Copper-based island catalyst synergistically modified by MTW-MFI eutectic molecular sieve and CeO2 as well as preparation method and application of copper-based island catalyst

Abstract

The invention discloses an MTW-MFI eutectic molecular sieve and CeO2 synergistically modified copper-based island catalyst and a preparation method and application thereof.The preparation method comprises the steps that S1, organic front salt serves as a cerium source and is dissolved in an organic solvent, and a cerium precursor solution is obtained; dropwise adding the mixed solution into an MTW-MFI eutectic molecular sieve, so that the solution is just completely absorbed by the MTW-MFI eutectic molecular sieve; treating the obtained sample at 60-100 DEG C for 1-12 hours to remove the organic solvent, and roasting for 1-30 hours to obtain a precursor; s2, dispersing the precursor in water, adding copper salt and a proper amount of alkali source, stirring to deposit copper in the CeOx / MTW-MFI precursor, then separating, washing, drying, and roasting at 400-800 DEG C for 2-50 hours to obtain the target catalyst. A Cu-CeO2 nano active interface is constructed, an island catalyst is formed, and the problems of activity, stability and selectivity of a copper-based catalyst in an MSR reaction are solved.

Description

[0001] This invention relates to the field of catalyst materials, specifically to a copper-based island catalyst synergistically modified by MTW-MFI eutectic molecular sieve and CeO2, its preparation method, and its application. Technical Background

[0002] Methanol reforming (MSR) is a key pathway for efficiently obtaining high-purity hydrogen, demonstrating significant potential in distributed energy and mobile fuel cell applications. This process operates under relatively mild conditions and uses liquid methanol as a feedstock, circumventing major safety and cost bottlenecks in hydrogen storage and transportation. Therefore, it is considered a crucial bridge connecting the renewable methanol economy with hydrogen energy utilization. Among various catalytic systems, copper-based catalysts have long been central to the industrial application and academic research of this reaction due to their excellent selectivity for the target product carbon dioxide and their relatively low cost. However, the inherent thermal stability of copper-based catalysts—the tendency for active copper species to sinter and aggregate during long-term reactions, leading to a decrease in the number of active sites and rapid catalyst deactivation—remains a core challenge restricting their large-scale application.

[0003] Chinese patent document CN120914322A discloses a symbiotic molecular sieve of MTW and MFI, which has a chemical composition as shown in the formula "SiO2·1 / nAl2O3·pR", where 50≤n≤80 and 0.04. The method for preparing the symbiotic molecular sieve includes mixing a silicon source, sodium aluminate, sodium hydroxide, an organic structure directing agent, and water, crystallizing, filtering, washing, and drying to obtain the symbiotic molecular sieve; wherein, the content of Al2O3 in the sodium aluminate is 35%-43% by weight, preferably 38%-43%, and the content of Na2O is 25%-33% by weight, preferably 28%-33%; the organic structure directing agent is selected from at least one of methyltriethylammonium hydroxide, methyltriethylammonium chloride, methyltriethylammonium bromide, and methyltriethylammonium iodide; the molar ratio of the silicon source (SiO2), sodium aluminate (Al2O3), sodium hydroxide, organic structure directing agent (methyltriethylammonium ions), and water is 1:0.012-0.020:0.15-0.25:0.07-0.12:10-50. The existing technology only involves the synthesis method and chemical composition of MTW-MFI symbiotic molecular sieves, and does not involve CeO2 modification and the construction of copper-based island catalysts.

[0004] Chinese patent document CN117985732A discloses a copper-based molecular sieve catalyst and its preparation method. This catalyst uses ZSM-5 molecular sieve as a support and loads copper active components via ion exchange for CO oxidation. The preparation process involves mixing and stirring ZSM-5 molecular sieve with a copper nitrate solution, followed by drying and calcination to obtain the copper-based catalyst. This prior art uses a single ZSM-5 molecular sieve support and only loads copper components via simple ion exchange. It does not involve the composite structure of MTW-MFI eutectic molecular sieves, nor does it introduce CeO2 for synergistic modification, and it does not construct copper-based island active structures.

[0005] Chinese patent document CN119702064A discloses a method for preparing a molecular sieve catalyst for the synergistic removal of CO and NO under medium and low temperature conditions and its application. The method involves dissolving copper and cerium salts in water to prepare a mixed solution; adding a β-molecular sieve to the mixed solution and stirring until homogeneous; impregnating the solution under water bath heating conditions; and then drying and calcining to obtain a CuCe / β-molecular sieve catalyst. This prior art has a simple preparation process and low raw material cost. When used in industries such as steel, cement, and petrochemicals to remove nitrogen oxides (NOx) and CO pollutants from industrial flue gas, it exhibits good catalytic activity, a wide temperature window, and high N2 selectivity. Within the temperature range of 200–350℃, the NO conversion rate can reach 90%, the CO conversion rate can reach 99%, and the N2 selectivity can reach 95%. Although the existing technology involves the combination of copper-cerium dual components and molecular sieves, it uses a single β molecular sieve as a carrier and does not construct a eutectic composite structure of MTW and MFI molecular sieves, thus failing to achieve the synergistic mass transfer effect of different pore systems. The active components are loaded by a simple water bath impregnation method, without involving the precise control of the copper-based island structure, making it difficult to solve the problem of high-temperature agglomeration of the active components.

[0006] To address the aforementioned issues, it is necessary to propose a method for preparing and applying a copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a method for preparing and applying a copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2. MTW-MFI eutectic molecular sieve is selected as the carrier for copper species, and cerium oxide (CeO2) is introduced as a key electronic and structural aid to construct a "Cu-CeO2 nano-active interface," forming an island catalyst. The synergistic modification of the copper-based catalyst by the eutectic molecular sieve and CeO2 solves the problems of activity, stability, and selectivity of copper-based catalysts in the MSR reaction.

[0008] To address the aforementioned technical problems, a first aspect of the present invention provides a method for preparing a copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2, specifically comprising the following steps:

[0009] S1: Using an organic presalt as the cerium source, it is dissolved in an organic solvent to obtain a cerium precursor solution; then the cerium precursor solution is slowly added dropwise to the MTW-MFI eutectic molecular sieve, so that the solution is just completely absorbed by the MTW-MFI eutectic molecular sieve, and allowed to stand for 1-30 hours; the obtained sample is treated at 60-100℃ for 1-12 hours to remove the organic solvent, and finally subjected to programmed temperature calcination for 1-30 hours to obtain the CeOx / MTW-MFI precursor;

[0010] S2: Disperse the obtained CeOx / MTW-MFI precursor in water, add copper salt and alkali source, stir at 40-90℃ to allow copper to deposit in CeOx / MTW-MFI precursor, then separate, wash, dry, and calcine at 400-800℃ for 2-50h to obtain the target catalyst.

[0011] Using the above technical solution, MTW-MFI eutectic molecular sieve is selected as the carrier for copper species. MTW-MFI eutectic molecular sieve possesses unique advantages in metal carriers due to its regular pore structure, tunable acid properties, and good hydrothermal stability. As a porous material with a symbiotic topological structure, MTW-MFI eutectic molecular sieve overcomes the limitations of single molecular sieves in pore configuration and acidity distribution. This material combines the three-dimensional cross-channels of MFI with the one-dimensional through-channels of MTW, forming a unique crystal phase interface and pore network, which helps improve the dispersion of copper species and inhibit sintering, while also improving the transformation of reaction intermediates. Furthermore, by regulating the MTW-MFI eutectic framework, an appropriate amount of weak acid sites can be retained to anchor copper species while reducing the acidity of the carrier surface, thereby improving reactivity and product selectivity. Simultaneously, cerium oxide (CeO2) is introduced as a key electronic and structural agent to optimize the active center environment. The addition of CeO2 serves two purposes. First, its abundant oxygen vacancies act as anchoring sites, stabilizing copper ions and their oxide nanoclusters and further enhancing dispersion. Second, the reversible redox properties of CeO2 can efficiently regulate the transfer and supply of reactive oxygen species during the reaction. By changing the amount of Ce added, precise control can be achieved over the chemical state of copper species, electron transfer at the support-metal interface, and the concentration of surface hydroxyl groups.

[0012] Preferably, the organic presalt in step S1 is a cerium salt, selected from cerium tetraisopropoxy and / or cerium acetylacetone; the organic solvent is at least one or more of anhydrous toluene, anhydrous xylene, and anhydrous n-hexane; the mass ratio of the cerium salt to the volume of the organic solvent is 1:0.025-1:50 mg / mL.

[0013] Preferably, in step S1, the specific surface area of ​​the MTW-MFI eutectic molecular sieve used is 200~700 m². 2 / g, pore volume in the range of 0.20~0.46cm³ 3 / g.

[0014] Preferably, in step S1, a programmed temperature rise is used for calcination, with a programmed temperature rise rate of 1-10℃ / min. First, calcination is carried out at 300℃ for 1-6 hours; then, the temperature is raised to 400-700℃ for 1-30 hours.

[0015] Preferably, in step S1, a programmed temperature rise is used for calcination, with a programmed temperature rise rate of 1-4℃ / min. First, calcination is carried out at 300℃ for 2-4 hours; then, the temperature is raised to 400-700℃ for 4-15 hours.

[0016] Preferably, in step S2, the copper salt is one or more of copper nitrate, copper acetate, copper chloride, copper carbonate, and copper sulfate; the alkali source is urea and / or ammonium carbonate; the mass ratio of copper salt to water volume is 1:0.1-1:100 mg / mL, and the concentration of the alkali source solution is 0.05-1.5M.

[0017] Preferably, in step S2, the mass ratio of CeOx / MTW-MFI precursor to water is (1:3) to (1:100); the copper deposition time is 0.5-24 h; the drying temperature is 80-150 °C; and the drying time is 5-24 h.

[0018] A second aspect of the present invention is to provide a copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2 as described in the first aspect of the present invention, wherein the mass ratio of Cu to the total weight of the catalyst is (0.005~0.6):1; and the mass ratio of Ce to CeOx / MTW-MFI precursor is (0.005~0.8):1.

[0019] A third aspect of the present invention is to provide an application of the MTW-MFI eutectic molecular sieve and CeO2 synergistically modified copper-based island catalyst as described in the second aspect of the present invention in the methanol reforming hydrogen production reaction.

[0020] Preferably, in the method for producing hydrogen, the MTW-MFI eutectic molecular sieve and the CeO2-modified copper-based island catalyst are placed in a catalyst bed, using an alcohol-containing substance as raw material, with a reaction temperature of 120-400℃, a reaction pressure of 0.1-10.0 MPa, and an alcohol mass hourly space velocity of 1-30 h⁻¹. -1 Under certain conditions, the mixture comes into contact with the catalyst bed and reacts to produce products containing hydrogen.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) This invention uses MTW-MFI eutectic molecular sieve and introduces cerium oxide (CeO2) as a key electronic and structural aid to construct a "Cu-CeO2 nano-active interface" to form an island structure catalyst. This results in a copper-based island catalyst synergistically modified by MTW-MFI eutectic molecular sieve and CeO2, which effectively solves the technical problems of uneven dispersion and easy migration and sintering of active Cu species in the catalyst.

[0023] (2) The method for preparing copper-based island catalyst synergistically modified by MTW-MFI eutectic molecular sieve and CeO2 provided by the present invention improves the problems of complex preparation process and inaccurate catalyst interface construction of traditional catalysts.

[0024] (3) The copper-based island catalyst provided is simple and easy to prepare, and has low cost. It improves the conversion rate of raw alcohol, hydrogen selectivity and catalyst stability in the alcohol hydrogen production reaction, and has very good industrial application value.

[0025] In summary, this invention synergistically designs the confinement effect of MTW-MFI eutectic molecular sieves with the tunable redox capability of CeO2. Through a controllable preparation process, CeO2 is preferentially modified within the pores of the molecular sieve support and around copper species, ultimately constructing a "Cu-CeO2 nano-active interface" to form island catalysts. This systematically improves the problem of balancing activity and stability in copper-based catalysts during the MSR reaction. This design strategy not only provides a new direction for the development of efficient hydrogen production catalysts but also has important reference value for understanding the complex synergistic mechanisms between metals, oxides, and supports in heterogeneous catalysis. Attached Figure Description

[0026] Figure 1 The image shows the XRD pattern of the copper-based island catalyst synergistically modified with CeO2 by the MTW-MFI eutectic molecular sieve prepared in this invention; the Cu loading in the image is 5%.

[0027] Figure 2 SEM images of the copper-based island catalyst synergistically modified with CeO2 by the MTW-MFI eutectic molecular sieve prepared in this invention are shown below; (a) CeO2 support; (b) MTW-MFI support; (c) enlarged view of MTW-MFI support; (d) Cu / CeO2; (e) Cu / MTW-MFI; (f) Cu5Ce / MTW-MFI. Detailed Implementation

[0028] The specific embodiments of the present invention will be described in detail below, but the present invention is not limited thereto.

[0029] Unless otherwise specified, the preparation methods and usage conditions used in the following examples are conventional methods; unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0030] To avoid excessive and unnecessary detail, well-known structures or functions will not be described in detail in the following embodiments. The approximate language used in the following embodiments is for quantitative purposes, indicating that variations in quantity are permissible without altering the basic function. Unless otherwise defined, the technical and scientific terms used in the following embodiments have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0031] Example 1: The preparation method of the copper-based island catalyst synergistically modified by the MTW-MFI eutectic molecular sieve and CeO2 is as follows:

[0032] S1: Weigh 300 mg of cerium tetraisopropoxy and dissolve it in 10 mL of anhydrous toluene to obtain a cerium solution. Then, slowly add the solution dropwise to 2 g of MTW-MFI eutectic molecular sieve, so that the cerium solution is just completely absorbed by the molecular sieve. Let it stand for 12 h, and then vacuum dry the obtained sample at 80 °C for 8 h to remove the organic solvent. Finally, calcinate the sample by first heating it to 300 °C at 1 °C / min for 2 h, and then heating it to 600 °C for 4 h to obtain the CeOx / MTW-MFI precursor.

[0033] S2: To prepare the Cu5Ce5 / MTW-MFI catalyst, 2g of the obtained CeOx / MTW-MFI precursor was dispersed in water (CeOx / MTW-MFI to water mass ratio of 1:50). 0.38g of copper nitrate hexahydrate was added, and after complete dissolution, urea was added to adjust the pH of the solution to 9. The mixture was stirred at 80 °C for 6 h to deposit and age, then filtered, washed with water, and dried at 100 °C for 12 h. Finally, it was calcined at 550 °C for 5 h to obtain the copper-based catalyst synergistically modified by MTW-MFI eutectic molecular sieve and CeO2, denoted as Cu5Ce5 / MTW-MFI.

[0034] The specific surface area of ​​the MTW-MFI molecular sieve used above was found to be 480 m². 2 / g, pore volume is 0.28cm³ 3 / g; the obtained Cu5Ce5 / MTW-MFI catalyst contains 5% Cu by mass and 5% Ce by mass; the specific surface area of ​​the catalyst is 420m². 2 / g, pore volume in 0.35cm³ 3 / g.

[0035] Example 2: The difference from Example 1 is that the content of cerium tetraisopropoxy is 0.56g when preparing the precursor in step S1; the rest is the same as in Example 1; in step S2, 0.38g of copper nitrate hexahydrate is weighed to obtain a Cu5Ce9 / MTW-MFI catalyst with a Cu loading of 5% and a Ce loading of 9%.

[0036] The specific surface area of ​​the MTW-MFI eutectic molecular sieve used above was tested to be 480 m². 2 / g, pore volume 0.28 cm³ 3 / g; the obtained Cu5Ce9 / MTW-MFI catalyst contains 5% Cu by mass and 9% Ce by mass; the specific surface area of ​​the catalyst is 403 m² / g. 2 / g, pore volume in 0.32 cm³ 3 / g.

[0037] Example 3: The difference from Example 1 is that the content of cerium tetraisopropoxy is 0.42g when preparing precursor A in step S1; the rest is the same as in Example 1; in step S2, 0.38g of copper nitrate hexahydrate is weighed to obtain Cu5Ce7 / MTW-MFI catalyst with Cu loading of 5% and Ce loading of 7%.

[0038] The specific surface area of ​​the MTW-MFI eutectic molecular sieve used above was tested to be 480 m². 2 / g, pore volume 0.28 cm³ 3 / g; the obtained Cu5Ce7 / MTW-MFI catalyst contains 5% Cu by mass and 7% Ce by mass; the specific surface area of ​​the catalyst is 408 m² / g. 2 / g, pore volume in 0.33 cm³ 3 / g;

[0039] Example 4: The difference from Example 1 is that in step S1, when preparing precursor A, the content of cerium tetraisopropoxy is 0.18g and it is dissolved in 30mL of water; the rest is the same as in Example 1; in step S2, 0.38g of copper nitrate hexahydrate is weighed to obtain Cu5Ce3 / MTW-MFI catalyst with a Cu loading of 5% and a Ce loading of 3%.

[0040] The specific surface area of ​​the MTW-MFI eutectic molecular sieve used above was tested to be 480 m². 2 / g, pore volume 0.28 cm³ 3 / g; the obtained Cu5Ce3 / MTW-MFI catalyst contains 5% Cu and 3% Ce by mass; the specific surface area of ​​the catalyst is 450 m² / g. 2 / g, pore volume is 0.34cm³ 3 / g.

[0041] Comparative Example 1: The preparation method in Comparative Example 1 differs from that in Example 1 in that no molecular sieve MTW-MFI was added; only CeO2 was used as the support. The specific steps are as follows:

[0042] Preparation of CeO2 support (S1): 8.68 g of cerium nitrate hexahydrate was dissolved in 100 mL of deionized water. After complete dissolution, an appropriate amount of ammonia was slowly added dropwise while vigorously stirring the solution. When the pH of the solution reached 9.5-10.0, stirring and aging continued for 2 hours. The precipitate suspension was then sealed and allowed to stand at room temperature for 12 hours. The precipitate was washed with deionized water until the pH reached 7, followed by multiple alcohol washes, and dried overnight at 80°C. Subsequently, the temperature was raised to 550°C and calcined for 4 hours to obtain the CeO2 support.

[0043] Preparation of Cu / CeO2 catalyst (S2): 2g CeO2 was dispersed in water (CeO2 to water mass ratio 1:50), and 0.38g copper nitrate hexahydrate was added. After complete dissolution, urea was added to adjust the pH of the solution to 9. The mixture was stirred at 80°C for 6 h to deposit and age. After filtration, washing with water, and drying at 100°C for 12 h, the CeO2-supported copper-based catalyst was finally obtained by calcination at 550°C for 5 h, denoted as Cu / CeO2.

[0044] The tested Cu / CeO2 catalyst contained 5% Cu by mass; the specific surface area of ​​the catalyst was 80 m². 2 / g, pore volume is 0.21cm³ 3 / g;

[0045] Comparative Example 2: The preparation method in Comparative Example 2 differs from that in Example 1 in that cerium was not added. The specific steps are as follows:

[0046] 2 g of MTW-MFI was dispersed in water (MTW-MFI to water mass ratio of 1:50), and 0.38 g of copper nitrate hexahydrate was added. After complete dissolution, urea was added to adjust the pH of the solution to 9. The mixture was stirred at 80°C for 6 h to deposit and age, then filtered, washed with water, and dried at 100°C for 12 h. Finally, it was calcined at 550°C for 5 h to obtain a copper-based catalyst supported on MTW-MFI eutectic molecular sieve, denoted as Cu5 / MTW-MFI.

[0047] The obtained Cu / MTW-MFI catalyst contains 5% Cu by mass and 0% Ce by mass; the specific surface area of ​​the catalyst is 450 m². 2 / g, pore volume is 0.34cm³ 3 / g.

[0048] Examples 5-30 are provided to explore the optimal preparation parameters.

[0049] Cu m Ce n The MTW-MFI eutectic molecular sieve and CeO2 synergistic modification copper-based island catalyst described in Table 1 can be obtained by following the preparation conditions in Table 1, except for the different designed parameters.

[0050] Table 1. Parameters and performance results of Examples 5-30

[0051] Example Cu loading (%) Ce loading (%) <![CDATA[MTW - MFI specific surface area (m 2 / g)]]> <![CDATA[MTW-MFI pore volume (m 3 / g)]]> MTW-MFI and water mass ratio Cu salt types Ce salt types Catalyst calcination temperature (°C) <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Pore volume (m 3 / g)]]> 5 0.5 15 480 0.28 1:50 Copper nitrate Tetraisopropoxycerium 550 470 0.26 6 1 15 480 0.28 1:50 Copper nitrate Tetraisopropoxycerium 550 460 0.26 7 5 15 480 0.28 1:50 Copper nitrate Tetraisopropoxycerium 550 428 0.24 8 10 15 360 0.35 1:50 Copper nitrate Tetraisopropoxycerium 550 321 0.33 9 10 30 360 0.35 1:50 Copper nitrate Tetraisopropoxycerium 550 335 0.34 10 10 50 360 0.35 1:10 Copper nitrate Tetraisopropoxycerium 550 303 0.33 11 10 80 200 0.20 1:3 Copper sulfate Tetraisopropoxycerium 550 180 0.18 12 0.5 0.5 480 0.28 1:50 Copper nitrate Tetraisopropoxycerium 550 462 0.28 13 15 15 480 0.28 1:50 Copper nitrate Cerium acetylacetonate 550 427 0.25 14 25 25 480 0.28 1:50 Copper nitrate Cerium acetylacetonate 550 403 0.24 15 50 50 480 0.28 1:50 Copper nitrate Cerium acetylacetonate 550 343 0.22 16 60 80 480 0.28 1:50 Copper nitrate Cerium acetylacetonate 550 302 0.20 17 5 5 600 0.36 1:60 Copper acetate Cerium acetylacetonate 550 416 0.35 18 5 5 700 0.46 1:80 Copper acetate Cerium acetylacetonate 400 600 0.42 19 5 5 650 0.39 1:40 Copper nitrate Cerium acetylacetonate 650 581 0.37 20 10 10 550 0.32 1:20 Copper carbonate Cerium acetylacetonate 800 378 0.31 21 10 10 550 0.32 1:45 Copper nitrate Cerium acetylacetonate 400 498 0.32 22 10 10 550 0.32 1:30 Copper nitrate Tetraisopropoxycerium 600 472 0.30 23 5 7 500 0.30 1:70 Copper nitrate Tetraisopropoxycerium 700 382 0.29 24 5 7 370 0.24 1:100 Copper nitrate Tetraisopropoxycerium 450 340 0.22 25 5 7 460 0.28 1:50 Copper chloride Tetraisopropoxycerium 500 446 0.27 26 1 5 240 0.21 1:12 Copper nitrate Tetraisopropoxycerium 550 210 0.20 27 1 5 210 0.20 1:5 Copper nitrate Tetraisopropoxycerium 650 190 0.18 28 1 5 450 0.26 1:50 Copper nitrate Tetraisopropoxycerium 750 403 0.24 29 5 5 450 0.26 1:40 Copper nitrate Tetraisopropoxycerium 400 428 0.22 30 5 5 450 0.26 1:30 Copper nitrate Tetraisopropoxycerium 700 368 0.22

[0052] Table 1 shows that the specific surface area of ​​the catalyst decreases with increasing Cu and Ce loading; this indicates that high Cu loading clogs the support pores, leading to a decrease in specific surface area, but the pore volume is less affected or even slightly increased. Furthermore, Ce loading has a more significant impact on pore structure; high Ce loading not only significantly reduces the specific surface area but also noticeably compresses the pore volume, indicating that Ce species are more likely to fill / collapse the pores. At the same loading, higher calcination temperatures result in a lower specific surface area and a corresponding decrease in pore volume; a larger specific surface area on the MTW-MFI support helps to increase the specific surface area of ​​the prepared catalyst. Additionally, it was found that using copper nitrate as the copper source and cerium tetraisopropoxy as the cerium source helps to disperse the active metal components on the surface of the MTW-MFI support.

[0053] The catalysts prepared in Examples 1-30 and Comparative Examples 1-2 were used in the reaction for hydrogen production from alcohols. The catalyst performance was evaluated according to the reaction conditions in Table 2, and hydrogen-rich products were obtained. The catalysts used in Examples 1-30 in Table 2 correspond to the catalysts used in Examples 1-30 in Table 1.

[0054] Table 2. Catalyst application results in Examples 1-30 and Comparative Examples 1-2

[0055] Catalyst Examples Reduction temperature (°C) Reaction temperature (°C) raw material Water-to-alcohol ratio (mol) Pressure (MPa) Alcohol conversion rate (%) CO selectivity (%) Hydrogen yield (mmol / g / h) 1 Discover 300 Water: Methanol 1.2 0.1 94 0.98 820 2 300 300 Water: Methanol 1.2 0.1 76 0.69 386 3 300 300 Water: Methanol 1.2 0.1 88 0.75 415 4 300 300 Water: Methanol 1.2 0.1 90 0.82 673 5 300 300 Water: Methanol 1.2 0.1 53 0.24 165 6 300 300 Water: Methanol 1.2 0.1 71 0.63 369 7 300 300 Water: Methanol 1.2 0.1 89 0.9 786 8 300 300 Water: Methanol 1.2 0.1 87 0.88 752 9 300 300 Water: Methanol 1.2 0.1 79 0.71 467 10 300 300 Water: Methanol 1.2 0.1 62 0.46 256 11 300 300 Water: Methanol 1.2 0.1 51 0.21 158 12 300 300 Water: Methanol 1.2 0.1 78 0.62 455 13 300 300 Water: Methanol 1.2 0.1 84 0.76 739 14 300 300 Water: Methanol 1.2 0.1 76 0.65 348 15 300 300 Water: Methanol 1.2 0.1 61 0.35 261 16 300 300 Water: Methanol 1.2 0.1 55 0.12 159 17 300 300 Water: Methanol 1.2 3 98 0.95 919 18 300 320 Water: Methanol 1.2 0.5 99 0.95 935 19 300 260 Water: Methanol 1.2 5 90 0.87 783 20 300 280 Water: Methanol 1.8 0.1 74 0.64 325 21 300 300 Water: Methanol 0.8 0.1 87 0.83 743 22 350 300 Water: Methanol 1.5 0.1 82 0.72 715 23 300 280 Water: Methanol 1.2 0.1 85 0.75 694 24 300 280 methanol 0 0.1 70 0.56 349 25 300 320 methanol 0 0.1 81 0.69 623 26 300 300 Water: Ethanol 1.2 0.1 66 0.48 288 27 200 300 Water: Ethanol 1.5 0.1 53 0.14 150 28 300 350 Water: Ethanol 0.8 0.1 80 0.75 615 29 300 350 ethanol 0 2 85 0.93 779 30 320 300 ethanol 0 0.1 65 0.48 315 Comparative Example 1 300 280 Water: Methanol 1.2 0.1 61 0.12 523 Comparative Example 2 300 280 Water: Methanol 1.2 0.1 67 0.53 586

[0056] Table 2 summarizes the reaction performance of the examples in alcohol-to-hydrogen production. It was found that when the loadings of Cu (0.5-15%) and Ce (0.5-25%) were low, the active component dispersion was good, resulting in better methanol-to-hydrogen performance, achieving a conversion rate of 80-98%, and correspondingly, a higher hydrogen production rate. Reduction temperatures above 300 °C helped improve catalyst conversion. Furthermore, the reaction temperature significantly affected the catalytic performance; lower temperatures resulted in relatively weaker activity, while higher temperatures favored higher alcohol conversion, but were accompanied by higher CO selectivity.

[0057] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0058] For those skilled in the art, the specific embodiments are merely illustrative descriptions of the present invention. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution, such as changing the mass of a substance or a reaction parameter, or directly applying the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A method for preparing a copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2, characterized in that, Specifically, the following steps are included: S1: Using an organic salt as the cerium source, it is dissolved in an organic solvent to obtain a cerium precursor solution; then the cerium precursor solution is added dropwise to the MTW-MFI eutectic molecular sieve, so that the solution is just completely absorbed by the MTW-MFI eutectic molecular sieve, and allowed to stand for 1-30 h; the obtained sample is treated at 60-100℃ for 1-12 h to remove the organic solvent, and finally calcined for 1-30 h to obtain the CeOx / MTW-MFI precursor; S2: Disperse the obtained CeOx / MTW-MFI precursor in water, add copper salt and alkali source, stir at 40-90℃ to allow copper to deposit in CeOx / MTW-MFI precursor, then separate, wash, dry, and calcine at 400-800℃ for 2-50h to obtain the target catalyst.

2. The preparation method of the copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2 according to claim 1, characterized in that, The organic presalt mentioned in step S1 is a cerium salt, selected from cerium tetraisopropoxy and / or cerium acetylacetone; the organic solvent is at least one or more of anhydrous toluene, anhydrous xylene, and anhydrous n-hexane; the mass ratio of the cerium salt to the volume of the organic solvent is 1:0.025-1:50 mg / mL.

3. The preparation method of the copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2 according to claim 1, characterized in that, In step S1, the specific surface area of ​​the MTW-MFI eutectic molecular sieve used is 200~700 m². 2 / g, pore volume in the range of 0.20~0.46cm³ 3 / g.

4. The preparation method of the copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2 according to claim 1, characterized in that, In step S1, a programmed temperature rise is used for calcination. The programmed temperature rise rate is 1-10℃ / min. First, calcination is carried out at 300℃ for 1-6 hours; then, the temperature is raised to 400-700℃ for 1-30 hours.

5. The preparation method of the copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2 according to claim 4, characterized in that, In step S1, a programmed temperature rise is used for calcination. The programmed temperature rise rate is 1-4℃ / min. First, calcination is carried out at 300℃ for 2-4 hours; then, the temperature is raised to 400-700℃ for 4-15 hours.

6. The preparation method of the copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2 according to claim 4, characterized in that, In step S2, the copper salt is one or more of copper nitrate, copper acetate, copper chloride, copper carbonate, and copper sulfate; the alkali source is urea and / or ammonium carbonate; the mass ratio of copper salt to water volume is 1:0.1-1:100 mg / mL, and the concentration of the alkali source liquid is 0.05-1.5M.

7. The preparation method of the copper-based island catalyst synergistically modified with MTW-MFI eutectic molecular sieve and CeO2 according to claim 6, characterized in that, In step S2, the mass ratio of CeOx / MTW-MFI precursor to water is (1:3) to (1:100); the copper deposition time is 0.5-24 h; the drying temperature is 80-150 ℃; and the drying time is 5-24 h.

8. A copper-based island catalyst synergistically modified with CeO2 as described in any one of claims 1-7, characterized in that, The mass ratio of Cu to the total weight of the catalyst is (0.005~0.6):1; the mass ratio of Ce to CeOx / MTW-MFI precursor is (0.005~0.8):

1.

9. The application of the MTW-MFI eutectic molecular sieve and CeO2 synergistic modified copper-based island catalyst as described in claim 8 in the methanol reforming hydrogen production reaction.

10. The application according to claim 9, characterized in that, The method for producing hydrogen involves placing the MTW-MFI eutectic molecular sieve and a CeO2-modified copper-based island catalyst in a catalyst bed, using an alcohol-containing substance as raw material, at a reaction temperature of 120-400℃, a reaction pressure of 0.1-10.0 MPa, and an alcohol mass hourly space velocity of 1-30 h⁻¹. -1 Under certain conditions, the mixture comes into contact with the catalyst bed and reacts to produce products containing hydrogen.

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