehydrogenase. Furthermore, through integration of a photovoltaic power generation assembly, a voltage regulator and a solar storage battery assembly, the CO2 reduction reaction with solar energy as the only energy source is achieved, and formic acid is produced. The device not only solves the problems of high overpotential, poor enzyme-electrocatalysis stability, low product selectivity, low catalytic efficiency and the like in the prior art, but also provides a solution which is stable in reaction system, mild in reaction condition, high in product selectivity and high in catalytic efficiency.

Description

Technical Field

[0001] The present invention belongs to the field of electrocatalysis, and specifically relates to an electrocatalytic device, a solar-driven enzyme-electrocatalytic CO2 reduction device and applications. Background Art

[0002] With the rapid development of social economy, the excessive consumption of fossil energy has triggered a global energy crisis and environmental problems (such as the greenhouse effect). Carbon dioxide (CO2), as the main component of greenhouse gases, will lead to global warming, ocean acidification, glacier melting, sea level rise and other problems. The development of sustainable energy and the capture and storage of CO2 have received widespread attention. Using renewable resources to synthesize chemicals, reduce greenhouse gas emissions and utilize CO2 in the atmosphere / industrial exhaust is a promising strategy to solve energy and environmental problems. This strategy converts CO2 into value-added chemicals, can form a carbon sink or a closed-loop production system, and has environmental and industrial benefits.

[0003] Electrocatalytic technology has shown great potential in solving global climate change and energy crisis problems. By converting CO2 into valuable chemicals through electrocatalytic processes, it can not only reduce greenhouse gas emissions, but also provide a new way for energy supply. Solar energy is a clean, renewable and sustainable energy. China has abundant solar energy resources, and the solar radiation energy reaching the surface every year is about 50×10 15 MJ, the total solar radiation in various places is 3350~8440MJ / m 2 , the median value is 5860MJ / m 2 . The effective development and utilization of solar energy resources is of great significance to solving the global energy crisis and environmental problems. The combination of solar energy resources and electrocatalytic technology provides an innovative solution to global climate change and energy crisis. Through the solar-driven electrocatalytic process, CO2 can be effectively converted into chemicals with commercial value. This process not only makes full use of the widely distributed solar energy resources on the earth, but also realizes the efficient conversion of CO2 through enzyme-electrocatalytic technology, promoting the efficient use of energy and the effective reduction of carbon emissions.

[0004] The optimization of the prior art for photoelectrocatalysis mainly focuses on the optimization of electrode materials and the direct addition of enzymes in the system, for example: using semiconductor materials loaded with gold nanoparticles as photoanode (CN118086930A), preparing CuO / ZnO composite catalyst heterojunction thin films as photocathode (CN118186439A), constructing a porous sponge-like E-WO3 photoanode-cathode photoelectrocatalytic system and using solar panels for power supply (CN116657174A), adding enzymes and coenzymes in the cathode chamber (CN114405437A). However, these photoelectrocatalytic systems generally face a large overpotential requirement, and at the same time, they are insufficient in product selectivity and catalytic efficiency. These problems limit the widespread application of this technology. In addition, free enzyme-electrocatalytic devices also have the problem of insufficient stability in practical applications. As a biocatalyst, the stability and activity maintenance of enzymes in the electrocatalytic process are the key to achieving efficient conversion. The current free enzyme-electrocatalytic system is susceptible to environmental factors during long-term operation, resulting in a decrease in enzyme activity, which in turn affects the stability and efficiency of the entire catalytic system. In response to these problems, optimizing the material composition and structure of the catalyst and developing new enzyme immobilization technology can help reduce the system's overpotential requirements, improve product selectivity and catalytic efficiency, and improve the stability and reusability of enzymes in the electrocatalytic process, which is an important direction for promoting the development of electrocatalytic technology. This technical solution improves the efficiency and product selectivity of the CO2 reduction reaction by optimizing catalyst materials and enzyme immobilization technology, while enhancing the stability of the enzyme-electrocatalytic system. This strategy, which combines renewable energy and advanced catalytic technology, provides a new way to achieve environmentally friendly and economically viable chemical synthesis, and helps to promote the world's progress towards sustainable development goals.

[0005] In summary, the solar-driven enzyme-electrocatalytic CO2 reduction technology, with its high efficiency, environmental friendliness and sustainability, provides a solution with broad application prospects for addressing global climate change and energy crisis. The development and application of this technology is expected to have a profound impact in many fields such as the chemical industry, energy production and environmental protection. Summary of the invention

[0006] In view of the above problems, the present invention provides an electrocatalytic device, a solar-driven enzyme-electrocatalytic CO2 reduction device and applications.

[0007] One of the purposes of the present invention is to provide an electrocatalytic device to achieve formic acid synthesis.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] An electrocatalytic device comprises a cathode chamber, an anode chamber, a cathode and an anode, wherein the cathode chamber and the anode chamber are separated by a proton exchange membrane, the cathode and the anode are respectively arranged in the cathode chamber and the anode chamber, the anode chamber is provided with an electrolyte aqueous solution, the cathode chamber is provided with a buffer solution, the cathode is modified with carbon nanotubes and formate dehydrogenase is fixed thereon, and the protein sequence of the formate dehydrogenase is as shown in SEQ ID NO.1.

[0010] As a preferred technical solution, it also includes a reference electrode, which is an Ag / AgCl electrode, the anode is a Ni electrode, and the cathode is a pyrolytic graphite electrode modified with carbon nanotubes and fixed with formate dehydrogenase.

[0011] As a preferred technical solution, the cathode is prepared by the following steps:

[0012] S1: evenly apply the carbon nanotube suspension to the surface of the pyrolytic graphite electrode, and dry it under an infrared bulb to obtain a carbon nanotube-modified pyrolytic graphite electrode;

[0013] S2: The prepared carbon nanotube-modified pyrolytic graphite electrode is placed in a PBS buffer solution containing formate dehydrogenase, and oscillated in a water bath oscillator at 20 to 25° C. for 30 to 40 minutes, and then washed and freeze-dried to complete the immobilization of the enzyme.

[0014] As a preferred technical solution, the electrolyte aqueous solution in the anode chamber is Na2SO4 or KHCO3 solution with a concentration of 0.1-2 mol / L, and the buffer composition in the cathode chamber is: 100-200 mmol / L 2-morpholineethanesulfonic acid, 1-2 mol / LNaCl, and 20-50 mmol / L Na2CO3.

[0015] The second purpose of the present invention is to provide a solar-driven enzyme-electrocatalytic CO2 reduction device to achieve green and sustainable energy utilization through the use of solar energy.

[0016] In order to achieve the above object, the present invention adopts the following technical solution:

[0017] A solar-driven enzyme-electrocatalytic CO2 reduction device comprises a photovoltaic power generation component, a voltage regulator, the electrocatalytic device as described above and a solar battery; the electrocatalytic device is connected to the photovoltaic power generation component via the voltage regulator, and the solar battery is connected to the voltage regulator.

[0018] As a preferred technical solution, the photovoltaic power generation component is a polycrystalline silicon photovoltaic power generation panel, the dimensions of the photovoltaic power generation panel are: 920-1650mm in length, 680-992mm in width, and 30-50mm in thickness, and the power of the photovoltaic power generation panel is 100-300W.

[0019] As a preferred technical solution, the solar battery is a lithium iron phosphate battery.

[0020] As a preferred technical solution, the voltage of the electrocatalytic device is controlled within a range of 0.5 to 3V by a voltage regulator.

[0021] The third object of the present invention is to provide a use of a solar-driven enzyme-electrocatalytic CO2 reduction device.

[0022] In order to achieve the above object, the present invention adopts the following technical solution:

[0023] Application of the solar-driven enzyme-electrocatalytic CO2 reduction device as described above in formic acid synthesis.

[0024] As a preferred technical solution, the application of the solar-driven enzyme-electrocatalytic CO2 reduction device in formic acid synthesis includes the following steps:

[0025] The cathode is modified with carbon nanotubes and formate dehydrogenase is fixed, and an electrolyte aqueous solution and a buffer solution are respectively added to the anode chamber and the cathode chamber of the electrocatalytic device. Solar energy is converted into electrical energy through photovoltaic panels and stored in solar batteries. At the same time, the voltage applied to the electrocatalytic device is adjusted by a voltage regulator. CO2 is combined with electrons in the cathode chamber to produce formic acid through the catalysis of formate dehydrogenase.

[0026] After the present invention adopts the above technical solution, it mainly has the following effects:

[0027] (1) The present invention uses a pyrolytic graphite electrode modified with carbon nanotubes and immobilized with formate dehydrogenase as a cathode, which effectively improves the electrochemical performance of the electrode, increases the effective surface area, and improves the stability of the enzyme-electrocatalytic device.

[0028] (2) The present invention uses solar photovoltaic panels to achieve electrocatalytic conversion of CO2 to formic acid without the need for an external power source, thereby reducing greenhouse gas emissions. Solar batteries provide stable electricity when light is insufficient, enhancing system stability and efficiency, and achieving green and sustainable energy utilization.

[0029] (3) The present invention innovatively combines electrocatalysis and enzyme catalysis technologies to effectively reduce the high overpotential requirement in the CO2 reduction process and reduce the reliance on precious metals. This technology significantly increases the reduction rate, reduces the generation of byproducts, and greatly improves the efficiency of formic acid production, opening up a new path for environmentally friendly chemical synthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of an electrocatalytic device according to an embodiment of the present invention.

[0031] Figure 2 Schematic diagram of the connection of a solar-driven enzyme-electrocatalytic CO2 reduction device according to an embodiment of the present invention.

[0032] Figure 3 Graph showing the change in CO2 conversion rate of a solar-driven enzyme-electrocatalytic CO2 reduction device under different light intensities according to an embodiment of the present invention.

[0033] Figure 4 This is a graph showing the change in CO2 conversion rate over time of a solar-driven enzyme-electrocatalytic CO2 reduction device in an outdoor experiment according to an embodiment of the present invention.

[0034] Figure 5 This is a diagram showing the production of formic acid by a solar-driven enzyme-electrocatalytic CO2 reduction device under laboratory controlled lighting conditions according to an embodiment of the present invention.

[0035] Figure 6 This is a diagram showing the production of formic acid by a solar-driven enzyme-electrocatalytic CO2 reduction device under outdoor lighting conditions according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention is further described in detail below through implementation cases. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Those skilled in the art should understand that the details and forms of the technical solution of the present invention can be modified or replaced without departing from the structural ideas and scope of use of the present invention, but these modifications and replacements all fall within the protection scope of the present invention.

[0037] An embodiment of the present invention provides an electrocatalytic device, such as Figure 1 As shown, the electrocatalytic device 100 includes a cathode chamber 101, an anode chamber 102, a cathode 103 and an anode 104, wherein the cathode chamber 101 and the anode chamber 102 are separated by a proton exchange membrane 105, the cathode 103 and the anode 104 are respectively arranged in the cathode chamber 101 and the anode chamber 102, the anode chamber 102 is provided with an electrolyte aqueous solution, the cathode chamber 101 is provided with a buffer solution, the cathode 103 is modified with carbon nanotubes and has formate dehydrogenase 106 fixed thereon, and the protein sequence of the formate dehydrogenase 106 is as shown in SEQ ID NO.1.

[0038] The electrocatalytic device is used to reduce CO2 to formic acid. In the anode chamber 102, the chemical reaction that occurs is: H2O→O2+H + In the cathode chamber 101, the chemical reaction that occurs is: CO2+H +→HCOOH. Formate dehydrogenase plays a catalytic role in the chemical reaction process. In this embodiment, the pyrolytic graphite electrode modified with carbon nanotubes and immobilized with formate dehydrogenase is used as the cathode, which effectively improves the electrochemical performance of the electrode, increases the effective surface area, and improves the stability of enzyme-electrocatalysis.

[0039] In this embodiment, the electrocatalytic device can adopt a three-electrode system, that is, it also includes a reference electrode, the reference electrode is an Ag / AgCl electrode, the anode is a Ni electrode, and the cathode is a pyrolytic graphite electrode modified with carbon nanotubes and fixed with formate dehydrogenase.

[0040] The present invention also provides a solar-driven enzyme-electrocatalytic CO2 reduction device, such as Figure 2 As shown, the solar-driven enzyme-electrocatalytic CO2 reduction device includes a photovoltaic power generation component 200, a voltage regulator 300, an electrocatalytic device 100 and a solar battery 400; the electrocatalytic device 100 is connected to the photovoltaic power generation component 200 via the voltage regulator 300, and the solar battery 400 is connected to the voltage regulator 300.

[0041] Exemplarily, the photovoltaic power generation component is a polycrystalline silicon photovoltaic power generation panel, the size of the photovoltaic power generation panel is: 920-1650 mm in length, 680-992 mm in width, and 30-50 mm in thickness, and the power of the photovoltaic power generation panel is 100-300 W. The solar battery is a lithium iron phosphate battery. The voltage of the electrocatalytic device is controlled at 0.5-3 V by a voltage regulator.

[0042] The following examples of the present invention will illustrate the feasibility and advancement of the present invention in conjunction with specific embodiments. Six specific examples are carried out, among which Example 1 describes the specific preparation method of the cathode, Example 2 describes the assembly method of the enzyme-electrocatalytic CO2 reduction device driven by solar energy, Example 3 conducts an experiment on the influence of different light intensities on the operation of the reduction device, Example 4 conducts an experiment on the influence of outdoor light intensity on the operation of the reduction device, Example 5 conducts an experiment on the determination of formic acid production under laboratory conditions, and Example 6 conducts an experiment on the determination of formic acid production under outdoor light conditions.

[0043] Example 1 Carbon nanotube modification and formate dehydrogenase immobilization on pyrolytic graphite electrode

[0044] The surface of the pyrolytic graphite electrode was polished. Subsequently, the electrode was cleaned with an ultrasonic cleaner for 5 minutes until the electrode surface was as smooth as a mirror. Finally, the carbon nanotube suspension was evenly coated on the surface of the graphite electrode and dried under an infrared bulb to obtain a carbon nanotube-modified pyrolytic graphite electrode.

[0045] The carbon nanotube-modified pyrolytic graphite electrode was immersed in PBS buffer (100 mmol / L, pH 6) containing formate dehydrogenase and oscillated in a water bath oscillator at 25° C. for 30 min. The electrode was washed three times with PBS buffer and freeze-dried to complete the enzyme immobilization.

[0046] Example 2 Assembly of a solar-driven enzyme-electrocatalytic CO2 reduction device

[0047] like Figure 2 As shown, the solar-driven enzyme-electrocatalytic CO2 reduction device components mainly include: photovoltaic power generation components, voltage regulators, electrocatalytic devices and solar batteries. In the actual assembly process, a polycrystalline silicon photovoltaic power generation panel with a size of 1650×992×40mm is used as a photovoltaic power generation component, which is connected to the electrocatalytic device through a voltage regulator, and the solar battery is connected to the voltage regulator.

[0048] Electrocatalytic device: The anode uses a commercial Ni electrode with a purity of 99.999%; the cathode uses a pyrolytic graphite electrode modified with carbon nanotubes and immobilized with formate dehydrogenase; the reference electrode is an Ag / AgCl electrode. 80 mL of 1 mol / L KHCO3 solution is poured into the anode chamber, and 80 mL of buffer (100 mmol / L 2-morpholineethanesulfonic acid, 1 mol / L NaCl, 20 mmol / L Na2CO3) is poured into the cathode chamber, and a proton exchange membrane is used.

[0049] Example 3 Effect of different light intensities on the operation of the reduction device

[0050] In the laboratory, a 200W xenon lamp (300-2500nm) was used to measure the effect of different light intensities on the operating stability of the device. The light intensity was changed by changing the distance between the xenon lamp and the solar photovoltaic panel, and the light intensity at different distances was measured using an illuminance meter. A total of 5 groups of experiments were set up, with light intensities of 1.0W / cm 2 , 1.5W / cm 2 , 2.0W / cm 2 , 2.5W / cm 2 、3.0W / cm 2 , a systematic evaluation of CO2 conversion under different light intensities ( Figure 3 ).

[0051] Before the experiment, humidified CO2 gas was introduced into the cathode chamber through a gas flow controller at a flow rate of 20 mL / min for 30 min to ensure sufficient replacement of the reaction gas.

[0052] The electrocatalytic reaction time was set to 30 min, and the liquid product was measured using nuclear magnetic resonance (NMR) to calculate the CO2 conversion rate.

[0053] Example 4 Effect of outdoor light intensity on the operation of the reduction device

[0054] The experimental device was placed on an open flat ground outdoors. The CO2 conversion rate of the device was measured at different time points to observe the effects of different lighting conditions on the operating stability of the device under outdoor conditions.

[0055] Before the experiment, humidified CO2 gas was introduced into the cathode chamber through a gas flow controller at a flow rate of 20 mL / min for 30 min to ensure sufficient replacement of the reaction gas.

[0056] The experiment was conducted from 8 am to 6 pm, with sampling every 2 hours. The liquid product was measured using nuclear magnetic resonance (NMR) to observe the changes in the CO2 conversion rate of the device at different time points ( Figure 4 ).

[0057] Example 5 Determination of formic acid production under laboratory conditions

[0058] A 200W xenon lamp (300-2500nm) was used as the light source, and the light intensity was controlled to be 2.5W / cm 2 , the humidified CO2 gas was input into the cathode chamber through the gas flow controller at a flow rate of 20mL / min for 30min to ensure that the reaction gas was fully replaced. The anolyte (1mol / L KHCO3 solution) flowed through the anode at a constant flow rate of 10mL / min, the cathode buffer (100mmol / L 2-morpholineethanesulfonic acid, 1mol / LNaCl, 20mmol / L Na2CO3) flowed through the cathode at a constant flow rate of 10mL / min, and the humidified CO2 was input into the cathode chamber through the gas flow controller at a flow rate of 2mL / min for constant flow rate supply, and the applied voltage was controlled to be 0.8V by the voltage regulator.

[0059] The product formic acid was measured every 24 hours for a total of 120 hours, and the product formic acid was detected by nuclear magnetic resonance. The product was collected from the cathode flow and analyzed by nuclear magnetic resonance spectroscopy with dimethyl sulfoxide (DMSO) as the internal standard ( Figure 5 ).

[0060] Example 6 Determination of formic acid production under outdoor lighting conditions

[0061] The experimental device was placed on an open flat ground outdoors, and the humidified CO2 gas was input into the cathode chamber through a gas flow controller at a flow rate of 20 mL / min for 30 minutes to ensure that the reaction gas was fully replaced. The anolyte (1 mol / L KHCO3 solution) flowed through the anode at a constant flow rate of 10 mL / min, the cathode buffer (100 mmol / L 2-morpholineethanesulfonic acid, 1 mol / L NaCl, 20 mmol / L Na2CO3) flowed through the cathode at a constant flow rate of 10 mL / min, and the humidified CO2 was input into the cathode chamber through a gas flow controller at a flow rate of 2 mL / min for constant flow rate supply, and the applied voltage was controlled to be 0.8 V by a voltage regulator.

[0062] The product formic acid was measured every 12 hours for a total of 72 hours, and the product formic acid was detected by nuclear magnetic resonance. The product was collected from the cathode flow and analyzed by nuclear magnetic resonance spectroscopy with dimethyl sulfoxide (DMSO) as the internal standard ( Figure 6 ).

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electrocatalytic device, characterized in that: The invention comprises a cathode chamber, an anode chamber, a cathode and an anode, wherein the cathode chamber and the anode chamber are separated by a proton exchange membrane, the cathode and the anode are arranged in the cathode chamber and the anode chamber respectively, the anode chamber is provided with an electrolyte aqueous solution, the cathode chamber is provided with a buffer solution, the cathode is modified with carbon nanotubes and formate dehydrogenase is fixed thereon, and the protein sequence of the formate dehydrogenase is as shown in SEQ ID NO.

1.

2. An electrocatalytic device according to claim 1, characterized in that: The invention also comprises a reference electrode, wherein the reference electrode is an Ag / AgCl electrode, the anode is a Ni electrode, and the cathode is a pyrolytic graphite electrode modified by carbon nanotubes and fixed with formate dehydrogenase.

3. An electrocatalytic device according to claim 1, characterized in that: The cathode is prepared by the following steps: S1: evenly apply the carbon nanotube suspension to the surface of the pyrolytic graphite electrode, and dry it under an infrared bulb to obtain a carbon nanotube-modified pyrolytic graphite electrode; S2: The prepared carbon nanotube-modified pyrolytic graphite electrode is placed in a PBS buffer solution containing formate dehydrogenase, and oscillated in a water bath oscillator at 20 to 25° C. for 30 to 40 minutes, and then washed and freeze-dried to complete the immobilization of the enzyme.

4. An electrocatalytic device according to claim 1, characterized in that: The electrolyte aqueous solution in the anode chamber is a Na2SO4 or KHCO3 solution with a concentration of 0.1-2 mol / L, and the buffer composition in the cathode chamber is: 100-200 mmol / L 2-morpholineethanesulfonic acid, 1-2 mol / L NaCl, and 20-50 mmol / L Na2CO3.

5. A solar-driven enzyme-electrocatalytic CO2 reduction device, characterized in that: It comprises a photovoltaic power generation component, a voltage regulator, an electrocatalytic device as described in any one of claims 1 to 4, and a solar battery; the electrocatalytic device is connected to the photovoltaic power generation component through the voltage regulator, and the solar battery is connected to the voltage regulator.

6. A solar-driven enzyme-electrocatalytic CO2 reduction device as claimed in claim 5, characterized in that: The photovoltaic power generation component is a polycrystalline silicon photovoltaic power generation panel. The dimensions of the photovoltaic power generation panel are: 920-1650 mm in length, 680-992 mm in width, and 30-50 mm in thickness. The power of the photovoltaic power generation panel is 100-300W.

7. A solar-driven enzyme-electrocatalytic CO2 reduction device as claimed in claim 5, characterized in that: The solar energy storage battery is a lithium iron phosphate battery.

8. A solar-driven enzyme-electrocatalytic CO2 reduction device as claimed in claim 5, characterized in that: The voltage of the electrocatalytic device is controlled within a range of 0.5 to 3V by a voltage regulator.

9. Use of the solar-driven enzyme-electrocatalytic CO2 reduction device according to any one of claims 5 to 8 in formic acid synthesis.

10. The use according to claim 9, characterized in that: The following steps are involved: The cathode is modified with carbon nanotubes and formate dehydrogenase is fixed, and an electrolyte aqueous solution and a buffer solution are respectively added to the anode chamber and the cathode chamber of the electrocatalytic device. Solar energy is converted into electrical energy through photovoltaic panels and stored in solar batteries. At the same time, the voltage applied to the electrocatalytic device is adjusted by a voltage regulator. CO2 is combined with electrons in the cathode chamber to produce formic acid through the catalysis of formate dehydrogenase.

Images