Doped Cu-based catalyst, preparation method and application thereof in ethanol synthesis

Abstract

The present invention relates to the technical field of alcohol synthesis catalysts, specifically a doped Cu-based catalyst, a preparation method, and its application in ethanol synthesis. The preparation method comprises the following steps: S1, pretreating mesoporous silica; S2, loading zinc ions onto the pretreated mesoporous silica; S3, converting the zinc ions loaded on the loaded mesoporous silica into zinc oxide; S4, treating the mesoporous silica adsorbed with zinc oxide with EDTA; S5, subjecting the zinc oxide on the mesoporous silica to point-specific adsorption of copper ions; S6, removing the mesoporous silica through alkaline treatment, and heating and reducing the catalyst to obtain a doped Cu-based catalyst. The doped Cu-based catalyst prepared by the present invention has uniform distribution of copper ions and zinc oxide, effectively improving the material's catalytic efficiency for synthesis gas.

Description

Technical Field

[0001] The present invention relates to the technical field of alcohol synthesis catalysts, in particular to a doped Cu-based catalyst, a preparation method and application thereof in ethanol synthesis. Background Art

[0002] Ethanol is an extremely important chemical raw material, widely used in organic synthesis, dyes, fuels, pharmaceuticals, coatings, and the defense industry. Over one hundred chemical products are produced from ethanol. In recent years, with the continuous increase in ethanol's deep-processed products and the continued expansion of its chemical applications, ethanol's position in the national economy has become increasingly important and prominent.

[0003] Cu / ZnO catalysts have achieved significant technological breakthroughs in the conversion of syngas (H₂ + CO) to ethanol. These catalysts can produce ethanol without the addition of alkali metals or Fischer-Tropsch elements, defying conventional wisdom about Cu / ZnO as a methanol catalyst. However, ethanol yields are low. ZnO is an n-type semiconductor, and its stoichiometric ratio can deviate due to intrinsic defects such as oxygen vacancies and zinc interstitials. Therefore, doping can modify the electronic structure, crystal structure, and surface properties of Cu / ZnO catalysts, thereby improving their catalytic activity, selectivity, and stability. However, numerous challenges remain regarding the selection of Cu / ZnO doping materials, controlling the doping ratio, and optimizing doping methods. While some existing doped catalysts have achieved improved performance to some extent, they suffer from drawbacks such as poor doping uniformity, unstable bonding with the substrate, complex preparation processes, and high costs, limiting their large-scale industrial application.

[0004] To this end, in response to the problems raised in the above background technology, those skilled in the art have proposed a doped Cu-based catalyst, a preparation method and its application in synthesizing ethanol. Summary of the Invention

[0005] The object of the present invention is to provide a doped Cu-based catalyst, a preparation method and application thereof in ethanol synthesis, so as to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for preparing a doped Cu-based catalyst comprises the following steps:

[0008] S1. Dispersing mesoporous silica into a toluene solution containing 3-aminopropyltrimethoxysilane, heating to 50-90° C., reflux reaction for 5-10 hours, then filtering, washing with sufficient toluene, and drying at low temperature to obtain pretreated mesoporous silica;

[0009] S2, soaking the pretreated mesoporous silica obtained in step S1 in a 0.5-1 mol / L zinc nitrate solution for 3-8 hours, and then filtering to obtain mesoporous silica loaded with zinc ions;

[0010] S3, soaking the mesoporous silica loaded with zinc ions obtained in step S2 in ammonia water with a pH of 8-10 for 1-4 hours, then filtering, placing the filtered product in a muffle furnace and calcining it at 600-800° C. for 2-5 hours to obtain mesoporous silica loaded with zinc oxide;

[0011] S4, placing the zinc oxide-loaded mesoporous silica obtained in step S3 into a 0.1-0.5% by mass EDTA aqueous solution, heating it to 40-60° C. for reaction for 3-6 hours, and then filtering to obtain a filtrate;

[0012] S5. The filtrate obtained in step S4 is placed in a mixture of copper nitrate solution and a structural additive and soaked for 1-2 hours, then sodium carbonate is added to adjust the pH to 8-9, and filtered to obtain a crude product;

[0013] S6. The crude product obtained in step S5 is placed in a sodium hydroxide solution with a concentration of 4-6 mol / L, heated to 60-80° C. and reacted for 1-3 hours, and then filtered. The filtered product is washed with sufficient deionized water and dried at 60-100° C. The dried product is placed in a muffle furnace and reduced in a hydrogen and nitrogen atmosphere at 200-300° C. for 2-4 hours to obtain a doped Cu-based catalyst after reduction.

[0014] Furthermore, in step S1, the mass ratio of silicon dioxide, 3-aminopropyltrimethoxysilane and toluene is 1:(0.1-0.5):(50-60).

[0015] Furthermore, in step S2, the mass ratio between the pretreated mesoporous silica and the zinc nitrate solution is 1:(30-50).

[0016] Furthermore, in step S3, the mass ratio between the mesoporous silica loaded with zinc ions and the ammonia solution is 1:(10-20).

[0017] Furthermore, in step S4, the mass ratio between the mesoporous silica loaded with zinc oxide and the EDTA aqueous solution is 1:(70-100).

[0018] Furthermore, the concentration of copper nitrate in step S5 is 0.1-0.4 mol / L, the mass ratio of the filtrate to the mixed solution of copper nitrate and the structural additive is 1:(20-30), the structural additive is a combination of any two metal salts of Al, Ga or Cr, specifically aluminum nitrate, gallium nitrate or chromium nitrate, and the concentration of the structural additive is 0.005 mol / L.

[0019] Furthermore, in step S6, the mass ratio of the crude product to the sodium hydroxide solution is 1:(50-100), and the volume ratio of the hydrogen to the nitrogen is 1:4.

[0020] A doped Cu-based catalyst is prepared by the above-mentioned method for preparing a doped Cu-based catalyst.

[0021] Application of the above-mentioned doped Cu-based catalyst in ethanol synthesis.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention can effectively improve the catalytic efficiency of the catalyst by introducing structural additives (doped with aluminum, gallium, and chromium ions). The preparation method of the catalyst is simple and the catalytic stability is strong.

[0024] 2. The present invention uses mesoporous silica as a carrier, first modifies the mesoporous silica with a silane coupling agent, allows a large amount of zinc ions to be uniformly bound in the pores of the mesoporous silica, then synthesizes zinc oxide in the pores of the mesoporous silica by adjusting the pH, and finally synthesizes the Cu / ZnO catalyst;

[0025] 3. In the present invention, zinc oxide is combined with copper ions, and a high-temperature calcination step is introduced in step S3. The high-temperature calcination eliminates the amino groups introduced in step S1 and the hydroxyl groups carried by the mesoporous silica itself, thereby weakening the binding ability between the copper ions and silica. At the same time, the complexation effect of EDTA strengthens the binding between the copper ions and zinc oxide. Finally, the mesoporous silica carrier is removed by a strong alkaline solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a process flow chart for preparing a doped Cu-based catalyst in the present invention;

[0027] Figure 2 The XRD pattern of the doped Cu-based catalyst prepared in the present invention;

[0028] Figure 3 TEM images, HRTEM images, and Cu particle size images of the doped Cu-based catalysts prepared in Examples 1-4 of the present invention (a1-d1 are TEM images, a2-d2 are HRTEM images, and a3-d3 are Cu particle size histograms). DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] See also Figure 1-3 , the present invention provides:

[0031] Example 1

[0032] A method for preparing a doped Cu-based catalyst comprises the following steps:

[0033] S1. Dispersing 2.24 g of mesoporous silica into a toluene solution containing 3-aminopropyltrimethoxysilane (0.448 g) and toluene (123.2 g). Heating to 65° C. and reflux for 9 h, followed by filtering, washing with sufficient toluene, and drying at low temperature to obtain pretreated mesoporous silica.

[0034] S2, soaking 2.12 g of the pretreated mesoporous silica obtained in step S1 in 84.2 g of a 0.8 mol / L zinc nitrate solution for 5.5 h, and then filtering to obtain mesoporous silica loaded with zinc ions;

[0035] S3, soaking 2.12 g of mesoporous silica loaded with zinc ions obtained in step S2 in 31.6 g of ammonia water with a pH of 8.5 for 3 h, and then filtering the filtered product. The product was placed in a muffle furnace and calcined at 700 ° C for 4 h to obtain mesoporous silica loaded with zinc oxide;

[0036] S4, placing 2.08 g of the mesoporous silica loaded with zinc oxide obtained in step S3 into 176.5 g of a 0.4% by mass EDTA aqueous solution, heating to 55° C. for reaction for 4 h, and then filtering to obtain a filtrate;

[0037] S5. 1.96 g of the filtrate obtained in step S4 was placed in 54.8 g of a 0.2 mol / L copper nitrate solution and soaked for 1.4 h. Then, sodium carbonate was added to adjust the pH to 8.5, and the crude product was filtered;

[0038] S6. 1.85 g of the crude product obtained in step S5 was placed in 108 g of a 5 mol / L sodium hydroxide solution, heated to 75° C. for reaction for 2 h, and then filtered. The filtered product was washed with sufficient deionized water and dried at 80° C. The dried product was placed in a muffle furnace and reduced at 260° C. in a hydrogen and nitrogen atmosphere for 3 h, with a volume ratio of hydrogen to nitrogen of 1:4. After reduction, a doped Cu-based catalyst (abbreviated as CZ) was obtained.

[0039] Example 2

[0040] A method for preparing a doped Cu-based catalyst comprises the following steps:

[0041] S1. Dispersing 2.54 g of mesoporous silica into a toluene solution containing 3-aminopropyltrimethoxysilane (0.254 g of 3-aminopropyltrimethoxysilane and 127 g of toluene), heating to 50° C., reflux for 5 h, filtering, washing with sufficient toluene, and drying at low temperature to obtain pretreated mesoporous silica;

[0042] S2, soaking 2.44 g of the pretreated mesoporous silica obtained in step S1 in 73.2 g of a 0.5 mol / L zinc nitrate solution for 3 h, and then filtering to obtain mesoporous silica loaded with zinc ions;

[0043] S3, soaking 2.25 g of the mesoporous silica loaded with zinc ions obtained in step S2 in 22.5 g of ammonia water at a pH of 8 for 1 hour, and then filtering the filtered product. The product was placed in a muffle furnace and calcined at 600 ° C for 2 hours to obtain mesoporous silica loaded with zinc oxide;

[0044] S4, placing 2.24 g of the mesoporous silica loaded with zinc oxide obtained in step S3 into 156.8 g of a 0.1% by mass EDTA aqueous solution, heating to 40° C. for reaction for 3 h, and then filtering to obtain a filtrate;

[0045] S5, 2.11 g of the filtrate obtained in step S4 was placed in 42.2 g of a mixed solution of 0.1 mol / L copper nitrate, 0.005 mol / L aluminum nitrate, and 0.005 mol / L chromium nitrate and soaked for 1 h, then sodium carbonate was added to adjust the pH to 8, and the crude product was filtered;

[0046] S6. 2.01 g of the crude product obtained in step S5 was placed in 100.5 g of a 4 mol / L sodium hydroxide solution, heated to 60° C. for reaction for 1 h, and then filtered. The filtered product was washed with sufficient deionized water and dried at 60° C. The dried product was placed in a muffle furnace and reduced at 200° C. in a hydrogen and nitrogen atmosphere for 2 h, with a volume ratio of hydrogen to nitrogen of 1:4. After reduction, a doped Cu-based catalyst (abbreviated as CZAC, where A represents Al and C represents Cr) was obtained.

[0047] Example 3

[0048] A method for preparing a doped Cu-based catalyst comprises the following steps:

[0049] S1. Disperse 1.96 g of mesoporous silica into a toluene solution containing 3-aminopropyltrimethoxysilane, where the amount of 3-aminopropyltrimethoxysilane is 0.98 g and the amount of toluene is 117.6 g. Heat to 90° C., reflux for 10 h, filter, wash with sufficient toluene, and dry at low temperature to obtain pretreated mesoporous silica.

[0050] S2, soaking 1.84 g of the pretreated mesoporous silica obtained in step S1 in 92 g of a 1 mol / L zinc nitrate solution for 8 h, and then filtering to obtain mesoporous silica loaded with zinc ions;

[0051] S3, soaking 1.77 g of the mesoporous silica loaded with zinc ions obtained in step S2 in 35.4 g of ammonia water with a pH of 10 for 4 hours, and then filtering the filtered product. The product was placed in a muffle furnace and calcined at 800° C. for 5 hours to obtain mesoporous silica loaded with zinc oxide;

[0052] S4, placing 1.69 g of the mesoporous silica loaded with zinc oxide obtained in step S3 into 169 g of a 0.5% by mass EDTA aqueous solution, heating to 60° C. for reaction for 6 h, and then filtering to obtain a filtrate;

[0053] S5, 1.65 g of the filtrate obtained in step S4 was placed in 49.5 g of a mixed solution of 0.4 mol / L copper nitrate, 0.005 mol / L gallium nitrate, and 0.005 mol / L chromium nitrate and soaked for 2 h, then sodium carbonate was added to adjust the pH to 9, and the crude product was filtered;

[0054] S6. 1.61 g of the crude product obtained in step S5 was placed in 161 g of a 6 mol / L sodium hydroxide solution, heated to 80° C., and reacted for 3 h. The reaction was then filtered, and the filtered product was washed with sufficient deionized water and dried at 100° C. The dried product was placed in a muffle furnace and reduced at 300° C. in a hydrogen and nitrogen atmosphere for 4 h. The volume ratio of hydrogen to nitrogen was 1:4. After reduction, a doped Cu-based catalyst (abbreviated as CZCG, where C represents Cr and G represents Ga) was obtained.

[0055] Example 4

[0056] A method for preparing a doped Cu-based catalyst comprises the following steps:

[0057] S1. Dispersing 2.06 g of mesoporous silica into a toluene solution containing 3-aminopropyltrimethoxysilane (0.62 g of 3-aminopropyltrimethoxysilane and 116.2 g of toluene), heating to 75° C., reflux for 8.5 h, filtering, washing with sufficient toluene, and drying at low temperature to obtain pretreated mesoporous silica;

[0058] S2, soaking 1.88 g of the pretreated mesoporous silica obtained in step S1 in 65.8 g of a 0.8 mol / L zinc nitrate solution for 6.5 h, and then filtering to obtain mesoporous silica loaded with zinc ions;

[0059] S3, soaking 1.82 g of the mesoporous silica loaded with zinc ions obtained in step S2 in 22.4 g of ammonia water at a pH of 9 for 2 h, and then filtering the filtered product. The product was placed in a muffle furnace and calcined at 750 ° C for 4 h to obtain mesoporous silica loaded with zinc oxide;

[0060] S4, placing 1.71 g of the mesoporous silica loaded with zinc oxide obtained in step S3 into 164 g of a 0.3% by mass EDTA aqueous solution, heating to 55° C. for reaction for 4 h, and then filtering to obtain a filtrate;

[0061] S5, 1.55 g of the filtrate obtained in step S4 was placed in a mixed solution of 38.7 g of 0.2 mol / L copper nitrate, 0.005 mol / L gallium nitrate, and 0.005 mol / L aluminum nitrate and soaked for 1.6 h, then sodium carbonate was added to adjust the pH to 8, and the crude product was filtered;

[0062] S6. The 1.44 g crude product obtained in step S5 was placed into 97.6 g of 5.5 mol / L sodium hydroxide solution, heated to 75° C., and reacted for 2.5 hours. The mixture was then filtered. The filtered product was washed with sufficient deionized water and dried at 85° C. The dried product was placed in a muffle furnace and reduced at 280° C. in a hydrogen and nitrogen atmosphere for 3 hours, with a volume ratio of hydrogen to nitrogen of 1:4. After reduction, a doped Cu-based catalyst (abbreviated as CZAG, where A represents Al and G represents Ga) was obtained.

[0063] Comparative Example 1

[0064] The difference between Comparative Example 1 and Example 1 is that the step of calcining the filtered product in a muffle furnace in step S3 is omitted, and the remaining steps are exactly the same as those in Example 1.

[0065] Comparative Example 2

[0066] The difference between Comparative Example 2 and Example 1 is that the step of soaking the mesoporous silica loaded with zinc oxide in the EDTA aqueous solution in step S4 is omitted, and the remaining steps are exactly the same as those in Example 1.

[0067] Comparative Example 3

[0068] Compared with Comparative Example 2, Comparative Example 3 also eliminates the step of calcining the filtered product in the muffle furnace in step S3, and the remaining steps are exactly the same as those in Comparative Example 2.

[0069] Comparative Example 4

[0070] Comparative Example 4 uses a coprecipitation method to prepare the catalyst. The specific operation method is to add sodium carbonate to the copper nitrate and zinc nitrate solution, adjust the pH to 8.5, filter out the precipitate, and then calcine it. After calcination, the temperature is lowered for reduction. In this comparative example, the concentrations of copper nitrate and zinc nitrate, as well as the calcination conditions and reduction conditions are exactly the same as those in Example 1.

[0071] Performance Testing

[0072] 1 mL of catalyst pellets was loaded into an 8 mm inner diameter quartz reaction tube. Prior to activity evaluation, the catalyst was reduced in situ in 20% H2 / N2 at 300°C for 2 hours at a gas flow rate of 100 mL / min and atmospheric pressure. After reduction, feed gases (CO + H2) were introduced into the reactor, maintaining the reaction pressure at 4 MPa. The syngas inlet flow rate was 100 mL / min, with a gas flow ratio of n(H2):n(CO) = 2:1. During the reaction, product composition was analyzed using a Hisense GC-950 chromatograph. Organic components (C1-C5 hydrocarbons, dimethyl ether, methanol, and ethanol) were analyzed online using a flame ionization detector (FID, HP-PLOT / Q column), while inorganic components (H2, CO, CH4, and CO2) were analyzed online using a thermal conductivity detector (TCD, TDX-01 column). An FID detector (HP-INNOWAX column) was used to detect alcohols in the liquid product offline. The CO conversion rate formula is as follows:

[0073] ,

[0074] Where i represents all C-containing compounds in the gas and liquid products except CO, n(CO) out Indicates the amount of CO in the outlet gas (mol), n i (g) and n i (I) represents the number of carbon atoms (mol) of component i in the outlet gas and liquid phase respectively:

[0075] Space-time yield of ethanol (STY, g·g -1 ·h -1 ) = (ethanol mass / catalyst mass) / reaction time

[0076] Table 1: CO conversion and space-time yield of catalysts prepared in Examples 1-4 and Comparative Examples 1-4

[0077]

[0078] A comparative analysis of the data from Example 1 and Examples 2-4 in Table 1 demonstrates that the present invention significantly improves catalyst performance by introducing a structural additive (aluminum nitrate, gallium nitrate, or chromium nitrate), specifically demonstrating significant increases in both ethanol space-time yield and CO conversion. Further comparison of the data from Example 1 with Comparative Examples 1-3 reveals that high-temperature calcination and EDTA treatment effectively optimize catalyst performance, resulting in simultaneous improvements in both ethanol space-time yield and CO conversion. Furthermore, a comparison of Example 1 with Comparative Example 4 demonstrates that the preparation method employed in the present invention exhibits significant advantages in catalytic performance compared to the traditional coprecipitation method.

[0079] Characterization Test

[0080] In order to analyze the crystal structure of the catalysts, we analyzed their XRD spectra. Figure 2 As shown in the figure, it can be seen that the series of catalysts have similar structural characteristics, which indicates that the introduction of structural additives has little effect on the crystal structure of the catalyst. Obvious diffraction peaks were observed at 43.4°, 50.5° and 74.1°, corresponding to Cu 0 The (111), (200) and (220) crystal planes of the catalyst are not observed. It is worth noting that the ZnO signal peak does not appear in the XRD spectrum, which indicates that ZnO exists in a highly dispersed or amorphous form in the catalyst. In addition, no diffraction peaks corresponding to Cr, Al and Ga are observed in the XRD spectrum of the catalyst, which further indicates that the structural additive exists in a highly dispersed or encapsulated form in the ZnO matrix.

[0081] Figure 3 (a1-d1, a3-d3) are TEM images of the catalysts and the corresponding Cu particle size histograms. The black spherical nanoparticles in the catalysts correspond to Cu, and the average particle sizes of Cu in the CZ, CZAC, CZCG and CZAG catalysts are 29.4 nm, 29.1 nm, 28.5 nm and 48.2 nm, respectively. The results show that the analysis results of TEM and XRD are not much different and the variation trend of Cu particle size is the same, which indicates that there is no essential difference between the two conclusions. In addition, the lattice fringes with lattice spacing of approximately 0.21 nm and 0.25 nm correspond to the Cu (111) and ZnO (101) crystal planes, respectively, and the interface between them can be clearly observed, indicating that there is an interaction between Cu / ZnO, which is conducive to the formation of catalytic active sites in the process of CO hydrogenation to ethanol [ Figure 3 (a2-d2)].

[0082] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a doped Cu-based catalyst, characterized in that: The steps include: S1. Dispersing mesoporous silica into a toluene solution containing 3-aminopropyltrimethoxysilane, heating to 50-90° C., reflux reaction for 5-10 hours, then filtering, washing with sufficient toluene, and drying at low temperature to obtain pretreated mesoporous silica; S2, soaking the pretreated mesoporous silica obtained in step S1 in a 0.5-1 mol / L zinc nitrate solution for 3-8 hours, and then filtering to obtain mesoporous silica loaded with zinc ions; S3, soaking the mesoporous silica loaded with zinc ions obtained in step S2 in ammonia water with a pH of 8-10 for 1-4 hours, then filtering, placing the filtered product in a muffle furnace and calcining it at 600-800° C. for 2-5 hours to obtain mesoporous silica loaded with zinc oxide; S4, placing the zinc oxide-loaded mesoporous silica obtained in step S3 into a 0.1-0.5% by mass EDTA aqueous solution, heating it to 40-60° C. for reaction for 3-6 hours, and then filtering to obtain a filtrate; S5. The filtrate obtained in step S4 is placed in a mixed solution of copper nitrate and a structural additive and soaked for 1-2 hours, then sodium carbonate is added to adjust the pH to 8-9, and filtered to obtain a crude product; S6. The crude product obtained in step S5 is placed in a sodium hydroxide solution with a concentration of 4-6 mol / L, heated to 60-80° C. and reacted for 1-3 h, and then filtered. The filtered product is washed with sufficient deionized water and dried at 60-100° C. The dried product is placed in a muffle furnace and reduced at 200-300° C. in a hydrogen and nitrogen atmosphere for 2-4 h to obtain a doped Cu-based catalyst after reduction; In step S5, the concentration of copper nitrate is 0.1-0.4 mol / L, the mass ratio of the filtrate to the mixed solution of copper nitrate and a structural additive is 1:(20-30), and the structural additive is a combination of any two metal salts of Al, Ga or Cr; The metal salt contained in the structural auxiliary agent is specifically aluminum nitrate, gallium nitrate or chromium nitrate, and the concentration of the structural auxiliary agent is 0.005 mol / L.

2. The method for preparing a doped Cu-based catalyst according to claim 1, wherein: In step S1, the mass ratio of silicon dioxide, 3-aminopropyltrimethoxysilane and toluene is 1:(0.1-0.5):(50-60).

3. The method for preparing a doped Cu-based catalyst according to claim 1, wherein: In step S2, the mass ratio between the pretreated mesoporous silica and the zinc nitrate solution is 1:(30-50).

4. The method for preparing a doped Cu-based catalyst according to claim 1, wherein: In step S3, the mass ratio between the mesoporous silica loaded with zinc ions and the ammonia solution is 1:(10-20).

5. The method for preparing a doped Cu-based catalyst according to claim 1, wherein: In step S4, the mass ratio between the mesoporous silica loaded with zinc oxide and the EDTA aqueous solution is 1:(70-100).

6. The method for preparing a doped Cu-based catalyst according to claim 1, wherein: In step S6, the mass ratio of the crude product to the sodium hydroxide solution is 1:(50-100), and the volume ratio of the hydrogen to the nitrogen is 1:

4.

7. A doped Cu-based catalyst, characterized in that: The catalyst is prepared by the method for preparing the doped Cu-based catalyst according to any one of claims 1 to 6.

8. Use of the doped Cu-based catalyst as claimed in claim 7 in synthesizing ethanol.

Images