Copper-based catalyst, preparation method and application of copper-based catalyst in preparation of methanol from carbon dioxide

Abstract

The invention belongs to the technical field of chemical synthesis catalysts, and particularly relates to a copper-based catalyst, a preparation method and application of the copper-based catalyst to preparation of methanol from carbon dioxide. The invention provides a copper-based catalyst, also provides a preparation method of the copper-based catalyst, and also provides application of the copper-based catalyst or the copper-based catalyst obtained by the preparation method in preparation of methanol from carbon dioxide. In the application, by optimizing the composition of the copper-based catalyst and adopting a distributed precipitation method in the preparation process, the anti-sintering performance and activity of the catalyst are effectively improved, and the dispersity of copper in the catalyst is further improved through secondary heat treatment after dispersion; a catalytic reaction test shows that the prepared catalyst is low in methanol selectivity and better in carbon dioxide conversion rate than a control group, and the technical defects that in the prior art, a copper-based catalyst for preparing methanol through carbon dioxide hydrogenation is low in methanol selectivity, low in carbon dioxide conversion rate and poor in stability are overcome.

Description

Technical Field

[0001] This application belongs to the field of chemical synthesis catalyst technology, and particularly relates to a copper-based catalyst, its preparation method, and its application in the production of methanol from carbon dioxide. Background Technology

[0002] The "dual carbon" goals of peak carbon emissions and carbon neutrality signify China's determination to promote high-quality economic development, social prosperity, and ecological environmental protection. Among these, carbon dioxide capture, utilization, and storage technologies can effectively control CO2 emissions. Specifically, this refers to the process of converting CO2 into high-value chemicals and fuels. This process has a significant and direct CO2 emission reduction effect, hence the catalytic conversion of carbon dioxide into methanol has attracted much attention from the scientific and industrial communities.

[0003] Copper-based catalysts for the hydrogenation of carbon dioxide to methanol mainly consist of catalysts modified with copper, zinc, aluminum, and other additives. Their activity is primarily related to the synergistic effect of copper and zinc, i.e., the contact area between them, and is also significantly influenced by the oxygen vacancies on the support. Current technologies, through the addition of additives and improvements in preparation methods, have not significantly improved the catalyst activity or selectivity. These catalysts suffer from low CO2 conversion rates (<30%) and low methanol selectivity (<70%). Furthermore, the CO2 hydrogenation process generates a large amount of water, affecting the catalyst's stability.

[0004] Therefore, the development of a copper-based catalyst, its preparation method, and its application in the production of methanol from carbon dioxide is a pressing issue for those skilled in the art, aiming to address the technical shortcomings of existing copper-based catalysts for the hydrogenation of carbon dioxide to methanol, such as low methanol selectivity, low carbon dioxide conversion rate, and poor stability. Summary of the Invention

[0005] Therefore, it is necessary to address the technical shortcomings of copper-based catalysts used in the hydrogenation of carbon dioxide to methanol, such as low methanol selectivity, low carbon dioxide conversion rate, and poor stability, and to provide a copper-based catalyst, its preparation method, and its application in the production of methanol from carbon dioxide.

[0006] This application provides a copper-based catalyst, which includes an active component, a first auxiliary component, a second auxiliary component, and a third auxiliary component. The active component includes CuO, the first auxiliary component includes ZnO, the second auxiliary component includes any one or more of ZrO2, Al2O3, MnO2, CeO2, Ga2O3, BaO, and MgO, and the third auxiliary component includes SiO2.

[0007] In one embodiment, the copper-based catalyst comprises, by weight percentage: 20%–60% active component, 20%–50% first auxiliary component, 1%–20% second auxiliary component, and 0.5%–10% third auxiliary component.

[0008] In one embodiment, the copper-based catalyst comprises, by weight percentage: 30%–50% of the active component, 20%–40% of the first auxiliary component, 5%–15% of the second auxiliary component, and 1%–5% of the third auxiliary component.

[0009] In one embodiment, the third auxiliary component comprises neutral silica sol.

[0010] This application also provides a method for preparing a copper-based catalyst, the method comprising:

[0011] Step 1: After the second auxiliary component and the first mass part of the first auxiliary component are dissolved, they are co-precipitated with the precipitant in a parallel flow. After precipitation is completed, stirring is continued for a first preset time. The slurry is collected and then filtered, washed, dried, and calcined in sequence. It is then dispersed in water and ball-milled to obtain the first intermediate product. The third auxiliary component is mixed with nitric acid solution to obtain a third auxiliary component solution with a pH value of 4-5. The active component and the second mass part of the first auxiliary component nitrate are dissolved in deionized water and then mixed with the third auxiliary component solution to obtain the second intermediate product.

[0012] Step 2: The precipitant and the second intermediate product are co-precipitated into the first intermediate product in a parallel flow, and the first solid is collected by filtration;

[0013] Step 3: After the first solid is dispersed in an organic solvent, it is successively stirred, filtered, washed, dried and calcined. The resulting solid is then dispersed in water and ball-milled to obtain the third intermediate product.

[0014] Step 4: After the remaining first auxiliary component is dissolved, it is co-precipitated with the precipitant and the third intermediate product in a co-current flow. After precipitation is completed, stirring is continued, and the mixture is then filtered, washed, dried and calcined in sequence to obtain the copper-based catalyst.

[0015] The active component includes CuO, the first auxiliary component includes ZnO, the second auxiliary component includes any one or more of ZrO2, Al2O3, MnO2, CeO2, Ga2O3, BaO and MgO, and the third auxiliary component includes SiO2.

[0016] In one embodiment, based on the total mass percentage of the first auxiliary component being 100%, in step one, the first mass part is 10% to 20% and the second mass part is 30% to 60%.

[0017] In one embodiment, based on the total mass percentage of the first auxiliary agent component being 100%, in step one, the first mass part is 10% to 30% and the second mass part is 30% to 65%.

[0018] In one embodiment, in step one, the precipitant includes sodium carbonate solution and / or ammonia water, the temperature of the co-precipitation is 50-90°C, the time of the co-precipitation is 0.5-3 hours, and the pH of the co-precipitation is 6-8.

[0019] In step one, the first preset stirring time is 2 to 4 hours, the calcination temperature is 400 to 800°C, the calcination time is 2 to 8 hours, and the ball milling time is 2 to 30 minutes.

[0020] In one embodiment, in step one, the concentration of the sodium carbonate solution is 1 mol / L.

[0021] In one embodiment, in step one, the precipitant includes sodium carbonate solution and / or ammonia water, the temperature of the co-precipitation is 60-80°C, the time of the co-precipitation is 1-2 hours, and the pH of the co-precipitation is 6.5-7.5.

[0022] In step one, the first preset stirring time is 3 to 4 hours, the calcination temperature is 500 to 700°C, the calcination time is 3 to 6 hours, and the ball milling time is 5 to 10 minutes.

[0023] In one embodiment, in step one, the concentration of the nitric acid solution is 0.5 mol / L.

[0024] In one embodiment, in step two, the precipitant includes sodium carbonate solution and / or ammonia water, the temperature of the co-precipitation is 50-90°C, the time of the co-precipitation is 0.5-2 hours, and the pH of the co-precipitation is 6-8.

[0025] In one embodiment, in step two, the concentration of the sodium carbonate solution is 0.5 mol / L.

[0026] In one embodiment, in step two, the precipitant includes sodium carbonate solution and / or ammonia water, the temperature of the co-precipitation is 60-80°C, the time of the co-precipitation is 1-2 hours, and the pH of the co-precipitation is 6.5-7.5.

[0027] In one embodiment, in step three, the organic solvent includes any one or more of ethanol, propanol, n-butanol, and isobutanol; the stirring temperature is 50–90°C; the stirring time is 4–24 hours; the calcination temperature is 200–600°C; the calcination time is 2–8 hours; and the ball milling time is 2–30 minutes.

[0028] In one embodiment, in step three, the stirring temperature is 60-80°C, the stirring time is 6-18 hours, the calcination temperature is 400-600°C, the calcination time is 4-6 hours, and the ball milling time is 5-15 minutes.

[0029] In one embodiment, in step four, the precipitant includes sodium carbonate solution and / or ammonia water, the temperature of the co-precipitation is 40-60°C, the pH of the co-precipitation is 7-9, the stirring time is 4-8 hours, the calcination temperature is 400-600°C, and the calcination time is 2-6 hours.

[0030] In one embodiment, in step four, the concentration of the sodium carbonate solution is 0.5 mol / L.

[0031] In one embodiment, in step four, the precipitant includes sodium carbonate solution and / or ammonia water, the temperature of the co-precipitation is 50-60°C, the pH of the co-precipitation is 7-8, the stirring time is 6-8 hours, the calcination temperature is 500-600°C, and the calcination time is 4-6 hours.

[0032] In one embodiment, the preparation method further includes: step five, activation, wherein the activation method includes: the copper-based catalyst obtained in step four is reduced at 150°C to 300°C under a pressure of 0 to 1.0 MPa using a first H2 / N2 mixed gas with a hydrogen content of 5% to 20% for 4 to 48 hours; the reaction temperature is adjusted to 180 to 270°C and a second H2 / H2O / CH3OH / N2 mixed gas is introduced for 2 to 48 hours, wherein the ratio of H2 / H2O / CH3OH / N2 in the second mixed gas is (40 to 80%):(0 to 5%):(0 to 5%):(20 to 60%).

[0033] In one embodiment, nitrogen is the balance gas in the second mixed gas.

[0034] In one embodiment, the copper-based catalyst obtained in step four is reduced at 0.1–0.5 MPa and 200–300°C using a first H2 / N2 mixture with a hydrogen content of 10–15% for 6–24 hours; then the reaction temperature is adjusted to 150–250°C and treated with a second H2 / H2O / CH3OH / N2 mixture for 6–24 hours, wherein the ratio of H2 / H2O / CH3OH / N2 in the second mixture is (50–60%):(1–3%):(1–3%):(30–50%).

[0035] This application also provides the application of a copper-based catalyst comprising any one of the above-described copper-based catalysts or a copper-based catalyst prepared by any one of the above-described preparation methods in the production of methanol from carbon dioxide.

[0036] In one embodiment, the reaction pressure for producing methanol from carbon dioxide is 2–8 MPa, and the feed space velocity is 2000–20000 h⁻¹. -1 H2 / CO2 = 2 to 8.

[0037] In one embodiment, the reaction pressure for producing methanol from carbon dioxide is 4–6 MPa, and the feed space velocity is 3000–12000 h⁻¹. -1 H2 / CO2 = 3 to 6.

[0038] The copper-based catalyst, its preparation method, and its application in the production of methanol from carbon dioxide provided in this application have the following advantages:

[0039] 1. In the technical solution provided in the embodiments of this application, a stepwise precipitation method is used for precipitation, and by controlling the precipitation order of each component, the carrier structure and the distribution of active components are optimized. At the same time, the interaction and contact area between active components and additives are enhanced, thereby improving the activity of the catalyst.

[0040] 2. In the technical solution provided in the embodiments of this application, after the active component has precipitated, the intermediate product after precipitation is dispersed again in an organic alcohol medium for secondary heat treatment, which effectively improves the dispersion of copper.

[0041] 3. In the technical solution provided in the embodiments of this application, acidified silica sol is used, which can be completely and uniformly mixed with the metal solution. During the precipitation process, SiO2 is dispersed more uniformly, which is beneficial to improving the anti-sintering performance of the catalyst.

[0042] 4. In the technical solution provided in the embodiments of this application, the catalyst is activated in a mixed gas atmosphere containing H2 / H2O / CH3O / N2, which helps to form a copper-zinc alloy, improves the dispersion of copper, and also inhibits the sintering of copper, thereby improving the stability of the catalyst.

[0043] In summary, this application provides a copper-based catalyst, comprising: an active component, a first auxiliary component, a second auxiliary component, and a third auxiliary component. The active component comprises CuO, the first auxiliary component comprises ZnO, the second auxiliary component comprises any one or more of ZrO2, Al2O3, MnO2, CeO2, Ga2O3, BaO, and MgO, and the third auxiliary component comprises SiO2. This application also provides a method for preparing the copper-based catalyst, and provides an application of the above-mentioned copper-based catalyst or the copper-based catalyst obtained by the above preparation method in the production of methanol from carbon dioxide. In the technical solution provided by this application, by optimizing the composition of the copper-based catalyst and using a distributed precipitation method during the preparation process, the anti-sintering performance and activity of the catalyst are effectively improved, and the dispersion of copper in the catalyst is further improved through secondary heat treatment after dispersion. Furthermore, catalytic reaction testing shows that the prepared catalyst exhibits lower methanol selectivity and carbon dioxide conversion rate than the control group, solving the technical defects of low methanol selectivity, low carbon dioxide conversion rate, and poor stability in copper-based catalysts for the hydrogenation of carbon dioxide to methanol in the prior art. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0045] Figure 1 A schematic diagram of one process for preparing a copper-based catalyst in the technical solution provided in the embodiments of this application;

[0046] Figure 2 Another schematic diagram of a method for preparing a copper-based catalyst is provided in the technical solution of this application embodiment. Detailed Implementation

[0047] This application provides a copper-based catalyst, a preparation method, and its application in the production of methanol from carbon dioxide, to address the technical defects of copper-based catalysts for the production of methanol from carbon dioxide in the prior art, such as low methanol selectivity, low carbon dioxide conversion rate, and poor stability.

[0048] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0050] The following examples and comparative examples will be combined Figure 1 To prepare the catalyst.

[0051] Example 1

[0052] In this embodiment, the materials are fed according to the following mass percentages: active component CuO 50%, first auxiliary component ZnO 35%, second auxiliary component: Al2O 33% and ZrO 2 10%, and third auxiliary component SiO 2%. Each component is weighed with its corresponding metal nitrate, and the SiO 2 in the third auxiliary component is a neutral silica sol with a 30% SiO 2 content.

[0053] 15% of the first auxiliary agent precursor, zinc nitrate (the total amount of zinc nitrate added), and the second auxiliary agent precursors, aluminum nitrate and zirconium nitrate, were prepared into a 0.5 mol / L solution using deionized water. This solution was then co-precipitated with 1 mol / L Na₂CO₃ as a precipitant at 80°C under co-current flow. The pH was controlled at 7–8 during precipitation, and the precipitation time was 1 hour. After precipitation, the mixture was kept at the same temperature and stirring speed for another 4 hours. The resulting slurry was directly filtered, washed, dried, and calcined at 600°C for 8 hours. The calcined solid was dispersed in deionized water to prepare a 350 g / L slurry, which was then ground in a ball mill for 10 minutes to obtain the first intermediate product 1.

[0054] The neutral silica sol, the precursor of the third auxiliary agent, was prepared into a solution with a pH of 4 to 5 using 0.5 mol / L HNO3 solution.

[0055] The active component precursor copper nitrate and 60% of the first auxiliary agent precursor zinc nitrate (here, the total amount of zinc nitrate salt added) were prepared into a 0.5 mol / L aqueous solution with deionized water, and then mixed with the silica sol solution to obtain the second intermediate product 1.

[0056] The second intermediate product 1 was co-precipitated with a 0.5 mol / L Na₂CO₃ precipitant solution at 65°C into the first intermediate product. The precipitation time was controlled at 2 hours, and the pH during precipitation was 6–7. After precipitation, the mixture was filtered, washed, and the first solid 1 was collected.

[0057] The first solid 1 was dispersed in isobutanol to form a slurry of 200 g / L. The slurry was stirred at 80°C for 24 hours, filtered, washed, and dried, and then calcined at 400°C for 4 hours. The calcined solid was dispersed in deionized water and ground in a ball mill for 10 minutes. The resulting slurry was the third intermediate product 1.

[0058] The remaining 25% of the first auxiliary precursor, zinc nitrate (the total amount of zinc nitrate salt added here), was prepared into a 0.5 mol / L solution and co-precipitated with a 0.5 mol / L Na₂CO₃ precipitant in the third intermediate 1. The precipitation temperature was controlled at 60℃, pH = 8-9, and the precipitation time was 2 hours. After precipitation, stirring was continued for 6 hours, followed by filtration, washing, drying, and calcination at 400℃ for 2 hours. The second solid 1 was then collected.

[0059] Add 2% graphite to the second solid 1, granulate and compress it into tablets to obtain catalyst a1.

[0060] Example 2

[0061] In this embodiment, 10% ZrO2 was replaced with 10% MnO2, and the other aspects were the same as in Example 1. Catalyst a2 was obtained.

[0062] Example 3

[0063] In this embodiment, 10% ZrO2 was replaced with 10% MgO, and the other aspects were the same as in Example 1. Catalyst a3 was obtained.

[0064] Example 4

[0065] In this embodiment, 10% ZrO2 was replaced with 10% CeO2, and isobutanol was replaced with n-butanol; other aspects were the same as in Example 1. Catalyst a4 was obtained.

[0066] Example 5

[0067] In this embodiment, 3% Al2O3 was replaced with 3% Ga2O3, and isobutanol was replaced with ethanol; the other steps were the same as in Example 1. Catalyst a5 was obtained.

[0068] Example 6

[0069] In this embodiment, the feed amounts of the raw materials were modified to: 60% CuO, 25% ZnO, 3% Al2O3, 7% ZrO2, and 5% SiO2. Other aspects remained the same as in Example 1. Catalyst a6 was obtained.

[0070] Example 7

[0071] In this embodiment, the raw material feeding amounts were modified to: 50% CuO, 35% ZnO, 3% Al2O3, 5% ZrO2, and 2% SiO2, while other aspects remained the same as in Example 1. This resulted in the shaped catalyst a7.

[0072] Example 8

[0073] In this embodiment, the raw material feeding amounts were modified to: 30% CuO, 40% ZnO, 5% Al2O3, 5% ZrO2, 5% CeO2, and 10% SiO2. Other aspects remained the same as in Example 1. This resulted in the shaped catalyst a8.

[0074] Comparative Example 1

[0075] The preparation method was the same as in Example 1, except that a silica sol aqueous solution with pH=7 was used directly. Catalyst B1 was obtained.

[0076] Comparative Example 2

[0077] The preparation method is the same as in Example 1, except that tetraethyl orthosilicate solution is used instead of silica sol solution. Catalyst B2 is obtained.

[0078] Comparative Example 3

[0079] A 1 mol / L solution of the precursor metal nitrates of the four metal oxides was prepared using a ratio of 50% CuO, 35% ZnO, 3% Al2O3, and 10% ZrO2.

[0080] Neutral silica sol was prepared into a solution with pH = 4-5 by adding 2% SiO2 by weight. After thorough mixing, the solution was co-precipitated with a 1 mol / L sodium carbonate solution at 80°C for 2 hours, maintaining a pH of 7-8 during precipitation. After precipitation, the solution was aged for 4 hours at the same temperature and stirring speed. Then, it was filtered, washed, dried, and calcined at 400°C for 4 hours to obtain catalyst B3.

[0081] Comparative Example 4

[0082] Weigh out the corresponding metal nitrates according to the mass ratio of 50% CuO, 35% ZnO, 3% Al2O3, 10% ZrO2, and 2% SiO2. The SiO2 used is a neutral silica sol with a SiO2 content of 30%.

[0083] Copper nitrate and 60% zinc nitrate were prepared into a 0.5M aqueous solution using deionized water. The two solutions were mixed thoroughly and co-precipitated with 1 mol / L Na₂CO₃ at 80℃ in a co-current manner. The pH was controlled at 7–8 during precipitation, and the precipitation time was 1 hour. After precipitation, the mixture was kept at the same temperature and stirring speed for another 4 hours. The resulting slurry was directly filtered, washed, dried, and calcined at 600℃ for 8 hours. The calcined solid was dispersed in deionized water to prepare a 350 g / L slurry, which was then ground in a ball mill for 10 minutes. The first slurry was collected.

[0084] The silica sol was prepared into a solution with a pH of 4-5 using 0.5 mol / L HNO3 solution. 15% of this solution, containing zinc nitrate, aluminum nitrate, and zirconium nitrate, was prepared into a 0.5 M solution using deionized water. This solution was then co-precipitated with 0.5 mol / L Na2CO3 solution at 65°C in a parallel flow to the first slurry. The precipitation time was controlled at 2 hours, and the pH remained at 6-7 during precipitation. After precipitation, the solution was filtered, washed, and the solid was obtained. The solid was dispersed in isobutanol to form a 200 g / L slurry, stirred at 80°C for 24 hours, filtered, washed, and dried. The calcined solid was then calcined at 400°C for 4 hours. The calcined solid was dispersed in deionized water and ball-milled for 10 minutes to obtain the second slurry.

[0085] The remaining 25% of zinc nitrate was prepared into a 0.5 mol / L solution and co-precipitated with 0.5 mol / L Na₂CO₃ precipitant in the second slurry under co-current flow. The precipitation temperature was controlled at 60℃, pH = 8-9, and the precipitation time was 2 hours. After precipitation, stirring was continued for 6 hours, followed by filtration, washing, drying, calcination at 400℃ for 2 hours, and granulation and tableting with 2% graphite. Catalyst B4 was obtained.

[0086] Test case

[0087] This test example is a specific test example of the catalytic effect of catalysts a1-a8 prepared in Examples 1-8 and catalysts B1-B4 prepared in Comparative Examples 1-4 on the production of methanol from carbon dioxide.

[0088] In this test example, a fixed-bed reactor was evaluated using a catalyst with a catalyst loading of 100 ml. The catalyst was crushed to 2-3 mm before loading, and the upper and lower parts of the catalyst bed in the reactor were filled with 6 mm, 3 mm, and 1 mm ceramic balls, respectively.

[0089] Further reading is available here. Figure 2 Before the catalytic reaction, the catalyst is activated by reducing it with a 10% H2 / N2 mixture at 0.1 MPa and 250 °C for 6 hours, and then treating it for 4 hours under the same conditions in an atmosphere of H2 / H2O / CH3OH / N2 with a volume ratio of (50%:0.5%:0.5%:49%).

[0090] After activation treatment, the temperature was lowered to 220°C before feeding for reaction, with a space velocity of 5000 h⁻¹. -1 The pressure was 5 MPa, and the H2 / CO2 / N2 ratio was 71.5:23.5:5. Samples were taken for analysis after 24 hours of reaction.

[0091] The reaction results are shown in Table 1.

[0092] Table 1 Reaction performance results

[0093]

[0094]

[0095] As can be seen from Table 1, compared with the control group catalyst, the catalyst prepared by the technical solution provided in this application has better CO2 conversion rate and CH3OH selectivity than the control group, while the selectivity of by-products CO and CH4 is lower than that of the control group. This solves the technical defects of low CO2 conversion rate and low methanol selectivity in the existing CO2 hydrogenation to methanol catalyst.

[0096] From the above embodiments, it can be concluded that the technical solution provided by the embodiments of this application has the following advantages:

[0097] 1. In the technical solution provided in the embodiments of this application, a stepwise precipitation method is used for precipitation, and by controlling the precipitation order of each component, the carrier structure and the distribution of active components are optimized. At the same time, the interaction and contact area between active components and additives are enhanced, thereby improving the activity of the catalyst.

[0098] 2. In the technical solution provided in the embodiments of this application, after the active component has precipitated, the intermediate product after precipitation is dispersed again in an organic alcohol medium for secondary heat treatment, which effectively improves the dispersion of copper.

[0099] 3. In the technical solution provided in the embodiments of this application, acidified silica sol is used, which can be completely and uniformly mixed with the metal solution. During the precipitation process, SiO2 is dispersed more uniformly, which is beneficial to improving the anti-sintering performance of the catalyst.

[0100] 4. In the technical solution provided in the embodiments of this application, the catalyst is activated in a mixed gas atmosphere containing H2 / H2O / CH3O / N2, which helps to form a copper-zinc alloy, improves the dispersion of copper, and also inhibits the sintering of copper, thereby improving the stability of the catalyst.

[0101] In summary, this application provides a copper-based catalyst, comprising: an active component, a first auxiliary component, a second auxiliary component, and a third auxiliary component. The active component comprises CuO, the first auxiliary component comprises ZnO, the second auxiliary component comprises any one or more of ZrO2, Al2O3, MnO2, CeO2, Ga2O3, BaO, and MgO, and the third auxiliary component comprises SiO2. This application also provides a method for preparing the copper-based catalyst, and provides an application of the above-mentioned copper-based catalyst or the copper-based catalyst obtained by the above preparation method in the production of methanol from carbon dioxide. In the technical solution provided by this application, by optimizing the composition of the copper-based catalyst and using a distributed precipitation method during the preparation process, the anti-sintering performance and activity of the catalyst are effectively improved, and the dispersion of copper in the catalyst is further improved through secondary heat treatment after dispersion. Furthermore, catalytic reaction testing shows that the prepared catalyst exhibits lower methanol selectivity and carbon dioxide conversion rate than the control group, solving the technical defects of low methanol selectivity, low carbon dioxide conversion rate, and poor stability in copper-based catalysts for the hydrogenation of carbon dioxide to methanol in the prior art.

[0102] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. Furthermore, other implementation methods can be derived from the above embodiments, allowing for structural and logical substitutions and changes without departing from the scope of this disclosure.

[0103] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A copper-based catalyst, characterized in that, The copper-based catalyst comprises: an active component, a first auxiliary component, a second auxiliary component, and a third auxiliary component. The active component comprises CuO, the first auxiliary component comprises ZnO, the second auxiliary component comprises any one or more of ZrO2, Al2O3, MnO2, CeO2, Ga2O3, BaO, and MgO, and the third auxiliary component comprises SiO2.

2. The copper-based catalyst according to claim 1, characterized in that, The copper-based catalyst comprises, by mass percentage: 20%–60% of the active component, 20%–50% of the first auxiliary component, 1%–20% of the second auxiliary component, and 0.5%–10% of the third auxiliary component.

3. A method for preparing a copper-based catalyst, characterized in that, The preparation method includes: Step 1: After the second auxiliary component and the first mass part of the first auxiliary component are dissolved, they are co-precipitated with the precipitant in a parallel flow. After precipitation is completed, stirring is continued for a first preset time. The slurry is collected and then filtered, washed, dried, and calcined in sequence. It is then dispersed in water and ball-milled to obtain the first intermediate product. The third auxiliary component is mixed with nitric acid solution to obtain a third auxiliary component solution with a pH value of 4-5. The active component and the second mass part of the first auxiliary component nitrate are dissolved in deionized water and then mixed with the third auxiliary component solution to obtain the second intermediate product. Step 2: The precipitant and the second intermediate product are co-precipitated into the first intermediate product in a parallel flow, and the first solid is collected by filtration; Step 3: After the first solid is dispersed in an organic solvent, it is successively stirred, filtered, washed, dried and calcined. The resulting solid is then dispersed in water and ball-milled to obtain the third intermediate product. Step 4: After the remaining first auxiliary component is dissolved, it is co-precipitated with the precipitant and the third intermediate product in a co-current flow. After precipitation is completed, stirring is continued, and the mixture is then filtered, washed, dried and calcined in sequence to obtain the copper-based catalyst. The active component includes CuO, the first auxiliary component includes ZnO, the second auxiliary component includes any one or more of ZrO2, Al2O3, MnO2, CeO2, Ga2O3, BaO and MgO, and the third auxiliary component includes SiO2.

4. The preparation method according to claim 3, characterized in that, Based on mass parts, with the total mass percentage of the first auxiliary agent component being 100%, in step one, the first mass part is 10% to 20% and the second mass part is 30% to 60%.

5. The preparation method according to claim 3 or 4, characterized in that, In step one, the precipitant includes sodium carbonate solution and / or ammonia water, the temperature of the co-precipitation is 50-90°C, the time of the co-precipitation is 0.5-2 hours, and the pH value of the co-precipitation is 6-8. In step one, the first preset time is 2 to 4 hours, the calcination temperature is 400 to 800°C, the calcination time is 2 to 8 hours, and the ball milling time is 2 to 10 minutes.

6. The preparation method according to claim 3 or 4, characterized in that, In step two, the precipitant includes sodium carbonate solution and / or ammonia water, the temperature of the co-precipitation is 50-90°C, the time of the co-precipitation is 0.5-2 hours, and the pH of the co-precipitation is 6-8.

7. The preparation method according to claim 3 or 4, characterized in that, In step three, the organic solvent includes any one or more of ethanol, propanol, n-butanol, and isobutanol; the stirring temperature is 50–90°C; the stirring time is 1–4 hours; the calcination temperature is 200–600°C; the calcination time is 2–8 hours; and the ball milling time is 2–10 minutes.

8. The preparation method according to claim 3 or 4, characterized in that, In step four, the precipitant includes sodium carbonate solution and / or ammonia water, the temperature of the co-precipitation is 40-60°C, the time of the co-precipitation is 0.5-2 hours, the pH of the co-precipitation is 6-8, the stirring time is 1-4 hours, the calcination temperature is 400-600°C, and the calcination time is 2-6 hours.

9. The preparation method according to claim 3 or 4, characterized in that, The preparation method further includes: step five, activation, wherein the activation method includes: the copper-based catalyst obtained in step four is reduced at 150°C to 300°C under a pressure of 0 to 1.0 MPa using a first mixed gas of H2 / N2 with a hydrogen content of 5% to 20% for 4 to 48 hours; the reaction temperature is adjusted to 180 to 270°C and treated with a second mixed gas of H2 / H2O / CH3OH / N2 for 4 to 48 hours, wherein the ratio of H2 / H2O / CH3OH / N2 in the second mixed gas is (40 to 80%):(0 to 5%):(0 to 5%):(20 to 60%).

10. The application of a copper-based catalyst comprising any one of claims 1 to 2 or a copper-based catalyst obtained by any one of claims 3 to 9 in the production of methanol from carbon dioxide.

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