A basic copper carbonate gallium composite oxide and a preparation method and application thereof
The basic copper carbonate gallium-supported composite oxide catalyst was prepared by hydrothermal method, which solved the problem of narrow potential range of Cu-based catalysts and achieved stable generation of syngas over a wide potential range, with efficient CO/H2 ratio adjustment capability.
Patent Information
- Application Number
- CN202510439380.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2045-04-09
AI Technical Summary
Existing Cu-based catalysts have a narrow potential range in the process of CO2 electroreduction to produce syngas, which makes it impossible to stably generate syngas in scenarios with large potential fluctuations in renewable energy sources, thus affecting product selectivity.
A basic copper carbonate gallium-supported composite oxide catalyst was prepared by a hydrothermal method. By controlling the molar ratio of gallium nitrate and copper nitrate and the hydrothermal reaction conditions, a catalyst with an ultra-wide potential range was prepared for the electroreduction of CO2 to produce syngas.
It achieves stable synthesis gas generation within an ultra-wide potential range of -0.6 to -1.8V, with an adjustable CO/H2 ratio and a synthesis gas efficiency exceeding 90%, making it suitable for industrial applications.
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Figure CN120099580B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of catalyst preparation, specifically to a basic copper carbonate gallium-supported composite oxide and its preparation method, and its application in the electroreduction of CO2 to prepare syngas. Background Technology
[0002] Syngas (CO, H2) is widely used in the preparation of chemicals, fertilizers, fuels, and solvents, and is an important chemical feedstock and intermediate. The CO / H2 molar ratio is generally between 0.33 and 2. Syngas with different CO / H2 molar ratios can be used in specific chemical reaction processes to synthesize downstream products. For example, when the CO / H2 molar ratio is 0.3 to 0.5, it can be used to synthesize methane and methanol; when the CO / H2 molar ratio is 0.5 to 1, it can be used for Fischer-Tropsch product synthesis. Currently, syngas is mainly produced through the gasification of solid fuels such as coal or coke and light hydrocarbons such as natural gas and naphtha. The CO2 electroreduction reaction is driven by renewable energy and operates under normal temperature and pressure conditions, representing a potentially huge and sustainable energy conversion method.
[0003] The electroreduction of CO2 to syngas requires simultaneous control of the CO2 electroreduction rate and the hydrogen evolution reaction rate. Therefore, it is necessary to optimize the catalyst structure to possess suitable active sites for synergistic syngas production. Cu-based catalysts are widely used in CO2 electroreduction syngas production systems due to their moderate adsorption energies for C1 and C2 intermediates. However, most current Cu-based catalysts have relatively narrow potential ranges for syngas production. Fuel 2025,392,134821; J. Power Sources (2022, 535, 231453), but in application scenarios, the potential range of renewable energy often fluctuates greatly, directly affecting the product selectivity of the catalyst. Therefore, preparing a Cu-based catalyst system that can stably generate syngas over an ultrawide potential range can promote the industrialization of CO2 electroreduction reaction to produce syngas. Summary of the Invention
[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for preparing basic copper carbonate gallium-supported composite oxide and its application in the electroreduction of CO2 to prepare syngas, which addresses the shortcomings of the existing technology.
[0005] To solve the above-mentioned technical problems, the present invention discloses the following technical solution:
[0006] In a first aspect, the present invention discloses a basic copper carbonate gallium-supported composite oxide and its preparation method.
[0007] In the preparation method, water is used as a solvent, gallium nitrate and copper nitrate are used as gallium source and copper source, respectively, and urea is used as alkali source.
[0008] Specifically, the preparation method of the basic copper carbonate gallium-supported composite oxide includes dissolving gallium nitrate, copper nitrate and urea in water, sonicating and stirring to mix evenly, and performing a hydrothermal reaction to obtain a reaction solution containing the basic copper carbonate gallium-supported composite oxide; cooling the obtained reaction solution to room temperature, washing it thoroughly with deionized water, centrifuging it, and drying it at 60~80℃ for 18~24 hours to obtain the basic copper carbonate gallium-supported composite oxide.
[0009] The molar ratio of gallium nitrate to copper nitrate is 1:20 to 1:1.
[0010] The molar ratio of copper nitrate to urea is 1:2 to 8, such as 1:4 to 6.
[0011] The concentration of copper nitrate in the mixed solution is 0.085~0.145 mmol / mL, such as 0.095~0.125 mmol / mL.
[0012] The ultrasound refers to ultrasound until complete dissolution, such as ultrasound for 30-60 minutes.
[0013] The stirring is described as stirring until the mixture is homogeneous, such as stirring for 0.5 to 1 hour.
[0014] The temperature of the hydrothermal reaction is 110~120℃.
[0015] The hydrothermal reaction takes 18 to 24 hours.
[0016] Secondly, this invention discloses the application of the above-mentioned basic copper carbonate gallium-supported composite oxide in the catalytic electroreduction of CO2 to prepare syngas.
[0017] Specifically, the application involves fabricating an electrode from the basic copper carbonate gallium-supported composite oxide, which is used for the electrocatalytic reduction of CO2 to produce syngas.
[0018] In this process, an ink containing the basic copper carbonate gallium-loaded composite oxide, electrolyte, and solvent is dispersed on an electrode substrate and dried to obtain an electrode.
[0019] The electrolyte includes a Nafion solution, such as a 5% Nafion solution; the solvent includes isopropanol; the electrode substrate includes carbon paper; the ratio of the basic copper carbonate gallium-supported composite oxide, the electrolyte, and the solvent is 8~12 mg: 15~25 uL: 800~1200 uL, such as 10 mg: 18~22 uL: 900~1100 uL.
[0020] The catalyst loading in the electrode is 0.5~1.5 mg / cm³. 2Electrode substrate, such as 1 mg / cm 2 Electrode substrate.
[0021] In this H-type electrolytic cell three-electrode system, the electrode described above serves as the working electrode, while a platinum sheet acts as the counter electrode and a saturated silver chloride electrode serves as the reference electrode for the electrocatalytic reduction of CO2 to produce syngas. Furthermore, a potentiostatic method is employed, achieving a maximum current density of 50 mA / cm². 2 .
[0022] In the electrocatalysis, 0.05-0.2 M KHCO3 is used as the electrolyte, the CO2 flow rate is 18-22 sccm, and the electrolysis time is 55-65 min.
[0023] Among them, the stable potential for preparing syngas by electroreduction is relatively wide, ranging from -0.6 to -1.8 V.
[0024] Beneficial effects
[0025] 1. The method provided by the present invention has the advantages of simple preparation process, good repeatability, and convenient batch synthesis of composite oxide catalysts. Moreover, the catalyst has an ultra-wide stable potential range during the electroreduction preparation of syngas, with a stable potential range of -0.6 to -1.8V, and can stably adjust the CO / H2 ratio.
[0026] 2. This invention prepares a basic copper carbonate gallium-supported composite oxide, which is used to produce syngas by CO2 electroreduction with an efficiency of over 90%. This catalyst is expected to be widely used in the field of electrocatalysis. Attached Figure Description
[0027] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.
[0028] Figure 1 This is an X-ray diffraction pattern of the basic copper carbonate gallium-supported composite oxide prepared in Example 1 of this invention.
[0029] Figure 2 This is a transmission electron microscope (TEM) image of the basic copper carbonate gallium-supported composite oxide prepared in Example 1 of this invention.
[0030] Figure 3 This is a diagram showing the synthesis gas efficiency and proportion of the basic copper carbonate gallium-supported composite oxide prepared in Example 1 of this invention.
[0031] Figure 4 This is the X-ray diffraction pattern of the basic copper carbonate gallium-supported composite oxide prepared in Example 2 of this invention. Detailed Implementation
[0032] The present invention can be better understood from the following embodiments. However, those skilled in the art will readily understand that the descriptions in the embodiments are for illustrative purposes only and should not, and will not, limit the invention as detailed in the claims.
[0033] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are commercially available.
[0034] The following examples provide a method for preparing basic copper carbonate gallium-supported composite oxide. This method can rapidly synthesize large quantities of syngas with good dispersibility, high reproducibility, and stable proportions by electroreduction over a wide range of gallium to copper molar ratios using a simple hydrothermal process.
[0035] Example 1
[0036] 5 mmol of gallium nitrate, 5 mmol of copper nitrate, and 25 mmol of urea were added to 40 mL of water and sonicated until completely dissolved. The mixture was then stirred thoroughly for 1 hour until completely homogeneous. The resulting solution was transferred to a 50 mL stainless steel reactor lined with polytetrafluoroethylene and placed in a forced-air drying oven for hydrothermal reaction at 110 °C for 24 hours. After natural cooling to room temperature, the resulting precipitate was thoroughly washed with deionized water, centrifuged, and dried in an oven at 60 °C for 24 hours to obtain basic copper carbonate gallium-supported composite oxide. The X-ray diffraction pattern of the basic copper carbonate gallium-supported composite oxide is shown in [Figure number missing]. Figure 1 The positions and intensities of the diffraction peaks are consistent with those of the basic copper carbonate standard card (JCPDS 41-1390) and gallium hydroxide (JCPDS 54-0910). Its high-magnification transmission electron microscope image is shown below. Figure 2 The lattice stripe d=0.302 corresponds to the (230) crystal plane of basic copper carbonate, and the lattice stripe d=0.254 corresponds to the (021) crystal plane of gallium hydroxide.
[0037] Evaluation of CO2 electroreduction reaction: 10 mg of basic copper carbonate gallium-supported composite oxide catalyst was added to 20 μL of 5% Nafion solution and 1000 μL of isopropanol to prepare an ink solution. The solution was ultrasonically dispersed for 30 minutes. 25 μL of the ink solution was then dispersed in a 0.25 cm⁻¹ medium. 2 On the carbon paper, the catalyst loading is approximately 1 mg / cm³. 2 The electrode was dried under an infrared lamp for 10 min and used as the working electrode. The test was conducted using a potentiostatic method in a three-electrode system of an H-type electrolytic cell (using a platinum sheet as the counter electrode, a saturated silver chloride electrode as the reference electrode, and the working electrode), with a maximum current density of 50 mA / cm². 2The CO2 flow rate was 20 sccm, the electrolyte was 0.1 M KHCO3, and the electrolysis time was 60 min. Gaseous products were detected by gas chromatography, and liquid products were detected by liquid NMR. The entire electrochemical reaction process was monitored by applying voltage and recording current-time curves using an electrochemical workstation. The catalytic results are shown in […]. Figure 3 Stable syngas is generated between -0.8 and -1.8V, with a CO / H2 ratio of 0.15 to 0.37. The syngas efficiency exceeds 90% between -0.6 and -1.4V.
[0038] The methods for preparing syngas in the following embodiments and comparative examples are the same as those in this application, except that the basic copper carbonate gallium-supported composite oxide catalyst in the working electrode is replaced with the catalysts in the embodiments and comparative examples.
[0039] Example 2
[0040] 0.5 mmol of gallium nitrate, 5 mmol of copper nitrate, and 25 mmol of urea were added to 40 mL of water and sonicated until completely dissolved. The mixture was then stirred thoroughly for 1 hour until completely homogeneous. The resulting solution was transferred to a 50 mL stainless steel reactor lined with polytetrafluoroethylene and placed in a forced-air drying oven for hydrothermal reaction at 110 °C for 24 hours. After natural cooling to room temperature, the resulting precipitate was thoroughly washed with deionized water, centrifuged, and dried in an oven at 60 °C for 24 hours to obtain the basic copper carbonate gallium-supported catalyst. The X-ray diffraction pattern of the basic copper carbonate gallium-supported catalyst is shown below. Figure 4 Due to the low gallium content, no characteristic gallium signal was observed in the spectrum. Stable synthesis gas was generated between -0.6 and -1.8 V, with a CO / H2 ratio of 0.92 to 2.1.
[0041] Example 3
[0042] 0.25 mmol of gallium nitrate, 5 mmol of copper nitrate, and 25 mmol of urea were added to 40 mL of water and sonicated until completely dissolved. The mixture was then stirred thoroughly for 1 hour until completely homogeneous. The resulting solution was transferred to a 50 mL stainless steel reactor lined with polytetrafluoroethylene and placed in a forced-air drying oven for hydrothermal reaction at 110 °C for 24 hours. After natural cooling to room temperature, the resulting precipitate was thoroughly washed with deionized water, centrifuged, and dried in an oven at 60 °C for 24 hours to obtain the basic copper carbonate gallium-supported catalyst. Stable synthesis gas was generated between -0.6 and -1.8 V, with a CO / H2 ratio of 0.93–1.78.
[0043] Example 4
[0044] 1 mmol of gallium nitrate, 5 mmol of copper nitrate, and 25 mmol of urea were added to 40 mL of water and sonicated until completely dissolved. The mixture was then stirred thoroughly for 1 hour until completely homogeneous. The resulting solution was transferred to a 50 mL stainless steel reactor lined with polytetrafluoroethylene and placed in a forced-air drying oven for hydrothermal reaction at 110 °C for 24 hours. After natural cooling to room temperature, the resulting precipitate was thoroughly washed with deionized water, centrifuged, and dried in an oven at 60 °C for 24 hours to obtain the basic copper carbonate gallium-supported catalyst. Stable synthesis gas was generated between -0.6 and -1.8 V, with a CO / H2 ratio of 0.47–1.23.
[0045] As can be seen, this invention provides a basic copper carbonate gallium-supported composite oxide catalyst capable of electroreducing syngas with a stable proportion over an ultrawide potential range. Specifically, by adjusting the molar ratio of gallium and copper, this invention yields a basic copper carbonate gallium-supported composite oxide with an adjustable syngas proportion. This synthesis method is simple, low-cost, produces products with relatively uniform morphology and size, can be synthesized in large quantities, and exhibits good reproducibility. The basic copper carbonate gallium-supported composite oxide synthesized by this method can generate a stable proportion of syngas in an ultrawide potential range of -0.6 to -1.8 V during the CO2 electroreduction reaction.
[0046] Comparative Example 1
[0047] 5 mmol of copper nitrate and 25 mmol of urea were added to 40 mL of water and sonicated until completely dissolved. The mixture was then stirred thoroughly for 1 hour until completely homogeneous. The resulting solution was transferred to a 50 mL stainless steel reactor lined with polytetrafluoroethylene and placed in a forced-air drying oven for hydrothermal reaction at 110 °C for 24 hours. After natural cooling to room temperature, the resulting precipitate was thoroughly washed with deionized water, centrifuged, and dried in an oven at 60 °C for 24 hours to obtain the basic copper carbonate catalyst. Stable synthesis gas was generated between -0.6 and -1.8 V, with a CO / H2 ratio of 0.50–0.69.
[0048] Comparative Example 2
[0049] 5 mmol of zinc nitrate, 5 mmol of copper nitrate, and 25 mmol of urea were added to 40 mL of water and sonicated until completely dissolved. The mixture was then stirred thoroughly for 1 hour until completely homogeneous. The resulting solution was transferred to a 50 mL stainless steel reactor lined with polytetrafluoroethylene and placed in a forced-air drying oven for hydrothermal reaction at 110 °C for 24 hours. After natural cooling to room temperature, the resulting precipitate was thoroughly washed with deionized water, centrifuged, and dried in an oven at 60 °C for 24 hours to obtain the copper-zinc composite catalyst. Its application in syngas preparation yielded results shown in Table 1.
[0050] Table 1
[0051]
[0052] Comparative Example 3
[0053] 10 mmol of aluminum nitrate, 5 mmol of copper nitrate, and 30 mmol of urea were added to 40 mL of water and sonicated until completely dissolved. The mixture was then stirred thoroughly for 1 hour until completely homogeneous. The resulting solution was transferred to a 50 mL stainless steel reactor lined with polytetrafluoroethylene and placed in a forced-air drying oven for hydrothermal reaction at 110 °C for 24 hours. After natural cooling to room temperature, the resulting precipitate was thoroughly washed with deionized water, centrifuged, and dried in an oven at 60 °C for 24 hours to obtain the copper-aluminum composite catalyst. When used for syngas preparation, it exhibited a stable potential range of -0.9 to -1.2 V and a CO / H₂ ratio of 2.56 to 4.72.
[0054] It is evident that while basic copper carbonate catalysts offer an extremely wide potential range for syngas generation, they cannot regulate the CO / H2 ratio. Although copper-zinc and copper-aluminum composite catalysts can adjust the CO / H2 ratio, their stable potential ranges are relatively narrow. Due to frequent and significant fluctuations in the potential range during application, the CO / H2 ratio also fluctuates considerably, resulting in unstable production. Consequently, the syngas obtained is difficult to directly use for the preparation of corresponding products.
[0055] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.
Claims
1. A method for preparing basic copper carbonate gallium-supported composite oxide, characterized in that, A hydrothermal reaction was carried out on a mixed solution containing copper nitrate, gallium nitrate and urea to obtain basic copper carbonate gallium-loaded composite oxide.
2. The preparation method according to claim 1, characterized in that, The molar ratio of copper nitrate to gallium nitrate is 1:20 to 1:
1.
3. The preparation method according to claim 1, characterized in that, The molar ratio of copper nitrate to urea is 1:2~8.
4. The preparation method according to claim 1, characterized in that, The solvent of the mixed solution is water; the concentration of copper nitrate in the mixed solution is 0.085~0.145 mmol / mL.
5. The preparation method according to claim 1, characterized in that, The hydrothermal reaction temperature is 110~120℃, and the hydrothermal reaction time is 18~24h.
6. A basic copper carbonate gallium-supported composite oxide, characterized in that, Made by any one of claims 1 to 5.
7. An electrode, characterized in that, It is made from the basic copper carbonate gallium-supported composite oxide as described in claim 6.
8. The electrode according to claim 7, characterized in that, The ink containing the basic copper carbonate gallium-loaded composite oxide, electrolyte, and solvent is dispersed on the electrode substrate and dried to obtain the electrode.
9. The application of the electrode according to claim 7 or 8 in the electrocatalytic reduction of CO2 to prepare syngas.
10. The application according to claim 9, characterized in that, The potential for CO2 electroreduction to prepare syngas is -0.6 to -1.8 V.