Cu-based catalyst for synthesizing low-carbon alcohol and preparation method of Cu-based catalyst

Abstract

The invention relates to the technical field of catalyst preparation, in particular to a Cu-based catalyst for synthesizing low-carbon alcohol and a preparation method. The preparation method comprises the following steps: S1, pretreatment and preparation of a modified carrier; s2, preparing a precursor, namely dissolving a copper salt and a zinc salt in deionized water, adding polyol, amino acid and an organic phosphine compound, adjusting the pH value to 8.0, reacting for 1-1.5 hours to obtain a precipitate, and washing and drying to obtain the precursor; and S3, catalyst preparation: adding the precursor and the modified carrier into deionized water, adding a high-temperature-resistant polymer, drying, grinding, adding layered sulfide, uniformly mixing, tabletting, molding, roasting in nitrogen, and reducing at 200-220 DEG C to obtain the Cu-based catalyst for synthesizing low-carbon alcohol. According to the Cu-based catalyst for synthesizing the low-carbon alcohol and the preparation method, the problems that in the prior art, a catalyst is poor in stability and needs to be frequently replaced are solved.

Description

Technical Field

[0001] The present application relates to the technical field of catalyst preparation, and in particular to a Cu-based catalyst for synthesizing low-carbon alcohols and a preparation method thereof. Background Art

[0002] Low-carbon alcohols have a high octane number, burn fully and efficiently, and can effectively reduce CO, CO2 and nitrogen oxide emissions. After separation, low-carbon alcohols can be used to obtain single alcohols such as ethanol, propanol, and butanol. These alcohols are important chemical raw materials and can be used to prepare a variety of chemicals. They can also be used as general chemical solvents.

[0003] The main methods for synthesizing low-carbon alcohols include catalytic conversion of synthesis gas, catalytic hydration of low-carbon olefins, and coke oven gas synthesis.

[0004] Current catalysts have the problem of too low selectivity for total alcohols and low-carbon alcohols, making it difficult to efficiently convert raw materials into target low-carbon alcohol products. At the same time, they also produce a large number of by-products, which makes subsequent separation and purification more difficult. In addition, some catalysts are easily deactivated during the reaction. For example, Cu-based catalysts may experience Cu species sintering, which affects their service life and requires frequent catalyst replacement, which is not conducive to industrial continuous production. Summary of the Invention

[0005] The present application provides a Cu-based catalyst for synthesizing low-carbon alcohols and a preparation method thereof, in order to solve the problem in the related art that the catalyst has poor stability and needs to be frequently replaced.

[0006] In a first aspect, a method for preparing a Cu-based catalyst for synthesizing low-carbon alcohols is provided, comprising the following steps: S1: Pretreatment and modified carrier preparation: After mixing attapulgite with deionized water, an inorganic acid solution was added dropwise to adjust the pH to 3.0, ultrasonically treated for 30 minutes, allowed to stand for 0.5-1 hour, filtered and washed until neutral, and dried at 100-110°C for 5-6 hours to obtain a pretreated carrier; The pretreated carrier is mixed with deionized water, rare earth metal salt and transition metal salt are added under stirring, stirred at 50-60° C. for 1.5-2 hours, filtered, dried at 100-110° C. for 11-12 hours, and calcined at 480-500° C. for 2.5-3 hours to obtain a modified carrier; S2: Precursor preparation: Copper salt and zinc salt were dissolved in deionized water at a Cu:Zn molar ratio of 3:1, and polyol was added under stirring. The mixture was reacted at 45-50°C for 30 minutes to obtain a complex solution. Adding an amino acid and an organic phosphine compound to the complex solution, stirring for 10 minutes, then dropping a 1 mol / L sodium carbonate solution to adjust the pH to 8.0, and reacting for 1 to 1.5 hours to obtain a precipitate; The precipitate was washed with deionized water and ethanol in sequence, dried under vacuum at 55-60° C. for 9-10 hours, and ground to pass through a 100-mesh sieve to obtain a precursor; S3: Catalyst preparation: The precursor and the modified carrier are mixed in a mass ratio of 1:2, deionized water is added, and after adding the high temperature resistant polymer, the mixture is stirred and immersed at 35-40°C for 1.5-2h, rotary evaporated to a paste, and then vacuum dried at 70-80°C for 7-8h to obtain a dry material. The mass ratio of the high temperature resistant polymer to the precursor is 1:(15-20); After grinding the dry material, adding the layered sulfide, mixing evenly, pressing into tablets at 20 MPa, crushing through a 50-mesh sieve, placing in a tube furnace, heating to 320-350°C at 2°C / min under nitrogen protection, and calcining for 3 hours to obtain a catalyst precursor, wherein the mass ratio of the layered sulfide to the dry material is 1:50; The catalyst precursor was placed in a H2 / Ar mixed gas with a volume ratio of 1:4, reduced at 200-220°C for 4 hours, naturally cooled to room temperature, and then switched to nitrogen protection to obtain a Cu-based catalyst for synthesizing low-carbon alcohols.

[0007] Preferably, in S1, the mass ratio of attapulgite to deionized water is 1:5, the mass ratio of the pretreated carrier to deionized water is 1:8, and the inorganic acid solution is a 0.1 mol / L nitric acid solution or a hydrochloric acid solution.

[0008] Preferably, in S1, the rare earth metal salt is one of lanthanum nitrate and cerium nitrate, and the mass of the rare earth metal salt is 3-5wt% of the mass of the pretreatment support; the transition metal salt is one of manganese nitrate and zirconium nitrate, and the mass of the transition metal salt is 3-5wt% of the mass of the pretreatment support.

[0009] Preferably, in S2, the amount of deionized water added is 5 times the total mass of the copper salt and the zinc salt, and the molar ratio of the polyol to copper is (0.8-1.2):2; The copper salt is one of copper nitrate and copper acetate, and the zinc salt is one of zinc nitrate and zinc acetate.

[0010] Preferably, in S2, the amino acid is one of sodium aspartate and sodium glutamate, the organic phosphine compound is one of aminoethyl phosphinic acid and diethyl phosphite, and the polyol is one of D-mannitol and sorbitol.

[0011] Preferably, the mass of the amino acid is 6-8% of the total mass of the copper salt and the zinc salt, and the molar ratio of P in the organic phosphine compound to Cu in the copper salt is 0.05:1.

[0012] Preferably, in S3, the high temperature resistant polymer is one of polyimide and polyethersulfone, and the layered sulfide is one of molybdenum disulfide and tungsten disulfide.

[0013] In a second aspect, a Cu-based catalyst for synthesizing lower-carbon alcohols is provided, which is prepared by any of the above methods for preparing a Cu-based catalyst for synthesizing lower-carbon alcohols.

[0014] The beneficial effects of the technical solution provided by this application include: The present application provides a Cu-based catalyst for synthesizing low-carbon alcohols and a preparation method thereof. Copper salts and zinc salts provide Cu 0 / Cu + Active center, Cu 0 Responsible for the activation of H2, Cu + Responsible for the adsorption of CO, polyols and amino acids improve the dispersion of Cu and Zn through complexation, ensuring the uniform distribution of active centers, and the P element introduced by the organic phosphine compound adjusts the electron density of Cu, enhances the non-dissociative adsorption capacity of CO, and promotes the CO insertion reaction, thereby improving the total alcohol selectivity and C 2+ Alcohol percentage; Rare earth metals form stable coordination structures with the hydroxyl groups on the support surface, effectively inhibiting support sintering during the reaction. Transition metals enhance the interaction between the support and the active components through electron transfer, reducing the migration of Cu species. Furthermore, the rigid structure of high-temperature-resistant polymers, acting as binders and dispersants, physically prevents Cu particles from agglomerating. The interlayer confinement effect of layered sulfides (such as molybdenum disulfide) further limits Cu particle growth, enhancing catalyst stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0016] Figure 1 This is a flow chart of the preparation method of the Cu-based catalyst for synthesizing low-carbon alcohols provided in this application. DETAILED DESCRIPTION

[0017] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0018] See also Figure 1 As shown, the present application provides a Cu-based catalyst for synthesizing low-carbon alcohols and a preparation method.

[0019] Example 1 The preparation method of the Cu-based catalyst for synthesizing low-carbon alcohols provided in this embodiment comprises the following steps: S1: Pretreatment and modified carrier preparation: 30 g of attapulgite was mixed with 150 g of deionized water, and a 0.1 mol / L nitric acid solution was added dropwise to adjust the pH to 3.0. The mixture was ultrasonically treated for 30 min, allowed to stand for 1 h, filtered, washed until neutral, and dried at 110 ° C for 6 h to obtain a pretreated support. 20 g of the pretreated support was mixed with 160 g of deionized water, and 0.8 g of lanthanum nitrate and 1 g of manganese nitrate were added under stirring. The mixture was stirred at 60°C for 2 h, filtered, dried at 110°C for 12 h, and calcined at 500°C for 3 h to obtain a modified support. S2: Precursor preparation: After dissolving 18.75 g of copper nitrate [Cu(NO3)2•3H2O] and 4.41 g of zinc nitrate [Zn(NO3)2•6H2O] in 115.8 mL of deionized water, 5.31 g of D-mannitol was added under stirring and reacted at 50°C for 30 min to obtain a complex solution; 1.39 g of sodium aspartate and 0.37 g of aminoethylphosphinic acid were added to the complex solution, stirred for 10 min, and then 1 mol / L sodium carbonate solution was added dropwise to adjust the pH to 8.0. The solution was reacted for 1 h to obtain a precipitate. The precipitate was washed with deionized water and ethanol in sequence, dried under vacuum at 60°C for 10 h, and ground to pass through a 100-mesh sieve to obtain a precursor; S3: Catalyst preparation: 10 g of the precursor was mixed with 20 g of the modified support, and 60 g of deionized water was added. 0.67 g of polyethersulfone was added, and the mixture was stirred and immersed at 40 ° C for 2 h. The mixture was rotary evaporated to a paste, and then vacuum dried at 80 ° C for 8 h to obtain a dry material; The dried material was ground, and 0.61 g of molybdenum disulfide was added. After mixing evenly, the mixture was pressed into tablets at 20 MPa, crushed through a 50-mesh sieve, placed in a tube furnace, and heated to 350°C at 2°C / min under nitrogen protection. The mixture was calcined for 3 h to obtain a catalyst precursor. The catalyst precursor was placed in a H2 / Ar mixed gas with a volume ratio of 1:4, reduced at 220°C for 4 hours, naturally cooled to room temperature, and then switched to nitrogen protection to obtain a Cu-based catalyst for synthesizing low-carbon alcohols.

[0020] Example 2 The preparation method of the Cu-based catalyst for synthesizing low-carbon alcohols provided in this embodiment comprises the following steps: S1: Pretreatment and modified carrier preparation: 30 g of attapulgite was mixed with 150 g of deionized water, and a 0.1 mol / L hydrochloric acid solution was added dropwise to adjust the pH to 3.0. The mixture was ultrasonically treated for 30 min, allowed to stand for 1 h, filtered, washed until neutral, and dried at 100 ° C for 6 h to obtain a pretreated support. 20 g of the pretreated support was mixed with deionized water, and 1 g of cerium nitrate and 0.6 g of zirconium nitrate were added under stirring conditions. The mixture was stirred at 50°C for 2 h, filtered, dried at 100°C for 12 h, and calcined at 480°C for 3 h to obtain a modified support. S2: Precursor preparation: After dissolving 17.25 g of copper acetate [Cu(CH3COO)2•H2O] and 4.32 g of zinc acetate [Zn(CH3COO)2•2H2O] in 107.85 mL of deionized water, 7.84 g of sorbitol was added under stirring and reacted at 45°C for 30 min to obtain a complex solution; 1.72 g of sodium glutamate and 1.04 g of diethyl phosphite were added to the complex solution, stirred for 10 min, and then 1 mol / L sodium carbonate solution was added dropwise to adjust the pH to 8.0. After reacting for 1 h, a precipitate was obtained; The precipitate was washed with deionized water and ethanol in sequence, dried under vacuum at 55°C for 10 h, and ground to pass through a 100-mesh sieve to obtain a precursor; S3: Catalyst preparation: 10 g of the precursor was mixed with 20 g of the modified carrier, and 60 g of deionized water was added. 0.5 g of polyimide was added, and the mixture was stirred and immersed at 35 ° C for 2 h. The mixture was rotary evaporated to a paste, and then vacuum dried at 70 ° C for 8 h to obtain a dry material; The dried material was ground, and 0.61 g of tungsten disulfide was added. After mixing evenly, the mixture was pressed into tablets at 20 MPa, crushed through a 50-mesh sieve, placed in a tube furnace, and heated to 320°C at 2°C / min under nitrogen protection. The mixture was calcined for 3 h to obtain a catalyst precursor. The catalyst precursor was placed in a H2 / Ar mixed gas with a volume ratio of 1:4, reduced at 200°C for 4 hours, naturally cooled to room temperature, and then switched to nitrogen protection to obtain a Cu-based catalyst for synthesizing low-carbon alcohols.

[0021] Example 3 The preparation method of the Cu-based catalyst for synthesizing low-carbon alcohols provided in this embodiment comprises the following steps: S1: Pretreatment and modified carrier preparation: 30 g of attapulgite was mixed with 150 g of deionized water, and a 0.1 mol / L hydrochloric acid solution was added dropwise to adjust the pH to 3.0. The mixture was ultrasonically treated for 30 min, allowed to stand for 1 h, filtered, washed until neutral, and dried at 105 ° C for 6 h to obtain a pretreated support. 20 g of the pretreated support was mixed with deionized water, and 0.8 g of lanthanum nitrate and 0.8 g of zirconium nitrate were added under stirring. The mixture was stirred at 55°C for 2 h, filtered, dried at 105°C for 12 h, and calcined at 490°C for 3 h to obtain a modified support. S2: Precursor preparation: 19.96 g of copper acetate and 7.73 g of zinc nitrate were dissolved in 138.45 mL of deionized water, and 12.34 g of D-mannitol was added under stirring. The mixture was reacted at 48°C for 30 min to obtain a complex solution. 1.94 g of sodium aspartate and 0.96 g of aminoethylphosphinic acid were added to the complex solution, stirred for 10 min, and then 1 mol / L sodium carbonate solution was added dropwise to adjust the pH to 8.0. The solution was reacted for 1 h to obtain a precipitate. The precipitate was washed with deionized water and ethanol in sequence, dried under vacuum at 58°C for 10 h, and ground to pass through a 100-mesh sieve to obtain a precursor; S3: Catalyst preparation: 10 g of the precursor was mixed with 20 g of the modified carrier, and deionized water was added. 0.625 g of polyimide was added, and the mixture was stirred and immersed at 38 ° C for 2 h. The mixture was rotary evaporated to a paste, and then vacuum dried at 75 ° C for 8 h to obtain a dry material; The dried material was ground, and 0.6125 g of molybdenum disulfide was added. After mixing evenly, the mixture was pressed into tablets at 20 MPa, crushed through a 50-mesh sieve, placed in a tube furnace, and heated to 330°C at 2°C / min under nitrogen protection. The mixture was calcined for 3 h to obtain a catalyst precursor. The catalyst precursor was placed in a H2 / Ar mixed gas with a volume ratio of 1:4, reduced at 210°C for 4 hours, naturally cooled to room temperature, and then switched to nitrogen protection to obtain a Cu-based catalyst for synthesizing low-carbon alcohols.

[0022] Example 4 The preparation method of the Cu-based catalyst for synthesizing low-carbon alcohols provided in this embodiment comprises the following steps: S1: Pretreatment and modified carrier preparation: 30 g of attapulgite was mixed with 150 g of deionized water, and a 0.1 mol / L hydrochloric acid solution was added dropwise to adjust the pH to 3.0. The mixture was ultrasonically treated for 30 min, allowed to stand for 0.5 h, filtered, washed until neutral, and dried at 110 ° C for 5 h to obtain a pretreated support. 20 g of the pretreated support was mixed with deionized water, and 0.6 g of cerium nitrate and 0.8 g of manganese nitrate were added under stirring. The mixture was stirred at 60°C for 1.5 h, filtered, dried at 110°C for 11 h, and calcined at 500°C for 2.5 h to obtain a modified support. S2: Precursor preparation: 11.16 g of copper acetate and 3.09 g of zinc acetate were dissolved in 138.45 mL of deionized water, and 10.2 g of D-mannitol was added under stirring. The mixture was reacted at 50°C for 30 min to obtain a complex solution. 0.93 g of sodium glutamate and 0.23 g of diethyl phosphite were added to the complex solution, stirred for 10 min, and then 1 mol / L sodium carbonate solution was added dropwise to adjust the pH to 8.0. After reacting for 1.5 h, a precipitate was obtained; The precipitate was washed with deionized water and ethanol in sequence, dried under vacuum at 60°C for 9 h, and ground to pass through a 100-mesh sieve to obtain a precursor; S3: Catalyst preparation: 10 g of the precursor was mixed with 20 g of the modified carrier, and deionized water was added. 0.625 g of polyimide was added, and the mixture was stirred and immersed at 40 ° C for 1.5 h. The mixture was rotary evaporated to a paste, and then vacuum dried at 80 ° C for 7 h to obtain a dry material; The dried material was ground, and 0.6125 g of molybdenum disulfide was added. After mixing evenly, the mixture was pressed into tablets at 20 MPa, crushed through a 50-mesh sieve, placed in a tube furnace, and heated to 350°C at 2°C / min under nitrogen protection. The mixture was calcined for 3 h to obtain a catalyst precursor. The catalyst precursor was placed in a H2 / Ar mixed gas with a volume ratio of 1:4, reduced at 220°C for 4 hours, naturally cooled to room temperature, and then switched to nitrogen protection to obtain a Cu-based catalyst for synthesizing low-carbon alcohols.

[0023] Comparative Example 1 This comparative example differs from Example 1 in that no rare earth metal salt and no transition metal salt are added to S1, and no organic phosphine is added to S2.

[0024] Comparative Example 2 This comparative example differs from Example 1 in that no rare earth metal salt and no transition metal salt are added to S1, and no layered sulfide is added to S3.

[0025] The Cu-based catalyst for synthesizing lower-carbon alcohols prepared in the above examples (hereinafter referred to as "catalyst") was tested.

[0026] A fixed-bed reactor was used, 1 g of catalyst was loaded in the middle of the reaction tank, synthesis gas was used as raw material (H2 / CO / CO2=60 / 30 / 10, volume ratio), the gas flow rate was 50 mL / min, the reaction pressure was 3 MPa, the reaction temperature was 260°C, and after stable reaction for 8 hours, the product composition was analyzed by gas chromatography, the TCD detector was used to detect permanent gases such as H2 and CO, and the FID detector was used to detect low-carbon alcohols (C1~C5 alcohols) and hydrocarbon by-products.

[0027] The results are shown in Table 1.

[0028] Table 1

[0029] Among them C 2+ Alcohol refers to alcohols containing 2 or more carbon atoms.

[0030] From Table 1, the performance of Example 1 is better. The carrier attapulgite is modified by the synergistic effect of rare earth metal salt lanthanum nitrate and transition metal salt manganese nitrate. 3+ Enhance CO adsorption capacity, Mn 2+ Adjust the distribution of the carrier acid sites to reduce side reactions. The P element of the organic phosphine (aminoethylphosphinic acid) forms an electron transfer effect with Cu, promoting the CO insertion reaction (generating C 2+ The key step of the conversion of CO and C 2+ Alcohol selectivity is the highest.

[0031] In Comparative Example 1, rare earth metal salts and transition metal salts were not used to modify the attapulgite. The carrier could not effectively adjust the acid sites and enhance CO adsorption. In addition, there was no organic phosphine in S2, which could not promote the CO insertion reaction. Therefore, the CO conversion rate and C 2+ The selectivity of alcohols decreased significantly; in Comparative Example 2, rare earth metal salts and transition metal salts were not used to modify the attapulgite, which affected the promoting effect of the support on the reaction, and layered sulfide was not added in step S3, which could not provide more active sites and reduce the activation energy of the reaction, resulting in a decrease in CO conversion rate and C 2+ The alcohol selectivity is lower than that of Example 1 and other examples, but since organic phosphine and the like are retained, the performance is relatively better than that of Comparative Example 1.

[0032] For the catalyst prepared in Example 1, based on the above test, the CO content in the tail gas was detected by gas chromatography (TCD detector) at 100 hours, and the CO conversion rate at 100 hours and the CO conversion rate decay rate at 100 hours were calculated (as shown in the following formula).

[0033]

[0034] The initial CO conversion rate was 43.5%, the CO conversion rate after 100 hours was 39.9%, and the CO conversion rate decay rate after 100 hours was 8.3%. The catalyst prepared in Example 1 has good stability. On the one hand, the support modified with rare earth metal salts and transition metal salts forms La-O-Cu bonds with Cu, limiting the migration and agglomeration of Cu particles. On the other hand, the chelate structure formed by D-mannitol and sodium aspartate maintains high dispersibility. At the same time, the layered structure of molybdenum disulfide (MoS2) physically isolates Cu particles, reducing the chance of contact between particles. This keeps the CO conversion rate decay rate after 100 hours at a low level, meeting the requirements of industrial continuous production.

[0035] The catalyst prepared in Example 1 was subjected to catalytic reactions at different temperatures and pressures. The results are shown in Table 2.

[0036] Table 2

[0037] It can be seen that when the temperature is lowered (240℃, 3MPa), the CO conversion rate decreases and the selectivity is maintained well. This is because low temperature can inhibit side reactions to a certain extent. When the temperature is increased (280℃, 3MPa), the CO conversion rate increases, but Cu will sinter, resulting in C 2+ The selectivity of alcohol decreased. After the pressure was reduced (260℃, 2MPa), the amount of CO adsorption decreased, the conversion rate decreased, the chain growth reaction was affected, and the selectivity decreased. High pressure (260℃, 4MPa) increased the conversion rate of CO, but C 2+ The alcohol selectivity decreased slightly. Therefore, under the reaction conditions of 260°C and 3 MPa, while ensuring a high conversion rate, the side reactions and increased energy consumption caused by high pressure were avoided, maintaining a good balance between activity and selectivity.

[0038] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for preparing a Cu-based catalyst for synthesizing low-carbon alcohols, characterized in that: It includes the following steps: S1: Pretreatment and modified carrier preparation: After mixing attapulgite with deionized water, an inorganic acid solution was added dropwise to adjust the pH to 3.0, ultrasonically treated for 30 minutes, allowed to stand for 0.5-1 hour, filtered and washed until neutral, and dried at 100-110°C for 5-6 hours to obtain a pretreated carrier; The pretreated carrier is mixed with deionized water, rare earth metal salt and transition metal salt are added under stirring, stirred at 50-60° C. for 1.5-2 hours, filtered, dried at 100-110° C. for 11-12 hours, and calcined at 480-500° C. for 2.5-3 hours to obtain a modified carrier; S2: Precursor preparation: Copper salt and zinc salt were dissolved in deionized water at a Cu:Zn molar ratio of 3:1, and polyol was added under stirring. The mixture was reacted at 45-50°C for 30 minutes to obtain a complex solution. Adding an amino acid and an organic phosphine compound to the complex solution, stirring for 10 minutes, then dropping a 1 mol / L sodium carbonate solution to adjust the pH to 8.0, and reacting for 1 to 1.5 hours to obtain a precipitate; The precipitate was washed with deionized water and ethanol in sequence, dried under vacuum at 55-60° C. for 9-10 hours, and ground to pass through a 100-mesh sieve to obtain a precursor; S3: Catalyst preparation: The precursor and the modified carrier are mixed in a mass ratio of 1:2, deionized water is added, and after adding the high temperature resistant polymer, the mixture is stirred and immersed at 35-40°C for 1.5-2h, rotary evaporated to a paste, and then vacuum dried at 70-80°C for 7-8h to obtain a dry material. The mass ratio of the high temperature resistant polymer to the precursor is 1:(15-20); After grinding the dry material, adding the layered sulfide, mixing evenly, pressing into tablets at 20 MPa, crushing through a 50-mesh sieve, placing in a tube furnace, heating to 320-350°C at 2°C / min under nitrogen protection, and calcining for 3 hours to obtain a catalyst precursor, wherein the mass ratio of the layered sulfide to the dry material is 1:50; The catalyst precursor was placed in a H2 / Ar mixed gas with a volume ratio of 1:4, reduced at 200-220°C for 4 hours, naturally cooled to room temperature, and then switched to nitrogen protection to obtain a Cu-based catalyst for synthesizing low-carbon alcohols.

2. The method for preparing a Cu-based catalyst for synthesizing lower alcohols as claimed in claim 1, wherein: In S1, the mass ratio of attapulgite to deionized water is 1:5, the mass ratio of the pretreated carrier to deionized water is 1:8, and the inorganic acid solution is a 0.1 mol / L nitric acid solution or a hydrochloric acid solution.

3. The method for preparing a Cu-based catalyst for synthesizing lower alcohols as claimed in claim 1, wherein: In S1, the rare earth metal salt is one of lanthanum nitrate and cerium nitrate, and the mass of the rare earth metal salt is 3-5wt% of the mass of the pretreatment support; the transition metal salt is one of manganese nitrate and zirconium nitrate, and the mass of the transition metal salt is 3-5wt% of the mass of the pretreatment support.

4. The method for preparing a Cu-based catalyst for synthesizing lower alcohols as claimed in claim 1, wherein: In S2, the amount of deionized water added is 5 times the total mass of the copper salt and the zinc salt, and the molar ratio of the polyol to copper is (0.8-1.2):2; The copper salt is one of copper nitrate and copper acetate, and the zinc salt is one of zinc nitrate and zinc acetate.

5. The method for preparing a Cu-based catalyst for synthesizing lower alcohols as claimed in claim 1, wherein: In S2, the amino acid is one of sodium aspartate and sodium glutamate, the organic phosphine compound is one of aminoethyl phosphinic acid and diethyl phosphite, and the polyol is one of D-mannitol and sorbitol.

6. The method for preparing a Cu-based catalyst for synthesizing lower alcohols according to claim 1 or 5, wherein: The mass of the amino acid is 6-8% of the total mass of the copper salt and the zinc salt. In the organic phosphine compound, the molar ratio of P to Cu in the copper salt is 0.05:

1.

7. The method for preparing a Cu-based catalyst for synthesizing lower alcohols as claimed in claim 1, wherein: In S3, the high temperature resistant polymer is one of polyimide and polyethersulfone, and the layered sulfide is one of molybdenum disulfide and tungsten disulfide.

8. A Cu-based catalyst for synthesizing lower carbon alcohols, characterized in that: The catalyst is prepared by the method for preparing a Cu-based catalyst for synthesizing low-carbon alcohols according to any one of claims 1 to 7.

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