A series catalyst for hydrogenating carbon dioxide to produce mixed alcohols, as well as its preparation method and application

Abstract

The invention discloses a series catalyst for preparing mixed alcohols by hydrogenating carbon dioxide, and its preparation method and application. The series catalyst consists of an alkali metal-modified copper-based bimetallic compound and a zirconium-based solid solution. The alkali metal-modified copper-based bimetallic compound is expressed as M1-Cu-M2 / SiO2 (M1 is one of Na and K, and M2 is one of Co and Fe), wherein SiO2 is a carrier, M1, Cu, and M2 are active metals of the catalyst, the molar ratio of Cu to M2 is 20:1-1:20, and the loading amount of M1 is 1wt%-10wt%; the zirconium-based solid solution is expressed as M3-Zr (M3 is one of Zn, Ce, and In), and the molar ratio of M3 to Zr is 1:10-1:2. The series catalyst simultaneously has the ability to reverse water gas reaction and carbon chain growth and generate alcohol, thereby directly converting CO2 hydrogenation into alcohol. C in the product 2+ The mass fraction of alcohol in the total alcohol is above 80%.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a series catalyst for preparing mixed alcohols by hydrogenating carbon dioxide, a preparation method thereof, and an application thereof. Background Art

[0002] Since the 19th century, humanity has been exploiting fossil energy on a large scale, releasing greenhouse gases such as CO2 into the environment. Excessive CO2 emissions have led to a series of environmental problems, including the greenhouse effect and ocean acidification. Converting CO2 into high-value-added chemicals, such as alkanes, alkenes, alcohols, and aromatics, can effectively alleviate the environmental problems caused by excessive CO2 emissions while reducing over-reliance on fossil energy. This is of great significance to the sustainable development of the energy and chemical industries. Alcohols can be used as fuels and fuel additives, as well as as raw materials or intermediates in the production of many chemical products. This wide range of applications has led to a continuous increase in market demand for alcohols, and the conversion of CO2 into alcohol products has attracted widespread attention. The development of catalysts is crucial for the CO2 hydrogenation reaction to produce alcohols.

[0003] The catalysts for CO2 hydrogenation to produce mixed alcohols are divided into four systems according to the different active components: 1. Precious metal catalysts represented by Rh group, which have good C 2+ 1. The first is the modified Mo-based catalyst, which has good sulfur resistance, but has low overall activity and harsh reaction conditions. 2. The second is the modified methanol synthesis catalyst, which has high catalytic activity, but the main product is methanol. 4. The third is the modified Fischer-Tropsch catalyst, which has the characteristics of low cost, high activity and mild reaction conditions, but the products are complex and the selectivity for hydrocarbons is high.

[0004] Tandem catalysis, which promotes reactions through coupling between different active components, has been applied in numerous reaction systems. The ratio and combination of active components in tandem catalysts influence product distribution. Therefore, efficiently coupling the various components of a tandem catalyst to promote carbon chain growth and enhance selectivity for lower alcohols is crucial in the CO2 hydrogenation to lower alcohols process. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a series catalyst for preparing mixed alcohols by hydrogenation of carbon dioxide and a preparation method thereof, so as to solve the problems of the existing catalyst system for preparing mixed alcohols by hydrogenation of CO2, such as high manufacturing cost, low overall activity, harsh reaction conditions, and C 2+ Technical problems include poor alcohol selectivity, complex products, and high hydrocarbon selectivity.

[0006] The technical solution adopted in the present invention is:

[0007] A tandem catalyst for hydrogenating carbon dioxide to prepare mixed alcohols comprises a copper-based bimetallic catalyst and a zirconium-based solid solution catalyst; the copper-based bimetallic catalyst is expressed as M1-Cu-M2 / SiO2, wherein SiO2 serves as a carrier, M1, Cu, and M2 serve as active metals of the catalyst, M1 is one of the alkali metals Na and K, and M2 is one of the transition metals Co and Fe; the zirconium-based solid solution catalyst is expressed as M3-Zr, wherein M3 is one of the Zn, Ce, and In.

[0008] Preferably, in the copper-based bimetallic catalyst, the loading amount of M1 is 1-10 wt%, and the molar ratio of Cu and M2 is (0.05-20):1; in the zirconium-based solid solution catalyst, the molar ratio of M3 to Zr is (0.5-10):1.

[0009] The preparation method of the above-mentioned tandem catalyst comprises the following steps:

[0010] (3.1) Preparation of copper-based bimetallic catalysts:

[0011] (3.1.1) A soluble metal salt of Cu and a soluble metal salt of M2 are dissolved in deionized water, followed by the addition of SiO2 sol to obtain a mixed solution. Aqueous ammonia is added dropwise to the mixed solution until the pH reaches 10-11, and the solution is stirred and aged. The aged mixed solution is then heated to evaporate ammonia to lower the pH of the solution to neutral, thereby obtaining a concentrated solution. The concentrated solution is filtered, washed, and dried to obtain a solid sample A. The obtained solid sample A is calcined in air to obtain Cu-M2 / SiO2.

[0012] (3.1.2) A soluble metal salt of M1 is dissolved in deionized water and impregnated onto Cu-M2 / SiO2. After drying, the mixture is calcined in air to obtain the M1-Cu-M2 / SiO2 catalyst.

[0013] (3.2) Preparation of zirconium-based solid solution catalysts:

[0014] A soluble metal salt of Zr and a soluble metal salt of M3 are dissolved in deionized water, a precipitant is added, and the mixture is stirred and aged. The aged solution is filtered, washed, and dried to obtain a solid sample B. The obtained solid sample B is then calcined in air to obtain an M3-Zr catalyst.

[0015] (3.3) Preparation of tandem catalysts:

[0016] The M1-Cu-M2 / SiO2 catalyst prepared in step (3.1) is combined with the M3-Zr catalyst prepared in step (3.2) to obtain a tandem catalyst.

[0017] Preferably, the soluble metal salt of Cu, the soluble metal salt of M1, the soluble metal salt of M2, the soluble metal salt of Zr, and the soluble metal salt of M3 are at least one of the chloride, nitrate, sulfate, and acetate of the metal, respectively.

[0018] Preferably, the precipitant is at least one of water-soluble carbonates, water-soluble bicarbonates, and water-soluble hydroxides.

[0019] Preferably, in step (3.3), the M1-Cu-M2 / SiO2 catalyst and the M3-Zr catalyst are combined in a mass ratio of (0.5-2):1.

[0020] Preferably, in step (3.3), the catalyst combination is a mixture of M1-Cu-M2 / SiO2 catalyst and M3-Zr catalyst, or a double-bed combination.

[0021] The M1-Cu-M2 / SiO2 catalyst and the M3-Zr catalyst are particle catalysts or powder catalysts.

[0022] A second object of the present invention is to provide a method for using the above-mentioned tandem catalyst in the hydrogenation of carbon dioxide to produce mixed alcohols.

[0023] Preferably, the application method comprises loading the series catalyst in a fixed bed reactor, introducing raw gas H2 and CO2 for hydrogenation to produce mixed alcohols, wherein the molar ratio of H2 to CO2 is 2 to 4; the reaction temperature is 250 to 350°C; the reaction pressure is 3 to 5 MPa; and the reaction space velocity is 1000 to 10000 mL / (gcat·h).

[0024] Preferably, the series catalyst is tableted and granulated before loading to obtain a 40-60 mesh catalyst.

[0025] Beneficial effects of the present invention:

[0026] (1) The Cu-based catalyst in the tandem catalyst can maintain a highly dispersed and stable coexistence of M2C after reduction x -Cu 0 Active sites can directly convert CO2 into alcohols by hydrogenation; Zr-based solid solution catalysts can provide more C1 intermediates, improve the activity of the catalyst, and promote the stable progress of the reaction.

[0027] (2) The CO2 conversion rate reaches 30%, and the total alcohol selectivity reaches about 20%, of which C 2+ The mass fraction of alcohol in the total alcohol reaches more than 80%.

[0028] (3) The catalyst composition of the present invention is low-cost and is conducive to large-scale production and application. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with a preferred embodiment.

[0030] Example 1

[0031] (1) Preparation of catalyst

[0032] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 15.42 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0033] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-1Cu1Co / SiO2.

[0034] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0035] (1.4) Take 1g of the above-prepared 2wt% K-1Cu1Co / SiO2 catalyst and 1Zn5Zr powder, mix them evenly, and then press and granulate them to obtain a 40-60 mesh granular catalyst, which is recorded as 2wt% K-1Cu1Co / SiO2+1Zn5Zr / (1:1).

[0036] (2) Catalyst performance evaluation

[0037] The 2wt% K-1Cu1Co / SiO2+1Zn5Zr / (1:1) catalyst was loaded into the constant temperature zone in the middle of the reaction tube, and the upper and lower empty spaces of the reaction tube were filled with 40-60 mesh quartz sand. The catalyst was reduced with H2 before the reaction. The reduction conditions were: temperature 320°C, flow rate 150mL·min -1 After the reduction is completed, the gas flow is switched to a mixture of H2 and CO2 with a molar ratio of 3, the system pressure is slowly increased to 5 MPa, and the temperature is lowered to 300 ° C to start the reaction.

[0038] Example 2

[0039] (1) Preparation of catalyst

[0040] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 15.42 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0041] (1.2) Using the equal volume impregnation method, 0.041 g of Na2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% Na-1Cu1Co / SiO2.

[0042] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0043] (1.4) Take 1g of the above-prepared 2wt% Na-1Cu1Co / SiO2 catalyst and 1Zn5Zr powder, mix them evenly, and then press and granulate them to obtain a 40-60 mesh granular catalyst, which is recorded as 2wt% Na-1Cu1Co / SiO2+1Zn5Zr / (1:1).

[0044] (2) Catalyst performance evaluation

[0045] A 2 wt% Na-1Cu1Co / SiO2+1Zn5Zr (1:1) catalyst was loaded into the constant temperature zone in the middle of the reaction tube, and the upper and lower free spaces of the reaction tube were filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1.

[0046] Example 3

[0047] (1) Preparation of catalyst

[0048] (1.1) 2.42 g of Cu(NO3)2·3H2O and 4.04 g of Fe(NO3)2·9H2O were dissolved in 100 mL of deionized water. 15.95 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Fe / SiO2.

[0049] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Fe / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-1Cu1Fe / SiO2.

[0050] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0051] (1.4) Take 1g of the above-prepared 2wt% K-1Cu1Fe / SiO2 catalyst and 1Zn5Zr catalyst powder, mix them evenly, and then press and granulate them to obtain a 40-60 mesh granular catalyst, which is recorded as 2wt% K-1Cu1Fe / SiO2+1Zn5Zr / (1:1).

[0052] (2) Catalyst performance evaluation

[0053] A 2 wt% K-1 Cu1 Fe / SiO2 + 1 Zn5 Zr / (1:1) catalyst was placed in the constant temperature zone in the middle of the reaction tube, and the upper and lower empty spaces of the reaction tube were filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1.

[0054] Example 4

[0055] (1) Preparation of catalyst

[0056] (1.1) 4.84 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 23.39 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the mixture was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 2Cu1Co / SiO2.

[0057] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 2Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-2Cu1Co / SiO2.

[0058] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0059] (1.4) Take 1g of the above-prepared 2wt% K-2Cu1Co / SiO2 catalyst and 1Zn5Zr catalyst powder, mix them evenly, and then press and granulate them to obtain a 40-60 mesh granular catalyst, which is recorded as 2wt% K-2Cu1Co / SiO2+1Zn5Zr / (1:1).

[0060] (2) Catalyst performance evaluation

[0061] A 2 wt% K-2Cu1Co / SiO2+1Zn5Zr / (1:1) catalyst was placed in the constant temperature zone in the middle of the reaction tube, and the upper and lower empty spaces of the reaction tube were filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1.

[0062] Example 5

[0063] (1) Preparation of catalyst

[0064] (1.1) 2.42 g of Cu(NO3)2·3H2O and 5.82 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 22.94 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the mixture was dried in a 100°C oven for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu2Co / SiO2.

[0065] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu2Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h to obtain 2 wt% K-1Cu2Co / SiO2.

[0066] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0067] (1.4) Take 1g of the above-prepared 2wt% K-1Cu2Co / SiO2 catalyst and 1Zn5Zr catalyst powder, mix them evenly, and then press and granulate them to obtain a 40-60 mesh granular catalyst, which is recorded as 2wt% K-1Cu2Co / SiO2+1Zn5Zr / (1:1).

[0068] (2) Catalyst performance evaluation

[0069] A 2 wt% K-1 Cu2Co / SiO2+1 Zn5Zr / (1:1) catalyst was placed in the constant temperature zone in the middle of the reaction tube, and the upper and lower empty spaces of the reaction tube were filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1.

[0070] Example 6

[0071] (1) Preparation of catalyst

[0072] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 22.94 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0073] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-1Cu1Co / SiO2.

[0074] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0075] (1.4) 1 g of each of the 2 wt% -1 Cu1Co / SiO2 catalyst and 1 Zn5Zr catalyst prepared above was tableted and granulated to obtain 40-60 mesh granular catalysts.

[0076] (2) Catalyst performance evaluation

[0077] A 2wt% K-1Cu1Co / SiO2 catalyst and a 1Zn5Zr catalyst were separately loaded into the constant temperature zone of a reaction tube, with the 2wt% K-1Cu1Co / SiO2 catalyst on top and the 1Zn5Zr catalyst on the bottom, separated by approximately 1 cm of quartz sand. The remaining portion of the reaction tube was filled with 40-60 mesh quartz sand. Reduction and reaction conditions were the same as in Example 1.

[0078] Example 7

[0079] (1) Preparation of catalyst

[0080] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 22.94 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0081] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-1Cu1Co / SiO2.

[0082] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0083] (1.4) 1 g of the 2 wt% K-1Cu1Co / SiO2 catalyst and 1 Zn5Zr catalyst prepared above were respectively tableted and granulated to obtain 40-60 mesh granular catalysts.

[0084] (2) Catalyst performance evaluation

[0085] A 2 wt% K-1Cu1Co / SiO2 catalyst and a 1Zn5Zr catalyst were separately loaded into the constant temperature zone of a reaction tube, with the 1Zn5Zr catalyst on top and the 2 wt% K-1Cu1Co / SiO2 catalyst on the bottom, separated by approximately 1 cm of quartz sand. The remaining portion of the reaction tube was filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1.

[0086] Example 8

[0087] (1) Preparation of catalyst

[0088] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 22.94 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0089] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-1Cu1Co / SiO2.

[0090] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0091] (1.4) Take 1g of the 2wt% K-1Cu1Co / SiO2 catalyst and 1Zn5Zr catalyst prepared above, and press and granulate them to obtain particles of 40-60 mesh. Mix the two catalyst particles evenly to obtain a mixed catalyst, which is recorded as 2wt% K-1Cu1Co / SiO2 particles + 1Zn5Zr particles / (1:1).

[0092] (2) Catalyst performance evaluation

[0093] A 2 wt% K-1 Cu1 Co / SiO2 particle + 1 Zn5 Zr particle (1:1) catalyst was placed in the constant temperature zone in the middle of the reaction tube, and the remaining space above and below the reaction tube was filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1.

[0094] Example 9

[0095] (1) Preparation of catalyst

[0096] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 15.42 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0097] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-1Cu1Co / SiO2.

[0098] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0099] (1.4) Take 2g of the 2wt% K-1Cu1Co / SiO2 catalyst prepared above and 1g of 1Zn5Zr powder, mix them evenly, and then press and granulate them to obtain a 40-60 mesh granular catalyst, which is recorded as 2wt% K-1Cu1Co / SiO2+1Zn5Zr / (2:1).

[0100] (2) Catalyst performance evaluation

[0101] A 2 wt% K-1 Cu1 Co / SiO2 + 1 Zn5 Zr (2:1) catalyst was loaded into the constant temperature zone in the middle of the reaction tube, and the upper and lower empty spaces of the reaction tube were filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1.

[0102] Example 10

[0103] (1) Preparation of catalyst

[0104] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 15.42 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0105] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-1Cu1Co / SiO2.

[0106] (1.3) Take 2.98g Zn(NO3)2·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Zn5Zr.

[0107] (1.4) Take 1g of the above-prepared 2wt% K-1Cu1Co / SiO2 catalyst and 2g of 1Zn5Zr powder, mix them evenly, and then press and granulate them to obtain a 40-60 mesh granular catalyst, recorded as 2wt% K-1Cu1Co / SiO2+1Zn5Zr / (1:2).

[0108] (2) Catalyst performance evaluation

[0109] A 2 wt% K-1Cu1Co / SiO2+1Zn5Zr / (1:2) catalyst was loaded into the constant temperature zone in the middle of the reaction tube, and the upper and lower empty spaces of the reaction tube were filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1.

[0110] Example 11

[0111] (1) Preparation of catalyst

[0112] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 15.42 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0113] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-1Cu1Co / SiO2.

[0114] (1.3) Take 3.01g In(NO3)3·xH2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1In5Zr.

[0115] (1.4) Take 1g of the above-prepared 2wt% K-1Cu1Co / SiO2 catalyst and 1In5Zr powder, mix them evenly, and then press and granulate them to obtain a 40-60 mesh granular catalyst, which is recorded as 2wt% K-1Cu1Co / SiO2+1In5Zr / (1:1).

[0116] (2) Catalyst performance evaluation

[0117] A 2 wt% K-1Cu1Co / SiO2+1In5Zr (1:1) catalyst was loaded into the constant temperature zone in the middle of the reaction tube, and the upper and lower empty spaces of the reaction tube were filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1.

[0118] Example 12

[0119] (1) Preparation of catalyst

[0120] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 15.42 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0121] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min for 5 h to obtain 2 wt% K-1Cu1Co / SiO2.

[0122] (1.3) Take 4.34g Ce(NO3)3·6H2O and 21.47g Zr(NO3)4·5H2O and dissolve them in 150mL deionized water. Add (NH4)2CO3 at a concentration of 1mol / L in an 80℃ water bath until the pH is about 9. Stir and age for 5h. After filtering and washing, dry in a 100℃ oven for 12h. Then, heat it to 500℃ in a muffle furnace at a heating rate of 5℃ / min and calcine it for 5h to obtain a catalyst denoted as 1Ce5Zr.

[0123] (1.4) Take 1g of the above-prepared 2wt% K-1Cu1Co / SiO2 catalyst and 1Ce5Zr powder, mix them evenly, and then press and granulate them to obtain a 40-60 mesh granular catalyst, which is recorded as 2wt% K-1Cu1Co / SiO2+1Ce5Zr / (1:1).

[0124] (2) Catalyst performance evaluation

[0125] 2 wt% K-1Cu1Co / SiO2+1Ce5Zr / (1:1) catalyst was loaded into the constant temperature zone in the middle of the reaction tube, and the upper and lower empty spaces of the reaction tube were filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as in Example 1. Comparative Example 1

[0126] (1) Preparation of catalyst

[0127] (1.1) 2.42 g of Cu(NO3)2·3H2O and 2.91 g of Co(NO3)2·6H2O were dissolved in 100 mL of deionized water. 22.94 g of 40 wt% SiO2 sol was then added. NH3·H2O was added dropwise to the mixed solution until the pH reached 11. The mixture was stirred and aged for 5 h. The solution was then heated to 80°C to evaporate ammonia until the pH dropped to approximately 7. After filtration and washing, the solution was dried in an oven at 100°C for 12 h. The mixture was then heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h. The resulting catalyst was designated 1Cu1Co / SiO2.

[0128] (1.2) Using the equal volume impregnation method, 0.053 g of K2CO3 was weighed and dissolved in an appropriate amount of deionized water. The mixture was impregnated onto 1.5 g of 1Cu1Co / SiO2. After drying, the mixture was heated to 500°C in a muffle furnace at a heating rate of 5°C / min and calcined for 5 h to obtain 2 wt% K-1Cu1Co / SiO2.

[0129] (1.32) Take 1g of the 2wt% K-1Cu1Co / SiO2 catalyst prepared above and compress and granulate it to obtain a 40-60 mesh granular catalyst.

[0130] (2) Catalyst performance evaluation

[0131] 2 wt% K-1Cu1Co / SiO2 catalyst was loaded into the constant temperature zone in the middle of the reaction tube, and the upper and lower empty spaces of the reaction tube were filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as those in Example 1.

[0132] Comparative Example 2

[0133] (1) Preparation of catalyst

[0134] (1.1) Dissolve 2.98 g of Zn(NO₃)₂·6H₂O and 21.47 g of Zr(NO₃)₄·5H₂O in 150 mL of deionized water. Add 1 mol / L (NH₄)₂CO₃ in an 80°C water bath until the pH reaches approximately 9. Stir and age for 5 h. Filter, wash, and dry in an oven at 100°C for 12 h. Then, heat the mixture to 500°C in a muffle furnace at a heating rate of 5°C / min and calcine for 5 h to obtain a catalyst designated 1Zn5Zr.

[0135] (1.2) Take 1g of the 1Zn5Zr catalyst prepared above and compress and granulate it to obtain a 40-60 mesh granular catalyst.

[0136] (2) Catalyst performance evaluation

[0137] The 1Zn5Zr catalyst was loaded into the constant temperature zone in the middle of the reaction tube, and the free space above and below the reaction tube was filled with 40-60 mesh quartz sand. The reduction and reaction conditions were the same as those in Example 1.

[0138] Table 1 Catalyst performance test results

[0139]

[0140]

[0141] As can be seen from Table 1, compared with the single copper-based bimetallic catalyst or zirconium-based solid solution catalyst (Comparative Examples 1-2), the tandem catalysts prepared by the present invention (Examples 1-12) can effectively improve the CO2 conversion rate and C 2+ In addition, when powder mixing was used and the mass ratio of copper-based catalyst to zirconium-based solid solution catalyst was 1:1, the CO2 conversion rate was 37.5%, C 2+ The selectivity of alcohol is 20.1%, C 2+ The technical effect is that the proportion of alcohol in the total alcohol is as high as 92.5%.

[0142] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also within the scope of protection of the present invention.

Claims

1. A tandem catalyst for hydrogenating carbon dioxide to prepare mixed alcohols, characterized in that: The invention is composed of a copper-based bimetallic catalyst and a zirconium-based solid solution catalyst; the copper-based bimetallic catalyst is expressed as M1-Cu-M2 / SiO2, wherein SiO2 is a carrier, M1, Cu, and M2 are active metals of the catalyst, M1 is one of alkali metals Na and K, and M2 is one of transition metals Co and Fe; the zirconium-based solid solution catalyst is expressed as M3-Zr, wherein M3 is one of Zn, Ce, and In; The preparation method of the M1-Cu-M2 / SiO2 catalyst is as follows: dissolving a soluble metal salt of M1 in deionized water and impregnating the mixture onto Cu-M2 / SiO2, followed by drying and calcining the mixture in air.

2. The tandem catalyst according to claim 1, characterized in that In the copper-based bimetallic catalyst, the loading amount of M1 is 1-10wt%, and the molar ratio of Cu and M2 is (0.05-20):1; in the zirconium-based solid solution catalyst, the molar ratio of M3 to Zr is (0.5-10):

1.

3. The method for preparing the tandem catalyst according to claim 1 or 2, characterized in that: The following steps are involved: Step (3.1) Preparation of copper-based bimetallic catalyst: In step (3.1.1), a soluble metal salt of Cu and a soluble metal salt of M2 are dissolved in deionized water, and then SiO2 sol is added to obtain a mixed solution; aqueous ammonia is added dropwise to the mixed solution until the pH reaches 10 to 11, and the solution is stirred and aged; the aged mixed solution is then heated to evaporate ammonia to lower the pH of the solution to neutral, thereby obtaining a concentrated solution; the concentrated solution is filtered, washed, and dried to obtain a solid sample A; The obtained solid sample A was calcined in air to obtain Cu-M2 / SiO2; Step (3.1.2): dissolving a soluble metal salt of M1 in deionized water and impregnating the mixture onto Cu-M2 / SiO2, drying the mixture, and calcining the mixture in air to obtain an M1-Cu-M2 / SiO2 catalyst; Step (3.2) Preparation of zirconium-based solid solution catalyst: A soluble metal salt of Zr and a soluble metal salt of M3 are dissolved in deionized water, a precipitant is added, and the mixture is stirred and aged. The aged solution is filtered, washed, and dried to obtain a solid sample B. The obtained solid sample B is then calcined in air to obtain an M3-Zr catalyst. Step (3.3) Preparation of tandem catalyst: The M1-Cu-M2 / SiO2 catalyst prepared in step (3.1) is combined with the M3-Zr catalyst prepared in step (3.2) to obtain a tandem catalyst.

4. The preparation method according to claim 3, wherein: The soluble metal salt of Cu, the soluble metal salt of M1, the soluble metal salt of M2, the soluble metal salt of Zr, and the soluble metal salt of M3 are at least one of chlorides, nitrates, sulfates, and acetates of the metals.

5. The preparation method according to claim 3, wherein: The precipitant is at least one of water-soluble carbonates, water-soluble bicarbonates, and water-soluble hydroxides.

6. The preparation method according to claim 3, wherein: In step (3.3), the M1-Cu-M2 / SiO2 catalyst and the M3-Zr catalyst are combined in a mass ratio of (0.5-2):

1.

7. The preparation method according to claim 3, wherein: In step (3.3), the catalyst combination is a mixture of M1-Cu-M2 / SiO2 catalyst and M3-Zr catalyst, or a double-bed combination.

8. Use of the tandem catalyst according to claim 1 in preparing mixed alcohols by hydrogenation of carbon dioxide.

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