CN117626343A - Preparation method of bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide - Google Patents

Preparation method of bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide Download PDF

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CN117626343A
CN117626343A CN202311589549.4A CN202311589549A CN117626343A CN 117626343 A CN117626343 A CN 117626343A CN 202311589549 A CN202311589549 A CN 202311589549A CN 117626343 A CN117626343 A CN 117626343A
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carbon dioxide
electrochemical reduction
catalyst
electrode
bimetallic oxide
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陶亨聪
贾天博
李珂璠
王涵
王宇杰
沈斌浩
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Zhejiang Ocean University ZJOU
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Abstract

The invention discloses a preparation method of a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide, which comprises the following steps: dissolving a metal salt into a metal salt solution; carrying out chemical precipitation on the metal salt solution in an air-exposed environment; carrying out pyrolysis treatment on the precipitate after precipitation in an air atmosphere to obtain a catalyst; and placing the obtained catalyst on an electrode support for electrocatalytic treatment, so that the catalyst surface of a working electrode is subjected to carbon dioxide electrochemical reduction reaction in an electrolyte solution of an H-type electrolytic cell, and the middle of the H-type electrolytic cell is separated into a cathode and an anode by an exchange membrane. The bi-metal oxide electrocatalyst capable of regulating and controlling the selectivity of the electrochemical reduction product of the carbon dioxide can be obtained by coprecipitation at room temperature and pyrolysis, the preparation method is simple, the reaction condition is mild, the prepared catalyst has good electrochemical reduction activity of the carbon dioxide and service life, and the selectivity of the product can be obviously changed by regulating and controlling the proportion of metals.

Description

Preparation method of bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide
Technical Field
The invention belongs to the technical field of inorganic environment-friendly electrocatalytic materials, and particularly relates to a preparation method of a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide.
Background
In the world energy consumption structure, the ratio of fossil fuel is nearly eight, compared with the traditional CO2 treatment technology, the electrocatalytic reduction technology has mild and controllable reaction conditions, the electric energy for driving the reaction is green energy, secondary pollution can not be caused to the environment, and the method is one of strategies with great potential for helping to realize 3060 double-carbon targets.
CO2 is one of the most widely known greenhouse gases, and the use of large amounts of fossil fuels causes the CO2 concentration in the atmosphere to rise very rapidly, causing a series of serious environmental problems such as global warming, sea level rising, etc., and if the emission of CO2 is not continuously controlled or the CO2 concentration in the atmosphere is reduced, the ecological environment is exposed to irreversible damage, and the existence of human beings and all organisms is greatly threatened.
The CO2 conversion realized by the electrocatalytic technology is mainly realized by converting CO2 into chemical raw materials or fuels with high added value such as CO, CH4, HCOOH, C2H5OH and the like through an electron transfer process of CO2 molecules adsorbed on the surface of an electrocatalyst. Numerous methods related to electrocatalyst preparation are mentioned in the prior art, but few methods related to preparation of bimetallic oxide materials for realizing selective conversion of CO2 in electrochemical reduction process are available, selective production of products is realized, cost for separating subsequent products can be effectively reduced, and the method has high value for application of electrocatalyst in industrial production.
Disclosure of Invention
The invention aims to provide a Cu-Cd bimetallic oxide material which is selective to a product in the electrochemical reduction process of carbon dioxide, has stronger CO2 adsorption capacity, can dynamically influence the selectivity of the product by the proportion of Cu and Cd, has high-efficiency electrochemical reduction capacity to CO2 under a proper voltage condition, and has good stability. In order to achieve the purpose, the specific technical scheme of the invention is as follows:
the preparation method of the bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide specifically comprises the following steps:
s1, dissolving metal salt into a metal salt solution;
s2, carrying out chemical precipitation on the metal salt solution in an air-exposed environment;
s3, carrying out pyrolysis treatment on the precipitated sediment in an air atmosphere to obtain a catalyst;
s4, placing the catalyst obtained in the step S3 on an electrode support for electrocatalytic treatment, so that the catalyst surface of the working electrode is subjected to carbon dioxide electrochemical reduction reaction in an electrolyte solution of an H-type electrolytic cell, and the middle of the H-type electrolytic cell is separated into a cathode and an anode by an exchange membrane.
Further, in the step S1, any two of copper, cadmium, iron, nickel, bismuth and cobalt are selected as metal salt components, and the concentration of the metal salt is 1-1500 mM.
Further, the chemical precipitant in the step S2 is one or more of sodium carbonate, sodium bicarbonate, ammonium bicarbonate, potassium carbonate and potassium bicarbonate; the time of chemical precipitation is 1-48 h.
The metal salt solution is contacted with a chemical precipitant under the condition of air exposure, water-insoluble precipitate substances are generated through the double decomposition reaction of metal ions and carbonate ions, the concentration of the metal salt solution influences the precipitation speed and the metal content in the catalyst, in general, the higher the concentration is, the faster the precipitation speed is, the shorter the required time is, and precipitate precursors with different structural properties can be obtained by controlling the concentration of the metal salt solution.
Further, the specific operation of step S3 is as follows: and (3) putting the precipitate into a muffle furnace, continuously introducing air, heating to a set temperature, and then preserving heat, wherein the temperature of pyrolysis treatment is 200-1000 ℃, the heating rate of pyrolysis treatment is 1-10 ℃/min, and the heat preservation time is 1-6 h. If the temperature is too low, insufficient pyrolysis of the precipitate can result; if the temperature is too high, the energy consumption is high and the risk is high.
Precursors generated by chemical precipitation of copper, cadmium, nickel, cobalt, iron and bismuth are usually large-particle-size metal carbonic acid insoluble substances, the conductivity is poor, the specific surface area is small, the active sites are few, and pyrolysis is used for converting the carbonic acid insoluble substances into metal oxides with high conductivity, large specific surface area and multiple active sites; in addition, pyrolysis can cross oxide lattices of two metals to form a heterostructure, thereby affecting the catalytic performance of the catalyst.
Further, the specific operation of step S4 is as follows: preparing the pyrolyzed catalyst into catalyst ink, and uniformly attaching the catalyst ink to the surface of an electrode support to serve as a working electrode; the counter electrode and the reference electrode are arranged to form a three-electrode system, the middle of the cathode and the anode of the H-type electrolytic cell is separated by an exchange membrane, and the working electrode carries out carbon dioxide electrochemical reduction reaction in electrolyte solution.
The bimetallic oxide heterostructure can form a series catalytic effect, the surface of the bimetallic oxide heterostructure contains two active sites, one metal oxide active site promotes adsorption of CO2 on the surface and conversion of an intermediate, the other metal oxide active site captures the CO2 reduction intermediate generated by the first metal oxide and further converts the intermediate into a target product, so that pyrolysis is thorough during preparation, the proportion of two metal salts is controlled, and site competition is avoided.
Further, in the step S4, during the electrochemical reduction of carbon dioxide, the working electrode and the reference electrode are placed at the cathode, and the counter electrode is placed at the anode; the products of electrochemical reduction of carbon dioxide include one or more of formic acid, carbon monoxide, methane and ethylene.
Further, in the step S4, the counter electrode is one of a platinum sheet, a graphite rod, a platinum wire and a platinum mesh; the reference electrode adopts one of mercury/oxidized mercury, silver/silver chloride and saturated calomel electrode; the electrolyte solution adopts one or more of potassium bicarbonate, potassium hydroxide, sodium sulfate and potassium sulfate; the exchange membrane adopts one of a proton exchange membrane, an anion exchange membrane or a cation exchange membrane.
Preferably, potassium bicarbonate is used as the electrolyte solution, and the concentration of potassium bicarbonate is 0.05 to 2.5M.
Further, in the step S4, the electrode support is made of one of carbon paper, carbon cloth, carbon felt, glassy carbon electrode, copper foam, and nickel foam.
Further, in the step S4, the electrochemical reduction of carbon dioxide adopts potentiostatic reduction, the working potential of the electrochemical reduction of carbon dioxide is-1.2V to-1.6V vs. rhe, and the duration of the surface carbon dioxide reduction is 0.1h to 4h. The working potential and time of the surface carbon dioxide reduction process are controlled, and the performance requirement of the catalyst can be met. Taking working potential as an example, the working potential is too low, the transfer speed of driving electrons is low, electrons are not transferred yet, and an intermediate falls off from the surface of the catalyst; the working potential is too high, so that the occurrence of hydrogen evolution reaction is aggravated, and the conversion of carbon dioxide to carbon-containing products is affected; the time control is also based on the above considerations.
Compared with the prior art, the invention has the following advantages:
(1) The bimetallic oxide electrocatalyst capable of regulating and controlling the selectivity of the electrochemical reduction product of the carbon dioxide can be obtained by coprecipitation at room temperature and then pyrolysis.
(2) The working electrode prepared by the invention can change the selectivity of the product by only changing the feeding ratio of the two metals, avoids the complex preparation processes of size control, crystal face control, active site interface design and the like, and has high economic value and good industrial application prospect.
Drawings
FIG. 1 is an X-ray diffraction pattern of the electrocatalyst according to examples and comparative examples of the invention;
FIG. 2 is a transmission electron microscope image of the electrocatalyst according to the examples and comparative examples of the invention;
FIG. 3 is a scanning electron microscope image and an element distribution energy spectrum of an electrocatalyst according to an example and a comparative example of the invention;
FIG. 4 is an ESR spectrum of an electrocatalyst according to an example of the invention;
FIG. 5 is an electrochemical impedance diagram (a), selectivity (b), yield (c), energy efficiency diagram (d) of electrolysis of the electrocatalyst according to example and comparative example of the invention at an applied potential;
FIG. 6 is a graph of Faraday efficiencies of electrocatalysts of examples and comparative examples of the invention at different potentials.
Detailed Description
For a better understanding of the invention with its objects, structure and function, reference should be made to the accompanying drawings.
A method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide, comprising the steps of:
(1) The metal salt is dissolved into a metal salt solution.
In a specific embodiment, the metal cations of the metal salt are copper ions, cadmium ions, iron ions, nickel ions, bismuth ions, cobalt ions and the like, and the anions of the metal salt are nitrate ions, chloride ions, sulfate ions and the like; typical metal salts are combinations of copper ions, cadmium ions and nitrate ions, and the solvent is water at a concentration of 1 to 1500mM, typical concentrations include 1mM, 5mM, 10mM, 20mM, 50mM, 100mM, 200mM, 300mM, 400mM, 500mM, 600mM, 700mM, 800mM, 1000mM, 1500mM, etc.
(2) The metal salt solution is subjected to chemical precipitation in an air-exposed environment.
500mL of ultrapure water is put into a 1000mL beaker, the first metal salt solution is added once and stirred once, the vigorous stirring is continued until the metal salt is completely dissolved to form a clear solution, then the second metal salt is added in the process of vigorous stirring, the stirring is continued until the second metal salt is successfully dissolved to form the clear solution, 300mL of precipitant is taken, the precipitant is slowly added into the metal salt solution to form flocculent precipitate, and the stirring is continued in the air to complete the generation of the precipitate.
In a specific embodiment, the precipitant is selected from one or more of sodium carbonate, sodium bicarbonate, ammonium bicarbonate, potassium carbonate and potassium bicarbonate, and the stirring time is 1-48 h after the precipitant is added.
(3) And carrying out pyrolysis treatment on the precipitate after precipitation in an air atmosphere.
And placing the precipitate precursor in a crucible, placing the crucible in a muffle furnace, heating to a set temperature, and then preserving heat.
In the specific embodiment, in the pyrolysis treatment process, the temperature rising rate of the muffle furnace is 1-10 ℃/min, and the heat preservation time is 1-6 h; the temperature of the heat preservation is 200-1000 ℃.
(4) And placing the pyrolyzed product on an electrode support for electrocatalytic treatment, so that the catalyst surface of a working electrode is subjected to carbon dioxide electrochemical reduction reaction in an electrolyte solution of an H-type electrolytic cell, the middle of the H-type electrolytic cell is separated into a cathode and an anode by an exchange membrane, and the catalyst has the property of regulating and controlling the selectivity of the product. The specific operation steps are as follows: and taking the pyrolyzed product as a working electrode, arranging a counter electrode and a reference electrode to form a three-electrode system, immersing the working electrode in electrolyte, then introducing CO2 gas into the electrolyte, immersing the working electrode in the electrolyte, and performing electrochemical reaction.
In a specific embodiment, the electrode support may be any one of carbon paper, carbon cloth, carbon felt, glassy carbon electrode, foam copper and foam nickel, so that the catalyst can be better dispersed. The counter electrode is selected from one of a platinum sheet, a graphite rod, a platinum wire and a platinum mesh, wherein the platinum mesh is preferable; the reference electrode is selected from one of mercury/oxidized mercury, silver/silver chloride and saturated calomel electrode, preferably silver/silver chloride electrode. The electrolyte solution can be selected from one or more of potassium bicarbonate, potassium hydroxide, sodium sulfate and potassium sulfate, preferably potassium bicarbonate, and the concentration of the potassium bicarbonate is 0.05-2.5M. Typical concentrations include 0.05M, 0.1M, 0.2M, 0.5M, 1M, 1.5M, 2M, 2.5M, etc., with the electrolyte solution preferably being 0.1M potassium bicarbonate.
The electrochemical reduction of carbon dioxide adopts constant voltage reduction, the voltage level of the constant voltage reduction is-1.2 to-1.6V vs. RHE, and the constant voltage test time is 0.1h to 4h.
The specific embodiment of the invention also provides application of the catalyst prepared by the method, and the catalyst is used for biomass electrocatalytic oxidation reaction. The specific application method is as follows: the electrocatalyst is used as a working electrode, a three-electrode system is constructed in an electrolytic cell, an alkaline solution is added into the electrolytic cell as electrolyte, and the working electrode is immersed into the electrolyte to carry out carbon dioxide electrochemical reduction reaction.
The catalyst prepared by the method has the optimal selective regulation and control effect on the ethylene and the carbon monoxide, can obviously change the proportion of the two in the product, and obviously enhances the catalytic activity. The working potential of electrochemical carbon dioxide reduction is-1.2 to-1.6V vs. RHE, and typical working electrode potentials comprise-1.2V, -1.25V, -1.3V, -1.35V, -1.4V, -1.45V, -1.5V, -1.55V, -1.6V and the like, and the potentials are RHE. If the working potential is too low, the transfer speed of the driving electrons is low, the electrons are not transferred yet, and the intermediate falls off from the surface of the catalyst; if the working potential is too high, the occurrence of hydrogen evolution reaction is aggravated, and the conversion of carbon dioxide into carbon-containing products is affected.
The technical effects of the present invention will be described below with reference to specific examples.
Example 1
(1) 2.75mmol of copper nitrate and 0.25mmol of cadmium nitrate are weighed and dissolved in 100mL of deionized water, and stirred until a clear solution is formed;
(2) 50mL of 3M sodium carbonate solution is added into the solution and fully stirred for 2h to form flocculent precipitate;
(3) Placing the precipitate in a crucible, performing pyrolysis treatment under an air atmosphere, heating a muffle furnace at a speed of 5 ℃/min, pyrolyzing at 600 ℃ for 2 hours, and naturally cooling;
(4) KHCO at cathode 0.1M 3 The anode is in 0.05M H2SO4 solution, the product obtained in the step (3) is used as a working electrode, a platinum net is used as a counter electrode, a silver/silver chloride electrode is used as a reference electrode, and the area of the electrode immersed in the electrolyte is 1 x 1cm 2 The electrolysis was continued for 1h at-1.0V vs. RHE, -1.1V vs. RHE, -1.2V vs. RHE, -1.3V vs. RHE, -1.4V vs. RHE, -1.5V vs. RHE, collecting the gas product and testing the current-time curves at different operating potentials.
The results of testing gaseous products at different operating potentials as shown in fig. 1-6 show that the higher the applied voltage, the higher the current density, the more abundant the gaseous products, and the gradual appearance of C2 products, and when the operating voltage exceeds-1.3V, the hydrogen evolution reaction is significantly exacerbated, resulting in a decrease in CO2 conversion. The three-electrode system which is the same as the three-electrode system in the step (4) is adopted, CO2 reduction energy efficiency, yield, faraday efficiency, electrochemical impedance and the like are tested in 25mL of 0.1M KHCO3 electrolyte under the working potential of-1.2V vs. RHE, and the test result shows that the catalyst has good ethylene product selectivity, faraday efficiency reaches 55% under-1.2V, and the energy efficiency is close to 30%.
Example 2
(1) 2.625mmol of copper nitrate and 0.375mmol of cadmium nitrate are weighed and dissolved in 100mL of deionized water, and stirred until a clear solution is formed;
(2) 50mL of 3M sodium carbonate solution is added into the solution and fully stirred for 2h to form flocculent precipitate;
(3) Placing the precipitate in a crucible, performing pyrolysis treatment under an air atmosphere, heating a muffle furnace at a speed of 5 ℃/min, pyrolyzing at 600 ℃ for 2 hours, and naturally cooling;
(4) KHCO at cathode 0.1M 3 The anode is in 0.05M H2SO4 solution, the product obtained in the step (3) is used as a working electrode, a platinum net is used as a counter electrode, a silver/silver chloride electrode is used as a reference electrode, and the electrode area of the working electrode immersed in the electrolyte is 1*1cm 2 Continuously electrolyzing for 1h under-1.0V vs. RHE, -1.1V vs. RHE, -1.2V vs. RHE, -1.3V vs. RHE, -1.4V vs. RHE and-1.5V vs. RHE, and collecting a gas product; current versus time curves were tested at different operating potentials.
The results of testing the gaseous products at different operating potentials are shown in fig. 1-6, and the results show that the higher the applied voltage is, the higher the current density is, the more the gaseous products are rich, the C2 products gradually appear, and when the operating voltage exceeds-1.2V, the hydrogen evolution reaction is obviously aggravated, so that the CO2 conversion rate is reduced. CO was tested at an operating potential of-1.2V vs. RHE in 25mL of 0.1M KHCO3 electrolyte using the same three electrode system as (4) 2 The catalyst has good ethylene product selectivity, faraday efficiency reaching 33% at-1.2V and energy efficiency reaching 13.7%.
Example 3
(1) 2.875mmol of copper nitrate and 0.125mmol of cadmium nitrate are weighed and dissolved in 100mL of deionized water, and stirred until a clear solution is formed;
(2) 50mL of 3M sodium carbonate solution is added into the solution and fully stirred for 2h to form flocculent precipitate;
(3) Placing the precipitate in a crucible, performing pyrolysis treatment under an air atmosphere, heating a muffle furnace at a speed of 5 ℃/min, pyrolyzing at 600 ℃ for 2 hours, and naturally cooling;
(4) KHCO at cathode 0.1M 3 The anode is in 0.05M H2SO4 solution, the product obtained in the step (3) is used as a working electrode, a platinum net is used as a counter electrode, a silver/silver chloride electrode is used as a reference electrode, and the area of the electrode immersed in the electrolyte is 1 x 1cm 2 Continuously electrolyzing for 1h under-1.0V vs. RHE, -1.1V vs. RHE, -1.2V vs. RHE, -1.3V vs. RHE, -1.4V vs. RHE and-1.5V vs. RHE, and collecting a gas product; current versus time curves were tested at different operating potentials.
The results of testing the gaseous products at different operating potentials are shown in figures 1-6, and the results show that the higher the applied voltage, the higher the current density, the richer the gaseous products, and the C2 products are gradually appeared, when workingAfter the operating voltage exceeds-1.2V, the hydrogen evolution reaction is obviously aggravated, resulting in a decrease in CO2 conversion. CO was tested at an operating potential of-1.3V vs. RHE in 25mL of 0.1M KHCO3 electrolyte using the same three electrode system as (4) 2 The catalyst has good ethylene product selectivity, faraday efficiency reaching 38% at-1.2V and energy efficiency reaching 16.2%.
Comparative example 1
(1) Weighing 3mmol of copper nitrate, dissolving in 100mL of deionized water, and stirring to form a clear solution;
(2) Placing the precipitate in a crucible, performing pyrolysis treatment under an air atmosphere, heating a muffle furnace at a speed of 5 ℃/min, pyrolyzing at 600 ℃ for 2 hours, and naturally cooling;
(3) Placing the precipitate in a crucible, performing pyrolysis treatment under an air atmosphere, heating a muffle furnace at a speed of 5 ℃/min, pyrolyzing at 600 ℃ for 2 hours, and naturally cooling;
(4) KHCO at cathode 0.1M 3 The anode is in 0.05M H2SO4 solution, the product obtained in the step (3) is used as a working electrode, a platinum net is used as a counter electrode, a silver/silver chloride electrode is used as a reference electrode, and the area of the electrode immersed in the electrolyte is 1 x 1cm 2 The electrolysis was continued for 1h at-1.0V vs. RHE, -1.1V vs. RHE, -1.2V vs. RHE, -1.3V vs. RHE, -1.4V vs. RHE, -1.5V vs. RHE, and the gaseous product was collected. Current versus time curves were tested at different operating potentials.
The results of testing the gas products at different operating potentials are shown in fig. 1-6, and the results show that the higher the applied voltage is, the higher the current density is, the more the gas phase products are, and when the operating voltage exceeds-1.3V, the hydrogen evolution reaction is obviously aggravated, so that the CO2 conversion rate is reduced. CO was tested at an operating potential of-1.3V vs. RHE in 25mL of 0.1MKHCO3 electrolyte using the same three electrode system as (4) 2 The test results show that the catalyst has good ethylene product selectivity, faraday efficiency, 23% of Faraday efficiency of ethylene product under-1.3V and energy efficiency of9.8%。
Comparative example 2
(1) Weighing 3mmol of cadmium nitrate, dissolving in 100mL of deionized water, and stirring to form a clear solution;
(2) Placing the precipitate in a crucible, performing pyrolysis treatment under an air atmosphere, heating a muffle furnace at a speed of 5 ℃/min, pyrolyzing at 600 ℃ for 2 hours, and naturally cooling;
(3) Placing the precipitate in a crucible, performing pyrolysis treatment under an air atmosphere, heating a muffle furnace at a speed of 5 ℃/min, pyrolyzing at 600 ℃ for 2 hours, and naturally cooling;
(4) KHCO at cathode 0.1M 3 The anode is in 0.05M H2SO4 solution, the product obtained in the step (3) is used as a working electrode, a platinum net is used as a counter electrode, a silver/silver chloride electrode is used as a reference electrode, and the area of the electrode immersed in the electrolyte is 1 x 1cm 2 The electrolysis was continued for 1h at-1.0V vs. RHE, -1.1V vs. RHE, -1.2V vs. RHE, -1.3V vs. RHE, -1.4V vs. RHE, -1.5V vs. RHE, and the gaseous product was collected. Current versus time curves were tested at different operating potentials.
The results of testing the gas products at different operating potentials are shown in fig. 1-6, and the results show that the higher the applied voltage is, the higher the current density is, the more the gas phase products are, and when the operating voltage exceeds-1.3V, the hydrogen evolution reaction is obviously aggravated, so that the CO2 conversion rate is reduced. CO was tested at an operating potential of-1.3V vs. RHE in 25mL of 0.1MKHCO3 electrolyte using the same three electrode system as (4) 2 The test results show that the catalyst has good ethylene product selectivity, faraday efficiency, carbon monoxide product Faraday efficiency reaching 88% under-1.1V and no ethylene generation.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (10)

1. A method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide, characterized in that the method specifically comprises the following steps:
s1, dissolving metal salt into a metal salt solution;
s2, carrying out chemical precipitation on the metal salt solution in an air-exposed environment;
s3, carrying out pyrolysis treatment on the precipitated sediment in an air atmosphere to obtain a catalyst;
s4, placing the catalyst obtained in the step S3 on an electrode support for electrocatalytic treatment, so that the catalyst surface of the working electrode is subjected to carbon dioxide electrochemical reduction reaction in an electrolyte solution of an H-type electrolytic cell, and the middle of the H-type electrolytic cell is separated into a cathode and an anode by an exchange membrane.
2. The method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide according to claim 1, wherein any two of copper, cadmium, iron, nickel, bismuth and cobalt are selected as the metal salt component in the step S1, and the concentration of the metal salt is 1-1500 mM.
3. The method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide according to claim 1, wherein the chemical precipitant in step S2 is one or more of sodium carbonate, sodium bicarbonate, ammonium bicarbonate, potassium carbonate, and potassium bicarbonate; the time of chemical precipitation is 1-48 h.
4. The method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide as set forth in claim 1, wherein the specific operation of step S3 is: and (3) putting the precipitate into a muffle furnace, continuously introducing air, heating to a set temperature, and then preserving heat, wherein the temperature of pyrolysis treatment is 200-1000 ℃, the heating rate of pyrolysis treatment is 1-10 ℃/min, and the heat preservation time is 1-6 h.
5. The method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide as set forth in claim 1, wherein the specific operation of step S4 is: preparing the pyrolyzed catalyst into catalyst ink, and uniformly attaching the catalyst ink to the surface of an electrode support to serve as a working electrode; the counter electrode and the reference electrode are arranged to form a three-electrode system, the middle of the cathode and the anode of the H-type electrolytic cell is separated by an exchange membrane, and the working electrode carries out carbon dioxide electrochemical reduction reaction in electrolyte solution.
6. The method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide as claimed in claim 5, wherein in the step S4, the working electrode and the reference electrode are disposed at the cathode and the counter electrode is disposed at the anode during electrochemical reduction of carbon dioxide; the products of electrochemical reduction of carbon dioxide include one or more of formic acid, carbon monoxide, methane and ethylene.
7. The method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide as claimed in claim 6, wherein in the step S4, the counter electrode is one of a platinum sheet, a graphite rod, a platinum wire and a platinum mesh; the reference electrode adopts one of mercury/oxidized mercury, silver/silver chloride and saturated calomel electrode; the electrolyte solution adopts one or more of potassium bicarbonate, potassium hydroxide, sodium sulfate and potassium sulfate; the exchange membrane adopts one of a proton exchange membrane, an anion exchange membrane or a cation exchange membrane.
8. The method for producing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide as claimed in claim 7, wherein the electrolyte solution is potassium bicarbonate and the concentration of potassium bicarbonate is 0.05 to 2.5M.
9. The method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide according to claim 1 or 5, wherein in step S4, the electrode support is made of one of carbon paper, carbon cloth, carbon felt, glassy carbon electrode, copper foam and nickel foam.
10. The method for preparing a bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide according to claim 1 or 5, wherein in the step S4, electrochemical reduction of carbon dioxide adopts potentiostatic reduction, the electrochemical reduction working potential of carbon dioxide is-1.2V to-1.6V vs. rhe, and the duration of surface carbon dioxide reduction is 0.1h to 4h.
CN202311589549.4A 2023-11-27 2023-11-27 Preparation method of bimetallic oxide catalyst for selective electrochemical reduction of carbon dioxide Pending CN117626343A (en)

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