Hydrogenation catalyst and method for producing the same, and method for producing lower alcohol by hydrogenation of carbon dioxide

Abstract

The present application relates to the technical field of catalyst, in particular to a hydrogenation catalyst, a preparation method thereof and a method for preparing low-carbon alcohol by carbon dioxide hydrogenation. The catalyst comprises a carrier and an active component, the carrier comprises a ternary composite carrier containing SiO2, MnO2 and ZrO2, and the active component comprises K element and Cu element. The hydrogenation catalyst of the present application comprises the ternary composite carrier containing SiO2, MnO2 and ZrO2 and the active component containing K element and Cu element, the carrier can well disperse the active component K element and Cu element in the catalyst, effectively limits the growth and aggregation of copper grains at high temperature, prolongs the service life of the catalyst, improves the selectivity and catalytic efficiency of the catalyst.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to hydrogenation catalysts and their preparation methods, and methods for preparing lower alcohols by hydrogenation of carbon dioxide. Background Technology

[0002] With the increasing global energy demand, the over-exploitation and utilization of fossil fuels has brought dual pressures on the environment and energy, making CO2 capture and utilization a growing concern. Low-carbon alcohols, as basic chemical raw materials, serve as a bridge and link between coal chemical, natural gas chemical, and petrochemical industries. They are of great strategic significance for optimizing and adjusting the structure of my country's petrochemical industry, alleviating the contradiction between energy supply and demand, promoting the diversification and quality improvement of raw materials for chemical products, and enhancing international market competitiveness.

[0003] The key to producing lower alcohols from CO2 lies in the catalyst. Catalysts for the hydrogenation of CO2 to produce lower alcohols mainly fall into the following categories: First, modified Cu-Zn-Al methanol synthesis catalysts, primarily modified with alkali metals or alkaline earth metals. While these catalysts promote carbon chain growth to some extent, the hydrogenation product is still predominantly methanol. Second, modified FT synthesis catalysts. These catalysts are inexpensive and have good activity, but their selectivity for hydrocarbons is very high, while the selectivity for lower alcohol mixtures is lower. Third, precious metal catalysts. Although precious metal catalysts have good activity, their high price makes industrial application difficult. For these reasons, most recent patent applications focus on introducing new active components, supports, and improving catalyst preparation methods. CN112246273A discloses a catalyst, preparation method, and application for the conversion of CO2 to produce lower alcohols. This catalyst has a three-layer core-shell structure: a metal core, a nitrogen-doped porous carbon middle layer, and a silica outermost layer. The preparation method is cumbersome and involves expensive template agents, hindering industrial scale-up. Patent CN106311281B discloses a catalyst for the hydrogenation of carbon dioxide to synthesize lower alcohols, its preparation method, and its application. This catalyst is a ternary metal sulfide with a layered structure. A basic nickel carbonate template is prepared by co-precipitation of nickel salt and alkali, followed by the introduction of transition metal molybdenum via ion exchange, impregnation with alkali metal potassium, and finally sulfidation. The reaction results show that this catalyst, when used for the hydrogenation of carbon dioxide, mainly produces methanol and methane. 2+ The alcohol content is not high.

[0004] Therefore, there is an urgent need to develop a new catalyst to solve the problems of low catalytic efficiency and low selectivity in the reduction of carbon dioxide to prepare lower alcohols. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of low selectivity, high price of precious metal catalysts and low catalytic efficiency in the existing technology for the production of lower alcohols from CO2. This invention provides a hydrogenation catalyst and its preparation method, as well as a method for the hydrogenation of carbon dioxide to produce lower alcohols. This catalyst has the characteristics of high selectivity, low cost and high catalytic efficiency.

[0006] To achieve the above objectives, the first aspect of the present invention provides a hydrogenation catalyst comprising a support and an active component, wherein the support comprises a ternary composite support containing SiO2, MnO2, and ZrO2, and the active component comprises K and Cu elements.

[0007] A second aspect of the present invention provides a method for preparing the catalyst described herein, the method comprising:

[0008] 1) Mix Si source and Mn source for the first grinding, then add Zr source for the second grinding;

[0009] 2) Add a pore-forming agent to the second grinding product, calcine to form a ternary composite carrier;

[0010] 3) The ternary composite support is first immersed in Cu solution, first dried and first calcined, then second immersed in K solution, second dried and second calcined to obtain the catalyst.

[0011] The third aspect of the present invention provides a method for preparing lower alcohols by hydrogenation of carbon dioxide, wherein the catalyst is reduced in a reducing atmosphere, and H2 and CO2 react with the reduced catalyst, wherein the catalyst is the catalyst described in any one of claims 1-3.

[0012] Compared with the prior art, the advantages of the present invention are as follows:

[0013] The present invention relates to a hydrogenation catalyst consisting of a ternary composite support containing SiO2, MnO2, and ZrO2 and an active component containing K and Cu elements. In this catalyst, the support can effectively disperse the active components K and Cu elements, effectively limiting the growth and aggregation of copper grains at high temperatures, extending the catalyst life, and improving the catalyst selectivity and catalytic efficiency.

[0014] The inventors of this invention have discovered that by using the method of this invention to prepare the catalyst, the dispersion effect of the support on the active components can be further improved, the catalyst life can be extended, and the selectivity of the catalyst can be improved. Moreover, the entire preparation process does not require additional washing compared with conventional precipitation and impregnation methods, which can save a lot of water and is environmentally friendly. Detailed Implementation

[0015] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0016] The present invention provides a first aspect of a hydrogenation catalyst comprising a support and an active component, wherein the support comprises a ternary composite support containing SiO2, MnO2 and ZrO2, and the active component comprises K and Cu elements.

[0017] The present invention relates to a hydrogenation catalyst consisting of a ternary composite support containing SiO2, MnO2, and ZrO2 and an active component containing K and Cu elements. In this catalyst, the support can effectively disperse the active components K and Cu elements, effectively limiting the growth and aggregation of copper grains at high temperatures, extending the catalyst life, and improving the catalyst selectivity and catalytic efficiency.

[0018] In this invention, as long as the objective of the invention can be achieved, there is no particular limitation on the molar ratio of SiO2 to MnO2 in the ternary composite support. According to a preferred embodiment of the invention, the molar ratio of SiO2 to MnO2 in the ternary composite support is (2-4):1, for example, 2:1, 3:1, or 4:1. By adopting the aforementioned preferred scheme, the catalyst lifetime can be further extended, and the catalyst selectivity and catalytic efficiency can be improved.

[0019] In this invention, as long as the objective of the invention can be achieved, there is no particular limitation on the molar ratio of ZrO2 to MnO2 in the ternary composite support. According to a preferred embodiment of the invention, the molar ratio of ZrO2 to MnO2 in the ternary composite support is (1-4):1, for example, 1:1, 2:1, 3:1, or 4:1. By adopting the aforementioned preferred scheme, the catalyst lifetime can be further extended, and the catalyst selectivity and catalytic efficiency can be improved.

[0020] According to a preferred embodiment of the present invention, the catalyst contains 10-20 wt% copper as oxide and 1-5 wt% potassium as oxide. By adopting the aforementioned preferred embodiment, the catalyst lifetime can be further extended, and the catalyst selectivity and catalytic efficiency can be improved.

[0021] A second aspect of the present invention provides a method for preparing the catalyst described herein, the method comprising:

[0022] 1) Mix Si source and Mn source for the first grinding, then add Zr source for the second grinding;

[0023] 2) Add a pore-forming agent to the second grinding product, calcine to form a ternary composite carrier;

[0024] 3) The ternary composite support is first immersed in Cu solution, first dried and first calcined, then second immersed in K solution, second dried and second calcined to obtain the catalyst.

[0025] The preparation method of this invention prepares the support through stepwise grinding, which eliminates the need for additional washing compared to conventional precipitation methods, saving a significant amount of water and making it environmentally friendly. Furthermore, the introduction of active components through impregnation enhances their dispersion, and the stepwise calcination process strengthens the interaction between the active components and the support. The entire preparation process further improves the dispersion effect of the support on the active components, extends the catalyst lifetime, and enhances the selectivity of the catalyst.

[0026] In this invention, the range of Si sources that can be selected is relatively wide, and commonly used types can all be used in this invention. According to a preferred embodiment of this invention, the Si source is selected from at least one of diatomaceous earth, silica, and silica.

[0027] In this invention, the range of types of Mn source is relatively wide, and commonly used types can be used in this invention. According to a preferred embodiment of this invention, the Mn source is selected from at least one of manganese carbonate, manganese acetate, manganese hydroxide, and manganese sulfate.

[0028] In this invention, the range of Zr sources is relatively wide, and commonly used types can be used in this invention. According to a preferred embodiment of this invention, the Zr source is selected from at least one of zirconium hydroxide, zirconium carbonate, and zirconium nitrate.

[0029] In this invention, the range of types of Cu solution that can be selected is relatively wide, and commonly used types can be used in this invention. According to a preferred embodiment of this invention, the Cu solution is selected from one or two of copper nitrate solution and copper acetate solution, and preferably the copper ion concentration in the Cu solution is 1-8 mol / L.

[0030] In this invention, the range of types of K solution is relatively wide, and commonly used types can be used in this invention. According to a preferred embodiment of this invention, the K solution is selected from at least one of potassium nitrate solution, potassium carbonate solution, and potassium hydroxide solution, and preferably the potassium ion concentration in the K solution is 0.5-8 mol / L.

[0031] In this invention, the range of types of pore-forming agents is relatively wide, and commonly used types can be used in this invention. According to a preferred embodiment of this invention, the pore-forming agent is selected from at least one of graphite, stearic acid, and guar gum powder.

[0032] According to a preferred embodiment of the present invention, the conditions for the first grinding include: grinding for 20-40 minutes until the particle size is 40-80 mesh.

[0033] According to a preferred embodiment of the present invention, the conditions for the second grinding include: grinding for 10-30 minutes until the particle size is 40-80 mesh.

[0034] According to a preferred embodiment of the present invention, the mass of the pore-forming agent added is 1-3 wt% of the amount of the second grinding product.

[0035] In this invention, the range of conditions for calcination and molding is relatively wide. According to a preferred embodiment of this invention, the conditions for calcination and molding include: calcination temperature of 400-550℃.

[0036] According to a preferred embodiment of the present invention, the conditions for the calcination forming include: calcination time of 4-6 hours.

[0037] According to a preferred embodiment of the present invention, the conditions for the first impregnation include: an impregnation temperature of 50-80°C.

[0038] According to a preferred embodiment of the present invention, the conditions for the first impregnation include: an impregnation time of 2-4 hours.

[0039] According to a preferred embodiment of the present invention, the conditions for the first drying include a drying temperature of 80-120°C.

[0040] According to a preferred embodiment of the present invention, the conditions for the first drying include a drying time of 3-5 hours.

[0041] According to a preferred embodiment of the present invention, the conditions for the first calcination include: a calcination temperature of 250-350°C.

[0042] According to a preferred embodiment of the present invention, the conditions for the first roasting include: a roasting time of 2-4 hours.

[0043] According to a preferred embodiment of the present invention, the conditions for the second impregnation include: an impregnation temperature of 50-80°C.

[0044] According to a preferred embodiment of the present invention, the conditions for the second impregnation include: an impregnation time of 1-2 hours.

[0045] According to a preferred embodiment of the present invention, the conditions for the second drying include a drying temperature of 80-120°C.

[0046] According to a preferred embodiment of the present invention, the conditions for the second drying include a drying time of 3-5 hours.

[0047] According to a preferred embodiment of the present invention, the conditions for the second calcination include: a calcination temperature of 150-250°C.

[0048] According to a preferred embodiment of the present invention, the conditions for the second calcination include: a calcination time of 2-4 hours.

[0049] According to a preferred embodiment of the present invention, the first and second impregnation methods are equal-volume impregnation under vacuum conditions, and before impregnation, the ternary composite carrier is sized into tablets of a certain size, such as Φ5×5mm.

[0050] The third aspect of the present invention provides a method for preparing lower alcohols by hydrogenation of carbon dioxide, wherein the catalyst is reduced in a reducing atmosphere, and H2 and CO2 react with the reduced catalyst, wherein the catalyst is the catalyst described in any one of claims 1-3.

[0051] The method for preparing lower alcohols by carbon dioxide hydrogenation provided by this invention has a high carbon dioxide conversion rate and high selectivity for lower alcohols. The reaction is green and environmentally friendly, which is conducive to industrial application and promotion, and has important social and economic significance.

[0052] According to a preferred embodiment of the present invention, the catalyst is crushed to a particle size of 16-40 mesh before use.

[0053] According to a preferred embodiment of the present invention, the conditions for the contact reaction include: a reaction temperature of 250-350°C, a pressure of 6.0-8.0 MPa, and a space velocity of 6000-10000 h⁻¹. -1 Under these conditions, the molar ratio of H2 to CO2 is 2-4:1.

[0054] This invention utilizes a temperature of 250℃, a pressure of 6.0 MPa, and a space velocity of 6000 h⁻¹. -1 The molar ratio of H2:CO2 = 2:1 is used to illustrate the advantages of the present invention.

[0055] According to a preferred embodiment of the present invention, the reducing atmosphere is a hydrogen atmosphere.

[0056] According to a preferred embodiment of the present invention, the reduction conditions include: a reduction temperature of 150-200°C and a reduction time of 8-24 hours.

[0057] The advantages of this invention are illustrated by using a reduction temperature of 200°C and a reduction time of 12 hours.

[0058] According to a preferred embodiment of the present invention, the lower alcohol is selected from at least one of methanol, ethanol, propanol and isobutanol.

[0059] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Unless otherwise specified, the conditions in the embodiments are conventional conditions or conditions recommended by the manufacturer. Unless otherwise stated, all raw materials involved in the embodiments are commercially available products.

[0060] Example 1

[0061] According to the molar ratio of Si:Mn:Zr = 2:1:1, 257g of diatomaceous earth, 230g of manganese carbonate, and 327g of zirconium hydroxide were weighed. Diatomaceous earth and manganese carbonate were added separately to a grinding mill, and the mixture was ground for 30 minutes until the particle size reached 60 mesh. After grinding, zirconium hydroxide was added, and the mixture was ground for another 20 minutes until the particle size reached 60 mesh. After grinding, 10g of stearic acid was added, and the mixture was calcined in a muffle furnace at 450℃ for 4 hours in air atmosphere. Then, the mixture was sheeted into Φ5×5mm tablets to obtain a layered ternary composite carrier with a SiO2 to MnO2 molar ratio of 2:1 and a ZrO2 to MnO2 molar ratio of 1:1. 200g of support was weighed, and copper nitrate was weighed according to a CuO content of 20% by mass, and a 100ml solution was prepared with a copper ion concentration of 5mol / L. The ternary support was impregnated at 80℃ for 3h under vacuum, dried at 120℃ for 4h, and then calcined at 300℃ for 3h. Potassium nitrate was weighed according to a K2O content of 2% by mass, and a 100ml solution was prepared with a potassium ion concentration of 0.9mol / L. The same process was carried out under vacuum at 80℃ for 2h, dried at 120℃ for 4h, and calcined at 200℃ for 3h, to obtain catalyst C1 with a copper oxide content of 16.2wt% and a potassium oxide content of 1.6wt%.

[0062] Example 2

[0063] According to the molar ratio of Si:Mn:Zr = 2:1:2, 172g of silica, 191g of manganese acetate, and 466g of zirconium carbonate were weighed. First, silica and manganese acetate were added separately to a grinding mill, and the mixture was ground for 40 minutes until the particle size was 40 mesh. After grinding, zirconium carbonate was added, and the mixture was ground for another 30 minutes until the particle size was 40 mesh. After grinding, the mixture was placed in a muffle furnace and calcined at 550℃ for 4 hours in an air atmosphere. Then, 10g of guar gum powder was added, and the mixture was shaped into Φ5×5mm tablets to obtain a layered ternary composite carrier with a SiO2 to MnO2 molar ratio of 2:1 and a ZrO2 to MnO2 molar ratio of 2:1. 200g of support was weighed, and copper acetate was weighed according to a CuO mass percentage of 10%, and a 100ml solution was prepared with a copper ion concentration of 2.5mol / L. The ternary support was impregnated with the solution at 50℃ for 4 hours under vacuum, dried at 120℃, and then calcined at 350℃ for 2 hours. Potassium hydroxide was weighed according to a K2O mass percentage of 3%, and a 100ml solution was prepared with a potassium ion concentration of 1.35mol / L. The solution was then impregnated with the solution at 50℃ for 2 hours under vacuum, dried at 120℃, and calcined at 250℃ for 2 hours. Catalyst C2 with a copper oxide mass content of 8.8wt% and a potassium oxide mass content of 2.6wt% was obtained.

[0064] Example 3

[0065] According to the molar ratio of Si:Mn:Zr = 3:1:1, 231g of silica, 114g of manganese hydroxide, and 435g of zirconium nitrate were weighed. First, silica and manganese hydroxide were added separately to a grinding mill and ground for 20 minutes until the particle size was 40 mesh. After that, zirconium nitrate was added and grinding was continued for 10 minutes until the particle size was 50 mesh. After grinding, the mixture was placed in a muffle furnace and calcined at 400℃ in air atmosphere for 6 hours. Then, 10g of graphite was added, and the mixture was sheeted into Φ5×5mm tablets to obtain a layered ternary composite carrier with a SiO2 to MnO2 molar ratio of 3:1 and a ZrO2 to MnO2 molar ratio of 1:1. 200g of support was weighed, and copper nitrate was weighed according to a CuO content of 15% by mass to prepare a 100ml solution with a copper ion concentration of 3.75mol / L. The ternary support was impregnated at 70℃ for 2 hours under vacuum, dried at 120℃, and then calcined at 250℃ for 4 hours. Potassium carbonate was weighed according to a K2O content of 5% by mass to prepare a 100ml solution with a potassium ion concentration of 2.25mol / L. The same solution was then impregnated at 70℃ for 1 hour under vacuum, dried at 120℃, and calcined at 250℃ for 3 hours to obtain catalyst C3 with a copper oxide content of 12.5wt% and a potassium oxide content of 4.0wt%.

[0066] Example 4

[0067] Following the method of Example 1, except that the molar ratio of SiO2 to MnO2 in the ternary composite support is 2.5:1 and the molar ratio of ZrO2 to MnO2 is 1:1, while other parameters remain unchanged, catalyst C4 is prepared.

[0068] Example 5

[0069] Following the method of Example 1, except that the molar ratio of ZrO2 to MnO2 in the ternary composite support is 3.5:1 and the molar ratio of ZrO2 to MnO2 is 1:1, while other parameters remain unchanged, catalyst C5 is prepared.

[0070] Example 6

[0071] Catalyst C6 was prepared by following the method of Example 1, except that the mass content of copper was 12% and the mass content of potassium was 2.5%, while other parameters remained unchanged.

[0072] Example 7

[0073] According to the ratio Si:Mn:Zr = 4:1:1, 267g of diatomaceous earth, 168g of manganese sulfate, and 177g of zirconium hydroxide were weighed. First, diatomaceous earth and manganese sulfate were added separately to a grinding mill and ground for 30 minutes until the particle size reached 40 mesh. After grinding, zirconium hydroxide was added and grinding continued for 15 minutes until the particle size reached 80 mesh. After grinding, the mixture was placed in a muffle furnace and calcined at 500℃ for 5 hours in an air atmosphere. Then, 10g of guar gum powder was added, and the mixture was shaped into Φ5×5mm tablets to obtain a layered ternary composite carrier with a SiO2 to MnO2 molar ratio of 4:1 and a ZrO2 to MnO2 molar ratio of 1:1. 200g of support was weighed, and copper nitrate was weighed according to a CuO content of 20% by mass to prepare a 100ml solution with a copper ion concentration of 5mol / L. The ternary support was impregnated at 60℃ for 4 hours under vacuum, dried at 120℃, and then calcined at 300℃ for 4 hours. Potassium nitrate was weighed according to a K2O content of 4% by mass to prepare a 100ml solution with a potassium ion concentration of 1.8mol / L. The same solution was then impregnated at 60℃ for 1 hour under vacuum, dried at 120℃, and calcined at 200℃ for 2 hours to obtain catalyst C7 with a copper oxide content of 16.0wt% and a potassium oxide content of 3.2wt%.

[0074] Example 8

[0075] According to the ratio Si:Mn:Zr = 2:1:4, 86g of diatomaceous earth, 99g of manganese carbonate, and 455g of zirconium hydroxide were weighed out. First, diatomaceous earth and manganese carbonate were added separately to a grinding mill and ground for 40 minutes until the particle size was 45 mesh. After that, zirconium hydroxide was added and grinding continued for 30 minutes until the particle size was 80 mesh. After grinding, the mixture was placed in a muffle furnace and calcined at 500℃ for 5 hours in an air atmosphere. Then, 10g of graphite was added, and the mixture was sheeted into Φ5×5mm tablets to obtain a layered ternary composite carrier with a SiO2 to MnO2 molar ratio of 2:1 and a ZrO2 to MnO2 molar ratio of 4:1. 200g of support was weighed, and copper acetate was weighed according to a CuO mass percentage of 10%, and a 100ml solution was prepared with a copper ion concentration of 2.5mol / L. The ternary support was impregnated with an equal volume at 50℃ for 4h under vacuum, dried at 120℃, and then calcined at 350℃ for 2h. Potassium hydroxide was weighed according to a K2O mass percentage of 3%, and a 100ml solution was prepared with a potassium ion concentration of 1.35mol / L. The same solution was then impregnated with an equal volume at 50℃ for 2h under vacuum, dried at 120℃, and calcined at 250℃ for 2h. Catalyst C8 with a copper oxide mass content of 8.8wt% and a potassium oxide mass content of 2.6wt% was obtained.

[0076] Example 9

[0077] According to the ratio Si:Mn:Zr = 4:1:4, 147g of silica, 106g of manganese acetate, and 828g of zirconium nitrate were weighed. First, silica and manganese acetate were added separately to a grinding mill and ground for 40 minutes until the particle size reached 55 mesh. After grinding, zirconium nitrate was added and grinding continued for 30 minutes until the particle size reached 60 mesh. After grinding, the mixture was placed in a muffle furnace and calcined at 550℃ in air atmosphere for 4 hours. Then, 10g of stearic acid was added, and the mixture was tableted into Φ5×5mm tablets, yielding a layered ternary composite carrier with a SiO2 to MnO2 molar ratio of 4:1 and a ZrO2 to MnO2 molar ratio of 4:1. 200g of support was weighed, and copper acetate was weighed according to a CuO mass percentage of 20%, and a 100ml solution was prepared with a copper ion concentration of 5mol / L. The ternary support was impregnated with an equal volume at 50℃ for 4h under vacuum, dried at 120℃, and then calcined at 350℃ for 2h. Potassium hydroxide was weighed according to a K2O mass percentage of 5%, and a 100ml solution was prepared with a potassium ion concentration of 2.25mol / L. The same solution was then impregnated with an equal volume at 50℃ for 2h under vacuum, dried at 120℃, and calcined at 250℃ for 2h to obtain catalyst C9 with a copper oxide mass content of 16wt% and a potassium oxide mass content of 4wt%.

[0078] Example 10

[0079] According to the ratio Si:Mn:Zr = 3:1:2, 175g of diatomaceous earth, 87g of manganese hydroxide, and 310g of zirconium hydroxide were weighed. First, diatomaceous earth and manganese hydroxide were added separately to a grinding mill and ground for 20 minutes until the particle size reached 65 mesh. After grinding, zirconium hydroxide was added and grinding continued for another 30 minutes until the particle size reached 65 mesh. After grinding, the mixture was placed in a muffle furnace and calcined at 400℃ in air atmosphere for 6 hours. Then, 10g of stearic acid was added, and the mixture was tableted into Φ5×5mm tablets to obtain a layered ternary composite carrier with a SiO2 to MnO2 molar ratio of 3:1 and a ZrO2 to MnO2 molar ratio of 2:1. 200g of support was weighed, and copper nitrate was weighed according to the mass percentage of CuO 18%, and a 100ml solution was prepared with a copper ion concentration of 4.5mol / L. The ternary support was impregnated with an equal volume at 60℃ for 4h under vacuum, dried at 120℃, and then calcined at 350℃ for 2h. Potassium hydroxide was weighed according to the mass percentage of K2O 5%, and a potassium ion concentration of 2.25mol / L was prepared with a 100ml solution. The same process was carried out under vacuum at 60℃ for 2h, dried at 120℃, and calcined at 250℃ for 2h to obtain catalyst C10 with a copper oxide mass content of 14.5wt% and a potassium oxide mass content of 4wt%.

[0080] Example 11

[0081] Similar to Example 1, but with a different preparation method, diatomaceous earth, zirconium hydroxide, and manganese carbonate were milled once in a mill, while other aspects remained unchanged, to obtain catalyst C11.

[0082] Comparative Example 1

[0083] According to the ratio Si:Zr = 2:1, 257g of diatomaceous earth and 327g of zirconium hydroxide were weighed out. Diatomaceous earth and zirconium hydroxide were added to the grinding mill and ground for 30 minutes until the particle size was 20 mesh. After grinding, the mixture was placed in a muffle furnace and calcined at 450℃ for 4 hours in an air atmosphere. Then, 10g of stearic acid was added and the mixture was shaped into Φ5×5mm tablets to obtain layered SiO2 and ZrO2 with a molar ratio of 2:1. 200g of support was weighed, and copper nitrate was weighed according to the mass percentage of CuO 20%, and a 100ml solution was prepared. The ternary support was impregnated with an equal volume at 80℃ for 3h under vacuum, dried at 120℃, and then calcined at 300℃ for 3h. Potassium nitrate was weighed according to the mass percentage of K2O 2%, and a 100ml solution was prepared. The ternary support was impregnated with an equal volume at 80℃ for 2h under vacuum, dried at 120℃, and calcined at 200℃ for 3h to obtain catalyst D1 with a copper oxide mass content of 16.2wt% and a potassium oxide mass content of 1.6wt%.

[0084] Comparative Example 2

[0085] 47g copper nitrate, 33g zinc nitrate, 37g aluminum nitrate, 80g zirconium nitrate, and 23g cobalt nitrate were dissolved in 2000ml deionized water to obtain a mixed nitrate solution. A 1mol / L sodium carbonate aqueous solution was prepared. The mixed nitrate solution and sodium carbonate solution were added concurrently to 300ml of deionized water at 80℃. The reaction temperature was controlled at 80℃, and the neutralization endpoint was controlled at pH=7. Then, the temperature was raised to 90℃ for aging for 1h. The solution was filtered and washed, dried at 120℃ for 4h, calcined in air at 500℃ for 2h, and 2g graphite was added. The solution was then sized into Φ5×5mm tablets to obtain catalyst D2.

[0086] Comparative Example 3

[0087] The method of Example 1 was followed, except that manganese was replaced with titanium or aluminum. Catalyst D3 was obtained.

[0088] Comparative Example 4

[0089] Catalyst D4 was prepared according to the method of Example 1, except that the active component consisted only of K.

[0090] Comparative Example 5

[0091] Catalyst D5 was prepared according to the method of Example 1, except that the active component was only Cu.

[0092] Preparation example:

[0093] Catalysts C1-11 and D1-4 were applied to the production of lower alcohols from carbon dioxide in a micro-fixed-bed continuous flow reactor. Tablet catalysts were crushed, with a loading of 2 mL and a particle size of 16-40 mesh. Reduction was carried out at 200℃ for 12 h under a H2 atmosphere, followed by reaction at 250℃, a pressure of 6.0 MPa, and a space velocity of 6000 h⁻¹. -1 H2:CO2 (molar ratio) = 2. After the reaction stabilized for 2 hours, the liquid in the liquid collector was emptied and the timing was started. The collector was cooled with circulating water. After 2.5 hours, the liquid in the collector was collected, weighed, and subjected to chromatographic quantitative analysis. The result was the initial activity.

[0094] Table 1 Activity evaluation results

[0095]

[0096]

[0097] As can be seen from Table 1, the catalyst of this invention exhibits excellent activity and C content when used in the reaction of carbon dioxide to produce lower alcohols. 2+ The selectivity indicates that the catalyst of this invention can be well applied to the reaction of carbon dioxide to produce lower alcohols.

[0098] Activity test:

[0099] The C1 catalyst was loaded into a fixed-bed reactor using the same method as in the preparation example. The reduction temperature, reaction temperature, pressure, space velocity, and H2:CO2 (molar ratio) were changed, and a heat resistance test and a 500-hour life test were conducted. After the catalyst was heat-treated for 5 hours in a reaction atmosphere, at atmospheric pressure and 400°C, it was restored to the above-mentioned activity evaluation conditions. The measured activity results are the activity after heat resistance. The results are shown in Tables 2 and 3.

[0100] Table 2 Effect of reaction conditions on catalytic performance

[0101]

[0102] Table 3 Catalyst activity after heat resistance and 500h

[0103]

[0104] The data in Tables 2 and 3 show that the reduction temperature is 180-230℃, the reaction temperature is 200-300℃, the reaction pressure is 6.0-8.0 MPa, and the space velocity is 6000-10000 h⁻¹. -1 Under these reaction conditions, with an H2:CO2 (molar ratio) of 2-4, the catalyst performed excellently, and both the heat resistance test and the 500-hour life test showed that the catalyst's CO2 conversion rate and total alcohol selectivity did not decrease significantly.

[0105] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a hydrogenation catalyst for the hydrogenation of carbon dioxide to produce lower alcohols, characterized in that, The method includes: 1) Mix Si source and Mn source for the first grinding, then add Zr source for the second grinding; 2) Add a pore-forming agent to the second grinding product, calcine to form a ternary composite carrier; 3) The ternary composite support is first immersed in Cu solution, first dried and first calcined, then second immersed in K solution, second dried and second calcined to obtain the catalyst.

2. The preparation method according to claim 1, wherein, The Si source is selected from at least one of diatomaceous earth, silica, and silica; and / or The Mn source is selected from at least one of manganese carbonate, manganese acetate, manganese hydroxide, and manganese sulfate; and / or The Zr source is selected from at least one of zirconium hydroxide, zirconium carbonate, and zirconium nitrate; and / or The Cu solution is selected from one or both of copper nitrate solution and copper acetate solution; and / or The K solution is selected from at least one of potassium nitrate solution, potassium carbonate solution, and potassium hydroxide solution.

3. The preparation method according to claim 2, wherein, The copper ion concentration in the Cu solution is 1-8 mol / L; and / or The potassium ion concentration in the K solution is 0.5-8 mol / L.

4. The preparation method according to claim 1 or 2, wherein, The pore-forming agent is selected from at least one of graphite, stearic acid, and guar gum.

5. The preparation method according to claim 1 or 2, wherein, In step 1), The first grinding conditions include: grinding for 20-40 minutes, grinding to a particle size of 40-80 mesh; and / or The conditions for the second grinding include: grinding for 10-30 minutes until the particle size is 40-80 mesh.

6. The preparation method according to claim 1 or 2, wherein, In step 2), The mass of the pore-forming agent added is 1-3 wt% of the amount of the second grinding product; and / or The conditions for calcination and forming include: calcination temperature of 400-550℃; And / or, roasting time 4-6 hours.

7. The preparation method according to claim 1 or 2, wherein, In step 3), The conditions for the first impregnation include: an impregnation temperature of 50-80°C; and / or an impregnation time of 2-4 hours; and / or The conditions for the first drying stage include: a drying temperature of 80-120℃; and / or a drying time of 3-5 hours; and / or The conditions for the first roasting include: a roasting temperature of 250-350℃; and / or a roasting time of 2-4 hours; and / or The conditions for the second impregnation include: an impregnation temperature of 50-80℃; and / or an impregnation time of 1-2 hours; and / or The second drying conditions include: a drying temperature of 80-120℃; and / or a drying time of 3-5 hours; and / or The conditions for the second roasting include: a roasting temperature of 150-250℃; and / or a roasting time of 2-4 hours.

8. A method for preparing lower alcohols by hydrogenation of carbon dioxide, characterized in that, The catalyst is reduced in a reducing atmosphere, and H2 and CO2 react with the reduced catalyst. The catalyst is prepared by the method described in any one of claims 1-7.

9. The method according to claim 8, wherein, The conditions for the contact reaction include: a reaction temperature of 250-350℃, a pressure of 6.0-8.0 MPa, and a space velocity of 6000-10000 h⁻¹. -1 Under these conditions, the molar ratio of H2 to CO2 is 2-4:1; and / or The reducing atmosphere is a hydrogen atmosphere.

10. The method according to claim 9, wherein, The reduction conditions include: a reduction temperature of 150-200℃ and a reduction time of 8-24 hours; and / or The lower alcohol is selected from at least one of methanol, ethanol, propanol, and isobutanol.

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