Ce-MOF-derived multi-metal oxide / ZSM-5-based composite catalyst as well as preparation method and application thereof

Abstract

The invention discloses a Ce-MOF derived multi-metal oxide / ZSM-5-based composite catalyst as well as a preparation method and application thereof, and belongs to the technical field of aviation kerosene preparation. The H-ZSM-5 molecular sieve is synthesized by adopting a hydrothermal method, and Ce-MOF is grown on the surface of the H-ZSM-5 molecular sieve in situ. The high specific surface area, developed pore structure and abundant unsaturated sites of the Ce-MOF material are utilized to realize efficient loading of various active metals. And drying and calcining to obtain the Ce-MOF derived multi-metal oxide / ZSM-5 composite catalyst with a stable structure. Rich oxygen vacancies and active sites can efficiently activate CO2 molecules and promote the hydrogenation process of the CO2 molecules and H2 to generate a key methanol intermediate; accurate carbon chain growth regulation coupling effect can be performed on the methanol intermediate, and the methanol intermediate is quickly and effectively converted. The catalyst prepared by the method provided by the invention has a regular pore structure and suitable acidic sites, and on the basis of the cage control shape selective catalysis principle of the H-ZSM-5 molecular sieve, the per-pass conversion rate of CO2 exceeds 25%, the selectivity of aviation kerosene components in hydrocarbon products reaches 70.5%, and the generation of methane by-products is effectively inhibited.

Description

Technical Field

[0001] This invention belongs to the field of aviation kerosene preparation technology, specifically relating to Ce-MOF-derived polymetallic oxide / ZSM-5 based composite catalysts, their preparation methods, and applications. Background Technology

[0002] Aviation kerosene (mainly composed of C8~C) is synthesized directly by hydrogenating carbon dioxide. 16 The long-chain hydrocarbon (LCH) technology route is widely regarded as one of the most promising key technologies for achieving deep decarbonization in aviation transportation due to its wide availability of raw materials (direct utilization of CO2 from industrial emissions or atmospheric capture) and significant carbon closure potential (achieving carbon resource recycling). However, efficiently and selectively converting inert CO2 molecules into aviation kerosene components of specific chain lengths faces multiple severe technical challenges, necessitating the development of high-performance, long-life catalyst systems to overcome existing bottlenecks.

[0003] Current technologies for the hydrogenation of carbon dioxide to produce aviation kerosene face several key bottlenecks: lack of product selectivity, and the limited effectiveness of traditional catalysts (such as Fe and Co-based systems) on the target product C8-C6. 16Long-chain hydrocarbons generally exhibit low selectivity, and byproducts (such as methane and short-chain alkanes) account for an excessively high proportion, making it difficult to meet the component requirements of aviation fuel. The reaction conditions are demanding, requiring high temperatures (above 300°C) and high pressures (above 3 MPa), leading to a surge in energy consumption and equipment costs. Catalyst stability is insufficient, and catalysts are prone to deactivation due to metal sintering or carbon deposition. Furthermore, the complex reaction pathways and thermodynamic limitations, involving multiple steps such as reverse water-gas shift (CO2→CO), Fischer-Tropsch synthesis (CO→alkanes), and CC coupling, mean that the accumulation of intermediate products (such as CO and olefins) can easily trigger thermodynamic equilibrium limitations, resulting in low overall conversion rates. These intertwined challenges severely restrict the progress of CO2 hydrogenation technology for producing aviation kerosene from the laboratory to large-scale industrial application. Existing metal oxide-molecular sieve composite catalysts significantly outperform traditional single catalysts by integrating the hydrogenation activity of metal oxides with the shape-selective catalytic function of molecular sieves. Their dual-function synergy allows for the cascaded reaction of CO2 hydrogenation and CC coupling, increasing the selectivity of long-chain hydrocarbons to over 50%. The microporous structure of the molecular sieve optimizes the mass transfer pathway, reducing side reactions caused by intermediate product desorption. Simultaneously, the molecular sieve framework partially anchors metal particles, delaying sintering deactivation and extending lifespan. However, these composite catalysts are mostly prepared through physical-mechanical mixing (CN109012743 A). Physical mixing makes it difficult to achieve atomic / molecular-level close contact between the metal oxide and the molecular sieve; the interface relies mainly on weak physical forces. Furthermore, the dispersion of active sites is low, and metal particles are prone to agglomeration. Stability concerns remain; although metal particles are surrounded by the molecular sieve under physical mixing, the anchoring effect is limited, and the risk of sintering and carbon deposition remains high under long-term, harsh reaction conditions.

[0004] To address the problems of weak interfacial contact, low dispersion of active sites, and insufficient long-term stability in existing metal oxide-molecular sieve composite catalysts caused by physical-mechanical mixing, there is an urgent need to find a new metal oxide-molecular sieve composite catalyst and its preparation method to achieve close atomic / molecular contact and chemical bonding between the metal oxide and the molecular sieve framework, thereby improving catalytic performance and stability. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalysts, their preparation methods and applications, so as to solve the technical problems of weak interfacial contact, low dispersion of active sites and insufficient long-term stability of existing metal oxide-molecular sieve composite catalysts due to physical and mechanical mixing.

[0006] To achieve the above objectives, the present invention employs the following technical solution: This invention discloses a method for preparing a Ce-MOF-derived multimetal oxide / ZSM-5-based composite catalyst, comprising: 1) A silicon source, aluminum source, template agent, alkaline solution and deionized water are mixed and stirred to form a uniform gel. After aging, hydrothermal crystallization, washing with water until neutral, first drying, and first high-temperature calcination, sodium molecular sieve is obtained. Sodium molecular sieve is mixed and stirred with NH4NO3 solution; after repeated exchange once, centrifugation and washing until nitrate is free, second drying, and second high-temperature calcination, proton-type H-ZSM-5 molecular sieve is obtained. 2) Proton-type H-ZSM-5 molecular sieve, cerium nitrate solution and 1,3,5-BTC solution were stirred and mixed. After the first static in-situ growth, the Ce-MOF was obtained by centrifugation, alcohol washing and first freeze-drying. The Ce-MOF grown in situ on the molecular sieve was dispersed in methanol solution, and methanol solution containing two metal nitrates was added. After sonication and a second static period, the Ce-MOF was centrifuged, freeze-dried a second time, calcined, ground, pressed into tablets and granulated to obtain Ce-MOF-derived multimetal oxide / ZSM-5-based composite catalyst.

[0007] Preferably, in step 1), the molar ratio of silicon source, aluminum source, template agent, alkaline solution and deionized water is 1:(0.016~0.0025):0.25:0.05:30; The silicon source is SiO2; the aluminum source is sodium aluminate; the template agent is tetrapropylammonium hydroxide; and the alkaline solution is NaOH. The solid-liquid ratio of sodium molecular sieve to NH4NO3 solution is 1:20.

[0008] Preferably, in step 1), the aging time is 2 hours; The conditions for hydrothermal crystallization are: hydrothermal crystallization at 170℃ for 48 hours; The conditions for the first drying were: drying at 100℃ for 12 hours; The conditions for the first high-temperature calcination were: heating to 560℃ at a heating rate of 2℃ / min and calcining at high temperature for 10 hours; The mixing conditions were: mixing at 80℃ for 2 hours; The conditions for the second drying were: drying at 100℃ for 10 hours; The conditions for the second high-temperature calcination were: calcination at 560℃ for 6 hours.

[0009] Preferably, in step 2), the molar ratio of cerium nitrate solution to 1,3,5-BTC solution is 1:1 to 1:2.

[0010] Preferably, in step 2), the first settling time is 2 hours; The centrifugation conditions were: centrifuge at 3000 rpm for 5 minutes; The ultrasound duration is 1-60 minutes; The second settling time is 20-90 minutes; The temperature for both the first and second freeze-drying processes was -50℃, and the time was 12 hours for each process. The calcination temperature is 300~600℃, and the calcination time is 4~8h; The granulation particle size is 60-80 mesh.

[0011] The present invention also discloses a Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst, which is prepared by the above-mentioned method for preparing Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst. The Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst comprises Ce-MOF-derived polymetallic oxide and molecular sieve H-ZSM-5. Ce-MOF-derived polymetallic oxides are used for the efficient conversion of carbon dioxide into methanol intermediates; Molecular sieve H-ZSM-5 utilizes its cage-controlled shape-selective catalytic properties to catalyze the C-C bond coupling reaction of methanol intermediates to synthesize aviation kerosene components.

[0012] Preferably, the Ce-MOF-derived polymetallic oxide is formed by stepwise loading of one or two transition metals from Zn, Ga, Cr, Mn and In using Ce-MOF as a precursor.

[0013] Preferably, in molecular sieve H-ZSM-5, the molar ratio of Si to Al is 30~200.

[0014] This invention also discloses the application of the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst prepared by the above-mentioned method in the catalytic hydrogenation of CO2 to produce aviation kerosene. The Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst is mixed with quartz sand and placed in the isothermal zone of a fixed-bed reactor for evaluation of the catalytic reaction of CO2 catalytic hydrogenation to produce aviation kerosene.

[0015] Preferably, the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst is activated before being used in the catalytic hydrogenation of CO2 to produce aviation kerosene. The activation conditions are: activation at 350°C for 2 hours in hydrogen. The mass ratio of Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst to quartz sand is 1:4; The reaction conditions for the catalytic hydrogenation of CO2 to produce aviation kerosene include: a temperature of 280–360 °C, a reaction pressure of 3–5 MPa, and a mass hourly space velocity of 2400–12000 mL g. cat-1 h -1 H2 / CO2 = 3:1.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a method for preparing a Ce-MOF-derived multimetal oxide / ZSM-5-based composite catalyst. Using the highly ordered porous structure and abundant coordination unsaturated sites of Ce-MOF as an ideal support precursor, the target transition metal is introduced into the Ce-MOF framework or channels in atomic-level or highly dispersed ionic form, ensuring a uniform distribution of the genus species. This modified Ce-MOF precursor is calcined under a controlled atmosphere. The Ce-MOF framework is transformed into a CeO2 matrix with a high specific surface area and rich in oxygen vacancies, while the highly dispersed transition metal ions are simultaneously transformed into metal oxides, uniformly and firmly embedded in the CeO2 lattice or highly dispersed on its surface. Ultimately, the composite catalyst exhibits excellent catalytic performance in a fixed-bed reactor (…). P =3MPa, T =360℃, GHSV=6000 h -1 In this catalyst, a single-pass CO2 conversion rate of 27.8% was achieved, and C8-C 16 The catalyst exhibits a straight-chain alkane selectivity of 64.2% (GC-MS quantitative analysis) and a CH4 selectivity consistently below 10%. It demonstrates excellent reaction stability (>500 h), a simple preparation process, low raw material costs, and ease of scale-up production, providing an efficient technological solution for CO2 resource utilization and green aviation fuel production. The in-situ synthesis method of combining metal oxides and molecular sieves enables close atomic / molecular-level contact and chemical bonding between the metal oxides and the molecular sieve framework. This tight bond promotes strong interactions between components, potentially generating new interfacial active sites or synergistic effects.

[0017] This invention also discloses a Ce-MOF-derived multimetal oxide / ZSM-5-based composite catalyst prepared by the above-mentioned method. This catalyst possesses a high specific surface area and abundant oxygen vacancies. Ce-MOF is calcined into mesoporous CeO2 nanocrystals, exhibiting a superior structure compared to metal oxide aggregates obtained by traditional impregnation methods. Rich in oxygen vacancies, it can efficiently adsorb and activate CO2. The metal oxides are uniformly dispersed and tightly bound. Through MOF topological confinement, transition metals are distributed in atomic-level or highly dispersed ionic form, forming an atomically homogeneous metal oxide solid solution after calcination. Simultaneously, the metal oxides and molecular sieves are tightly bound by chemical bonds (such as Si-O-Ce), preventing the active phase from detaching. The MOF-derived mesoporous structure reduces mass transfer resistance, improves reaction efficiency, and reduces carbon deposition. In a fixed-bed reactor, the CO2 single-pass conversion reaches 27.8%, with C8~C... 16The selectivity for straight-chain alkanes (the main component of aviation kerosene) reached 64.2%, while the selectivity for byproducts such as CH4 was less than 10%. CeO2 oxygen vacancies and transition metals synergistically activated CO2 and H2, and the synergistic effect of multiple metals further improved the yield of the target product. Molecular sieve confinement inhibited high-temperature migration and sintering of metal oxides, and the mesoporous structure optimized mass transfer and reduced carbon deposition. The oxygen storage and release capabilities of CeO2 oxygen vacancies and multi-metal solid solutions can be improved by dynamically redox cycles to repair active sites.

[0018] This invention also discloses the application of the Ce-MOF-derived multimetal oxide / ZSM-5-based composite catalyst prepared by the above method in the catalytic hydrogenation of CO2 to produce aviation kerosene, achieving a single-pass CO2 conversion rate of 27.8%, far exceeding the conversion efficiency of traditional catalysts, providing an efficient pathway for the resource utilization of CO2. It also discloses the directional generation of C8~C... 16 Straight-chain alkanes (the core component of aviation kerosene) are produced with a selectivity of up to 70.5%, and the byproduct CH4 selectivity is <10%, reducing product separation costs. The catalyst is stable, reducing the cost of frequent catalyst replacements and making it suitable for continuous industrial production. The preparation process uses low-cost raw materials, is simple to operate, and is easy to scale up, demonstrating potential for industrial application. It converts CO2 into high-value-added aviation kerosene, reducing carbon emissions and contributing to the construction of a green energy system. This breakthrough overcomes the limitations of traditional CO2 hydrogenation products, which are mainly low-carbon hydrocarbons, providing a new technological solution for the green preparation of aviation fuel. Detailed Implementation

[0019] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined to form new technical solutions.

[0021] Unless otherwise specified, all the technical features and preferred features mentioned herein can be combined to form new technical solutions.

[0022] In this invention, unless otherwise specified, percentage (%) or parts refer to weight percentage or parts relative to the composition.

[0023] In this invention, unless otherwise specified, the components involved or their preferred components can be combined to form new technical solutions.

[0024] In this invention, unless otherwise specified, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "6~22" indicates that all real numbers between "6~22" have been listed in this document, and "6~22" is simply a shortened representation of these numerical combinations.

[0025] The "scope" disclosed in this invention can be in the form of a lower limit and an upper limit, and can be one or more lower limits and one or more upper limits, respectively.

[0026] In this invention, the term "and / or" as used herein refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0027] In this invention, unless otherwise stated, the various reactions or operation steps may be performed sequentially or in a particular order. Preferably, the reaction methods described herein are performed sequentially.

[0028] Unless otherwise stated, the technical and scientific terms used herein have the same meanings as those familiar to those skilled in the art. Furthermore, any methods or materials similar to or equivalent to those described herein may also be used in this invention.

[0029] This invention discloses a Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst, comprising Ce-MOF-derived polymetallic oxide and molecular sieve H-ZSM-5, wherein the metal oxide is grown in situ within the molecular sieve channels; wherein the Ce-MOF-derived polymetallic oxide is used for the efficient conversion of carbon dioxide into methanol intermediate, and the molecular sieve H-ZSM-5 utilizes its cage-controlled shape-selective catalytic properties to catalyze the C-C bond coupling reaction of methanol intermediate to synthesize aviation kerosene components.

[0030] Ce-MOF-derived polymetallic oxides use Ce-MOF as a precursor and form composite metal oxides by stepwise loading of one or two transition metals (Zn, Ga, Cr, Mn, In). The components of the composite metal oxides include two of CeO2, ZnO, Ga2O3, Cr2O3, In2O3, and Mn2O3.

[0031] Molecular sieve H-ZSM-5 was synthesized by a hydrothermal method, with a silicon / aluminum molar ratio of Si / Al = 30~200.

[0032] This invention also discloses a method for preparing a Ce-MOF-derived multimetal oxide / ZSM-5-based composite catalyst, comprising the following steps: 1) Synthesis of proton-type H-ZSM-5 molecular sieve: First, a molecular sieve precursor solution was prepared using silica sol and sodium aluminate as silica-alumina sources and tetrapropylammonium hydroxide as a template agent. This solution was mixed with alkaline solution and deionized water to form a homogeneous gel, which became the molecular sieve precursor solution. After aging for 2 hours, the gel was transferred to a high-pressure reactor for hydrothermal crystallization (170℃, 48 hours). The product was washed with deionized water until neutral, dried at 100℃ for 12 hours, and then calcined at 560℃ for 10 hours (heating rate 2℃ / min) to remove the template agent, yielding sodium-type molecular sieve Na-ZSM-5. The calcined Na-ZSM-5 was then mixed with 1 mol / L NH4NO3 solution at a solid-liquid ratio of 1:20 and stirred at 80℃ for 2 hours. During this process, the Na... + by NH4 + Replacement. To further ensure the Na content in the molecular sieve... + Complete replacement, followed by a single exchange, can minimize Na. + The residue was removed by centrifugation and washing until no nitrate was found. The resulting solid product was dried at 100°C for 10 h and then calcined at 560°C for 6 h to obtain proton-type H-ZSM-5 molecular sieve.

[0033] 2) In-situ growth of composite metal oxides: First, a certain amount of molecular sieve is mixed with cerium nitrate solution and 1,3,5-BTC solution, with the molar ratio of cerium nitrate to 1,3,5-BTC being 1:1. After stirring, the mixed solution was allowed to stand for 2 hours for in-situ growth. Then, it was centrifuged at low speed (3000 rpm, 5 min), washed three times with ethanol, and freeze-dried to obtain Ce-MOF grown in situ on molecular sieves. Subsequently, the Ce-MOF grown in situ on molecular sieves was dispersed in 12 mL of methanol solution, and methanol solution containing two metal nitrates, namely zinc nitrate and gallium nitrate, zinc nitrate and chromium nitrate, zinc nitrate and manganese nitrate, and zinc nitrate and indium nitrate, was added. The mixture was ultrasonically treated and allowed to stand. The solid product was separated by centrifugation (3000 rpm, 5 min) and freeze-dried again. Finally, the dried precursor was calcined in air at 450 °C with a heating rate of 2 °C / min for 5 hours. The obtained solid product was re-ground, pressed into tablets and granulated (60-80 mesh) to obtain Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst.

[0034] In step 1), the molar composition of the molecular sieve precursor solution is SiO2: 0.016~0.0025 Al2O3: 0.25 TPAOH: 0.05 NaOH: 30H2O.

[0035] The template agent is tetrapropylammonium hydroxide (TPAOH). In step 2), the molar ratio of cerium nitrate to 1,3,5-BTC is 1:1. The ultrasonic treatment time was 1-60 min; the settling time was 20-90 min; the freeze-drying time was 12 h for both times, and the freeze-drying temperature was -50℃; the calcination temperature was 300-600℃, and the calcination time was 4-8 h.

[0036] The Ce-MOF-derived polymetallic oxide / ZSM-5 composite catalyst was used for the hydrogenation of carbon dioxide to produce aviation kerosene. The composite catalyst was activated before the reaction under the following conditions: activation in a hydrogen atmosphere at a flow rate of 30 mL / min, an activation temperature of 350 °C, and an activation time of 2 h.

[0037] The composite catalyst was used for the hydrogenation of carbon dioxide to produce aviation kerosene. The reaction conditions were 300–400 °C, and real-time chromatographic data were collected after the reaction had stabilized for 4 hours. The reaction pressure was 3–5 MPa, and the mass hourly space velocity (WHSV) was 2400–12000 mL·g. cat -1 ·h -1 The production of aviation kerosene by hydrogenating carbon dioxide is carried out in a fixed-bed reactor.

[0038] This invention presents a Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst, its preparation method, and its application. This catalyst significantly improves the catalytic performance of carbon dioxide hydrogenation, and is particularly suitable for the efficient production of aviation kerosene. It possesses at least one of the following beneficial effects: (1) Innovative Preparation Method: This method employs a "MOF topological confinement-stepwise chemical deposition" strategy, innovatively using Ce-MOF as a "sacrificial template." Leveraging the guiding effect of its crystal structure, highly controllable metal oxide precursors are grown in situ on the surface of the molecular sieve support. After calcination, Ce-MOF is transformed into mesoporous CeO2 nanocrystals with high specific surface area and rich in oxygen vacancies (significantly superior to the metal oxide aggregates easily obtained by traditional impregnation methods). Crucially, by integrating multiple metal precursors through MOF crystal engineering strategies, atomically homogeneous metal oxide solid solutions can be formed after calcination. This method overcomes the limitations of physical mixing, not only directionally optimizing the CO2 adsorption activation and H2 dissociation of the catalyst, but also significantly increasing the oxygen vacancy concentration and effectively enhancing: 1) the strong interactions (synergistic effect) between different metals in the multi-metal oxide components; and 2) the interfacial interactions between the active phase of the metal oxide and the molecular sieve support.

[0039] (2) Breakthrough in catalytic performance: CeO2 oxygen vacancies synergistically activate CO2 and H2 with transition metals, improving single-pass conversion rate; multi-metal synergistic enhancement improves the yield of target products. In a fixed-bed reactor ( P =3MPa, T=360℃, GHSV=6000h -1 In this catalyst, a single-pass CO2 conversion rate of 27.8% was achieved, and C8-C 16 The selectivity for straight-chain alkanes reached 64.2% (GC-MS quantitative analysis), and the selectivity for CH4 remained consistently below 10%.

[0040] (3) Superior stability and resistance to deactivation: First, the confinement effect of the molecular sieve framework effectively inhibits the migration and sintering of the metal oxide active phase at high temperatures. Simultaneously, the MOF-derived mesoporous structure significantly optimizes mass transfer efficiency and reduces carbon deposition. Second, the abundant oxygen vacancies (Ov) in CeO2 and the synergistic effect of the multi-metal solid solution endow it with excellent oxygen storage and release capabilities, enabling it to undergo dynamic redox cycles under reaction conditions and continuously repair key active sites. Furthermore, the strong interfacial chemical bonds formed between the metal oxide and the molecular sieve support (such as Si-O-Ce) firmly anchor the active phase, preventing its detachment. Thanks to the combined effect of these mechanisms, the deactivation rate of this catalyst is far lower than that of traditional catalysts. During continuous operation for up to 1000 hours, the catalyst exhibited extremely high durability: TPO testing showed extremely low carbon deposition (<0.1wt%), minimal decrease in specific surface area (SBET) (<3%), and an activity retention rate consistently above 95%. These excellent performance indicators fully demonstrate that it meets the long-term stable operation requirements necessary for industrial applications.

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The components of the embodiments of the present invention described herein and shown can be arranged and designed in various different configurations. Therefore, the following detailed description of the provided embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0042] Example 1 Step 1: Preparation of H-ZSM-5 molecular sieve with a silica-to-alumina ratio of 30: At room temperature, 25.0 g of 40% silica sol was weighed into a beaker, and 2.73 g of NaAlO2, 8.67 g of NaOH, 0.68 g of 25% TPAOH solution, and 180 mL of deionized water were added sequentially. The mixture was magnetically stirred for 30 min until homogeneous, forming a transparent gel. The gel was aged at 30 °C for 2 h, then transferred to a hydrothermal reactor and crystallized at 170 °C for 48 h. After cooling, the gel was filtered and washed with deionized water until neutral. It was dried at 100 °C for 12 h and calcined at 560 °C for 10 h (heating rate 2 °C / min) to remove the template agent. The calcined Na-ZSM-5 was mixed with 1 mol / L NH4NO3 solution at a solid-liquid ratio of 1:20 and stirred at 80 °C for 2 h. This process was repeated once, followed by centrifugation and washing until nitrate ions were removed. The obtained solid product was dried at 100℃ for 10 h and then calcined at 560℃ for 6 h to obtain H-ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 30, which is denoted as H-ZSM-5(30) molecular sieve.

[0043] The second step involves first weighing 0.2 g of H-ZSM-5 (30) molecular sieve and 0.50 g of 1,3,5-BTC and dissolving them in 40 mL of ethanol solution to obtain solution A. Then, weighing 1.04 g of Ce(NO3)3·6H2O and dissolving it in 40 mL of methanol solution to obtain solution B. Solution A is then quickly poured into solution B, 40 mL of deionized water is added, and the mixture is stirred vigorously at room temperature for 20 min. After centrifugation at low speed and washing several times with ethanol, the resulting solid is placed in a vacuum drying oven for 12 h to obtain Ce-MOF grown in situ on the molecular sieve. The solid is then dispersed in 12 mL of methanol to obtain a suspension. 0.297 g of Zn(NO3)2·6H2O and 0.511 g of Ga(NO3)3·xH2O are dissolved in 15 mL of methanol and added dropwise to the suspension under ultrasonic conditions. The mixture is then sonicated for 1 min, allowed to stand for 20 min, centrifuged, and washed several times with ethanol. Finally, the mixture was dried in a freeze dryer for 12 h, and then calcined in air at 300°C with a heating rate of 2 °C / min for 4 h. The obtained sample is designated Ce-Zn1Ga2 / H-ZSM-5(30).

[0044] The third step involves weighing 0.2 g of the prepared catalyst and mixing it with 0.8 g of quartz sand. The mixture is then placed in the isothermal zone of a fixed-bed reactor for evaluation of the carbon dioxide hydrogenation to aviation kerosene catalytic reaction. Activation conditions: Activation is performed in a hydrogen atmosphere at a flow rate of 30 mL / min, an activation temperature of 350℃, and an activation time of 2 h. After activation, the activation gas (hydrogen) is switched to the feed gas and introduced into the fixed-bed reactor at a space velocity of 2400 mL / g. cat -1 h -1The reaction temperature was adjusted to 280℃ and the reaction pressure to 3MPa for catalytic evaluation. The reaction products were directly analyzed online by chromatography. H2, N2, and CO2 were detected by a TCD detector, while hydrocarbons and oxygen-containing compounds were detected by an FID detector. The catalytic evaluation results are shown in Table 1.

[0045] Example 2 Step 1: Preparation of H-ZSM-5 molecular sieve with a silica-to-alumina ratio of 50: At room temperature, 25.0 g of 40% silica sol was weighed into a beaker, and 1.64 g of NaAlO2, 9.20 g of NaOH, 40.68 g of 25% TPAOH solution, and 180 mL of deionized water were added sequentially. The mixture was magnetically stirred for 30 min until homogeneous, forming a transparent gel. The gel was aged at 30 °C for 2 h, then transferred to a hydrothermal reactor and crystallized at 170 °C for 48 h. After cooling, the gel was filtered and washed with deionized water until neutral. It was dried at 100 °C for 12 h and calcined at 560 °C for 10 h (heating rate 2 °C / min) to remove the template agent. The calcined Na-ZSM-5 was mixed with 1 mol / L NH4NO3 solution at a solid-liquid ratio of 1:20 and stirred at 80 °C for 2 h. This process was repeated once, followed by centrifugation and washing until nitrate ions were removed. The obtained solid product was dried at 100℃ for 10 h and then calcined at 560℃ for 6 h to obtain H-ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 50, which is denoted as H-ZSM-5 (50) molecular sieve.

[0046] The second step involves first weighing 0.2 g of H-ZSM-5 (50) molecular sieve and 0.555 g of 1,3,5-BTC and dissolving them in 40 mL of ethanol solution to obtain solution A. Then, weighing 1.04 g of Ce(NO3)3·6H2O and dissolving it in 40 mL of methanol solution to obtain solution B. Solution A is then quickly poured into solution B, 40 mL of deionized water is added, and the mixture is vigorously stirred at room temperature for 20 min. After centrifugation at low speed and washing several times with ethanol, the resulting solid is placed in a vacuum drying oven for 12 h to obtain Ce-MOF grown in situ on the molecular sieve. The solid is then dispersed in 12 mL of methanol to obtain a suspension. 0.297 g of Zn(NO3)2·6H2O and 1.200 g of Cr(NO3)3·9H2O are dissolved in 15 mL of methanol and added dropwise to the suspension under ultrasonic conditions. The mixture is then sonicated for 5 min, allowed to stand for 40 min, centrifuged, and washed several times with ethanol. Finally, the mixture was dried in a freeze dryer for 12 h, and then calcined in air at 400 °C with a heating rate of 2 °C / min for 5 h. The obtained sample was designated Ce-Zn1Cr3 / H-ZSM-5(50).

[0047] The third step involves weighing 0.2 g of the prepared catalyst and mixing it with 0.8 g of quartz sand. The mixture is then placed in the isothermal zone of a fixed-bed reactor for evaluation of the carbon dioxide hydrogenation to aviation kerosene catalytic reaction. Activation conditions: Activation is performed in a hydrogen atmosphere at a flow rate of 30 mL / min, an activation temperature of 350℃, and an activation time of 2 h. After activation, the activation gas (hydrogen) is switched to the feed gas and introduced into the fixed-bed reactor at a space velocity of 4800 mL / g. cat -1 h -1 The reaction temperature was adjusted to 300℃ and the reaction pressure to 4MPa for catalytic evaluation. The reaction products were directly analyzed online by chromatography. H2, N2, and CO2 were detected by a TCD detector, while hydrocarbons and oxygen-containing compounds were detected by an FID detector. The catalytic evaluation results are shown in Table 1.

[0048] Example 3 Step 1: Preparation of H-ZSM-5 molecular sieve with a silica-to-alumina ratio of 100: At room temperature, 25.0 g of 40% silica sol was weighed into a beaker, and 0.82 g of NaAlO2, 9.60 g of NaOH, 40.68 g of 25% TPAOH solution, and 180 mL of deionized water were added sequentially. The mixture was magnetically stirred for 30 min until homogeneous, forming a transparent gel. The gel was aged at 30 °C for 2 h, then transferred to a hydrothermal reactor and crystallized at 170 °C for 48 h. After cooling, the gel was filtered and washed with deionized water until neutral. It was dried at 100 °C for 12 h and calcined at 560 °C for 10 h (heating rate 2 °C / min) to remove the template agent. The calcined Na-ZSM-5 was mixed with 1 mol / L NH4NO3 solution at a solid-liquid ratio of 1:20 and stirred at 80 °C for 2 h. This process was repeated once, followed by centrifugation and washing until nitrate ions were removed. The obtained solid product was dried at 100℃ for 10 h and then calcined at 560℃ for 6 h to obtain H-ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 100, which is denoted as H-ZSM-5(100) molecular sieve.

[0049] The second step involves first dissolving 0.2 g of H-ZSM-5 (100) molecular sieve and 0.605 g of 1,3,5-BTC in 40 mL of ethanol solution to obtain solution A. Then, dissolving 1.04 g of Ce(NO3)3·6H2O in 40 mL of methanol solution to obtain solution B. Solution A is quickly poured into solution B, followed by the addition of 40 mL of deionized water and vigorous stirring at room temperature for 20 min. The mixture is then centrifuged at low speed and washed several times with ethanol. The resulting solid is placed in a vacuum drying oven for 12 h to obtain Ce-MOF grown in situ on the molecular sieve. The solid is then dispersed in 12 mL of methanol to obtain a suspension. 0.297 g of Zn(NO3)2·6H2O and 0.251 g of Mn(NO3)2·4H2O are dissolved in 15 mL of methanol and added dropwise to the suspension under ultrasonic conditions. The mixture is then sonicated for 15 min, allowed to stand for 60 min, centrifuged, and washed several times with ethanol. Finally, the mixture was dried in a freeze dryer for 12 h, and then calcined in air at 450 °C with a heating rate of 2 °C / min for 6 h. The obtained sample is designated Ce-Zn1Mn1 / H-ZSM-5(100).

[0050] The third step involves weighing 0.2 g of the prepared catalyst and mixing it with 0.8 g of quartz sand. The mixture is then placed in the isothermal zone of a fixed-bed reactor for evaluation of the catalytic reaction of carbon dioxide hydrogenation to aviation kerosene. Activation conditions: Activation is performed in a hydrogen atmosphere at a flow rate of 30 mL / min, an activation temperature of 350℃, and an activation time of 2 h. After activation, the activation gas (hydrogen) is switched to the feed gas and introduced into the fixed-bed reactor at a space velocity of 6000 mL / g. cat -1 h -1 The reaction temperature was adjusted to 320℃ and the reaction pressure to 5MPa for catalytic evaluation. The reaction products were directly analyzed online by chromatography. H2, N2, and CO2 were detected by a TCD detector, while hydrocarbons and oxygen-containing compounds were detected by an FID detector. The catalytic evaluation results are shown in Table 1.

[0051] Example 4 Step 1: Preparation of H-ZSM-5 molecular sieve with a silica-to-alumina ratio of 200: At room temperature, 25.0 g of 40% silica sol was weighed into a beaker, and 0.41 g of NaAlO2, 9.80 g of NaOH, 40.68 g of 25% TPAOH solution, and 180 mL of deionized water were added sequentially. The mixture was magnetically stirred for 30 min until homogeneous, forming a transparent gel. The gel was aged at 30 °C for 2 h, then transferred to a hydrothermal reactor and crystallized at 170 °C for 48 h. After cooling, the gel was filtered and washed with deionized water until neutral. It was dried at 100 °C for 12 h and calcined at 560 °C for 10 h (heating rate 2 °C / min) to remove the template agent. The calcined Na-ZSM-5 was mixed with 1 mol / L NH4NO3 solution at a solid-liquid ratio of 1:20 and stirred at 80 °C for 2 h. The exchange process was repeated once, and the mixture was centrifuged and washed until nitrate was removed. The obtained solid product was dried at 100℃ for 10 h and then calcined at 560℃ for 6 h to obtain H-ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 200, which is denoted as H-ZSM-5(200) molecular sieve.

[0052] The second step involves first weighing 0.2 g of H-ZSM-5 (200) molecular sieve and 0.50 g of 1,3,5-BTC and dissolving them in 40 mL of ethanol solution to obtain solution A. Then, weighing 1.04 g of Ce(NO3)3·6H2O and dissolving it in 40 mL of methanol solution to obtain solution B. Solution A is quickly poured into solution B, 40 mL of deionized water is added, and the mixture is vigorously stirred at room temperature for 20 min. The mixture is then centrifuged at low speed and washed several times with ethanol. The resulting solid is placed in a vacuum drying oven for 12 h to obtain Ce-MOF grown in situ on the molecular sieve. The solid is then dispersed in 12 mL of methanol to obtain a suspension. 0.595 g of Zn(NO3)2·6H2O and 0.491 g of In(NO3)3·5H2O are dissolved in 15 mL of methanol and added dropwise to the suspension under ultrasonic conditions. The mixture is then sonicated for 30 min, allowed to stand for 90 min, centrifuged, and washed several times with ethanol. Finally, the mixture was dried in a freeze dryer for 12 h, and then calcined in air at 500 °C with a heating rate of 2 °C / min for 7 h. The obtained sample is designated Ce-Zn2In1 / H-ZSM-5(200).

[0053] The third step involves weighing 0.2 g of the prepared catalyst and mixing it with 0.8 g of quartz sand. The mixture is then placed in the isothermal zone of a fixed-bed reactor for evaluation of the catalytic reaction of carbon dioxide hydrogenation to aviation kerosene. Activation conditions: Activation is performed in a hydrogen atmosphere at a flow rate of 30 mL / min, an activation temperature of 350℃, and an activation time of 2 h. After activation, the activation gas (hydrogen) is switched to the feed gas and introduced into the fixed-bed reactor at a space velocity of 7200 mL / g. cat -1 h -1The reaction temperature was adjusted to 340℃ and the reaction pressure to 3MPa for catalytic evaluation. The reaction products were directly analyzed online by chromatography. H2, N2, and CO2 were detected by a TCD detector, while hydrocarbons and oxygen-containing compounds were detected by an FID detector. The catalytic evaluation results are shown in Table 1.

[0054] Example 5 Step 1: Preparation of H-ZSM-5 molecular sieve with a silica-to-alumina ratio of 100: At room temperature, 25.0 g of 40% silica sol was weighed into a beaker, and 0.82 g of NaAlO2, 9.60 g of NaOH, 40.68 g of 25% TPAOH solution, and 180 mL of deionized water were added sequentially. The mixture was magnetically stirred for 30 min until homogeneous, forming a transparent gel. The gel was aged at 30 °C for 2 h, then transferred to a hydrothermal reactor and crystallized at 170 °C for 48 h. After cooling, the gel was filtered and washed with deionized water until neutral. It was dried at 100 °C for 12 h and calcined at 560 °C for 10 h (heating rate 2 °C / min) to remove the template agent. The calcined Na-ZSM-5 was mixed with 1 mol / L NH4NO3 solution at a solid-liquid ratio of 1:20 and stirred at 80 °C for 2 h. This process was repeated once, followed by centrifugation and washing until nitrate ions were removed. The obtained solid product was dried at 100℃ for 10 h and then calcined at 560℃ for 6 h to obtain a molecular sieve with a silicon-to-aluminum ratio of 100, denoted as H-ZSM-5(100).

[0055] The second step involves first weighing 0.2 g of H-ZSM-5 (100) molecular sieve and 0.50 g of 1,3,5-BTC and dissolving them in 40 mL of ethanol solution to obtain solution A. Then, weighing 1.04 g of Ce(NO3)3·6H2O and dissolving it in 40 mL of methanol solution to obtain solution B. Solution A is quickly poured into solution B, 40 mL of deionized water is added, and the mixture is vigorously stirred at room temperature for 20 min. The mixture is then centrifuged at low speed and washed several times with ethanol. The resulting solid is placed in a vacuum drying oven for 12 h to obtain Ce-MOF grown in situ on the molecular sieve. The solid is then dispersed in 12 mL of methanol to obtain a suspension. 0.892 g of Zn(NO3)2·6H2O and 0.256 g of Ga(NO3)3·xH2O are dissolved in 15 mL of methanol and added dropwise to the suspension under ultrasonic conditions. The mixture is then sonicated for 60 min, allowed to stand for 30 min, centrifuged, and washed several times with ethanol. Finally, the mixture was dried in a freeze dryer for 12 h, and then calcined in air at 600 °C with a heating rate of 2 °C / min for 8 h. The obtained sample is designated Ce-Zn3Ga1 / H-ZSM-5(100).

[0056] The third step involves evaluating the catalytic reaction of carbon dioxide hydrogenation to aviation kerosene in a fixed-bed reactor under constant temperature. Activation conditions: activation in a hydrogen atmosphere at a flow rate of 30 mL / min, an activation temperature of 350℃, and an activation time of 2 h. After activation, the activation gas (hydrogen) is switched to the feed gas and introduced into the fixed-bed reactor at a space velocity of 12000 mL / g. cat -1 h -1 The reaction temperature was adjusted to 360℃ and the reaction pressure to 4MPa for catalytic evaluation. The reaction products were directly analyzed online by chromatography. H2, N2, and CO2 were detected by a TCD detector, while hydrocarbons and oxygen-containing products were detected by an FID detector. The catalytic evaluation results are shown in Table 1.

[0057] Comparative Example 1 Molecular sieves and metal oxides are physically ground and mixed before being loaded. Step 1: Preparation of H-ZSM-5 molecular sieve with a silica-to-alumina ratio of 30: At room temperature, 25.0 g of 40% silica sol was weighed into a beaker, and 2.73 g of NaAlO2, 8.67 g of NaOH, 40.68 g of 25% TPAOH solution, and 180 mL of deionized water were added sequentially. The mixture was magnetically stirred for 30 min until homogeneous, forming a transparent gel. The gel was aged at 30 °C for 2 h, then transferred to a hydrothermal reactor and crystallized at 170 °C for 48 h. After cooling, the gel was filtered and washed with deionized water until neutral. It was dried at 100 °C for 12 h and calcined at 560 °C for 10 h (heating rate 2 °C / min) to remove the template agent. The calcined Na-ZSM-5 was mixed with 1 mol / L NH4NO3 solution at a solid-liquid ratio of 1:20 and stirred at 80 °C for 2 h. This process was repeated once, followed by centrifugation and washing until nitrate ions were removed. The obtained solid product was dried at 100℃ for 10 h and then calcined at 560℃ for 6 h to obtain H-ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 30, which is denoted as H-ZSM-5(30) molecular sieve.

[0058] The second step involves the synthesis of metal oxides. First, 0.50 g of 1,3,5-BTC was weighed and dissolved in 40 mL of ethanol solution to obtain solution A. 1.04 g of Ce(NO3)3·6H2O was weighed and dissolved in 40 mL of methanol solution to obtain solution B. Solution A was quickly poured into solution B, 40 mL of deionized water was added, and the mixture was vigorously stirred at room temperature for 20 min. The mixture was then centrifuged at low speed and washed several times with ethanol. The resulting solid was placed in a vacuum drying oven for 12 h to obtain dried Ce-MOF. The solid was dispersed in 12 mL of methanol to obtain a suspension. 0.297 g of Zn(NO3)2·6H2O and 0.511 g of Ga(NO3)3·xH2O were dissolved in 15 mL of methanol and added dropwise to the suspension under ultrasonic conditions. The mixture was then sonicated for 15 min, allowed to stand for 30 min, centrifuged, and washed several times with ethanol. Finally, the mixture was dried in a freeze dryer for 12 h, and then calcined in air at 450°C with a heating rate of 2 °C / min for 5 h. The obtained sample was designated Ce-Zn1Ga2.

[0059] The third step involves weighing 0.2g of H-ZSM-5 (30) molecular sieve and 0.2g of Ce-Zn1Ga2 powder into an agate mortar, manually grinding them for 5 minutes, then placing them in a small centrifuge tube and shaking until fully mixed. The mixture is then loaded into a fixed-bed reactor in powder form and kept at a constant temperature for evaluation of the catalytic reaction of carbon dioxide hydrogenation to aviation kerosene. Activation conditions: at a space velocity of 12000 mL / g... cat -1 h -1 Under a hydrogen atmosphere, the temperature was increased from room temperature to 350℃ at a rate of 10℃ / min for 2 hours. After activation, the argon activation gas was switched to the feed gas and introduced into the fixed-bed reactor. The reaction temperature was adjusted to 300℃ and the reaction pressure to 3MPa for catalytic evaluation. The reaction products were directly analyzed online by chromatography. H2, N2, and CO2 were detected by a TCD detector, while hydrocarbons and oxygen-containing compounds were detected by an FID detector. The catalytic evaluation results are shown in Table 1.

[0060] Comparative Example 2 Metal oxides are layered on top and molecular sieves are at the bottom. Step 1: Preparation of H-ZSM-5 molecular sieve with a silica-to-alumina ratio of 50: At room temperature, 25.0 g of 40% silica sol was weighed into a beaker, and 1.64 g of NaAlO2, 9.20 g of NaOH, 40.68 g of 25% TPAOH solution, and 180 mL of deionized water were added sequentially. The mixture was magnetically stirred for 30 min until homogeneous, forming a transparent gel. The gel was aged at 30 °C for 2 h, then transferred to a hydrothermal reactor and crystallized at 170 °C for 48 h. After cooling, the gel was filtered and washed with deionized water until neutral. It was dried at 100 °C for 12 h and calcined at 560 °C for 10 h (heating rate 2 °C / min) to remove the template agent. The calcined Na-ZSM-5 was mixed with 1 mol / L NH4NO3 solution at a solid-liquid ratio of 1:20 and stirred at 80 °C for 2 h. This process was repeated once, followed by centrifugation and washing until nitrate ions were removed. The obtained solid product was dried at 100℃ for 10 h and then calcined at 560℃ for 6 h to obtain H-ZSM-5 molecular sieve with a silicon-to-aluminum ratio of 50, which is denoted as H-ZSM-5 (50) molecular sieve.

[0061] The second step involves first dissolving 0.555 g of 1,3,5-BTC in 40 mL of ethanol to obtain solution A, and then dissolving 1.04 g of Ce(NO3)3·6H2O in 40 mL of methanol to obtain solution B. Solution A is quickly poured into solution B, followed by the addition of 40 mL of deionized water and vigorous stirring at room temperature for 20 min. The mixture is then centrifuged at low speed and washed several times with ethanol. The resulting solid is placed in a vacuum drying oven for 12 h to obtain dried Ce-MOF. The solid is then dispersed in 12 mL of methanol to obtain a suspension. 0.297 g of Zn(NO3)2·6H2O and 1.200 g of Cr(NO3)3·9H2O are dissolved in 15 mL of methanol and added dropwise to the suspension under ultrasonic conditions. The mixture is then sonicated for 5 min, allowed to stand for 20 min, centrifuged, and washed several times with ethanol. Finally, the mixture was dried in a freeze dryer for 12 h, and then calcined in air at 450 °C with a heating rate of 2 °C / min for 5 h. The obtained sample was designated Ce-Zn1Cr3.

[0062] The third step involved weighing 0.2g of H-ZSM-5 (50) molecular sieve and 0.2g of Ce-Zn1Cr3 powder, placing the metal oxide in the upper layer of the reaction tube and the molecular sieve in the lower layer. Both catalysts were loaded into a fixed-bed reactor in powder form for constant-temperature evaluation of the catalytic reaction of carbon dioxide hydrogenation to aviation kerosene. Activation conditions: Activation was performed in a hydrogen atmosphere at a flow rate of 30mL / min, an activation temperature of 350℃, and an activation time of 2h. After activation, the activation gas (hydrogen) was switched to the feed gas and introduced into the fixed-bed reactor at a space velocity of 9000mL / g. cat -1 h-1 The reaction temperature was adjusted to 320℃ and the reaction pressure to 4MPa for catalytic evaluation. The reaction products were directly analyzed online by chromatography. H2, N2, and CO2 were detected by a TCD detector, while hydrocarbons and oxygen-containing products were detected by an FID detector. The catalytic evaluation results are shown in Table 1.

[0063] Table 1. Comparison of catalytic evaluation results of the composite catalysts prepared in Examples 1-5 and Comparative Examples 1-2

[0064] Table 1 compares the catalytic evaluation results of the composite catalysts prepared in Examples 1-5 and Comparative Examples 1-2. Based on the data analysis in the table, the first five samples showed superior catalytic performance, particularly in CO2 conversion and C8-C8 conversion. 16 In terms of selectivity, the carbon dioxide conversion rate is 17.6%–27.8%; methane selectivity is 3.8%–8.9%; carbon monoxide selectivity is 42.1%–55.2%; C8–C 16 The hydrocarbon selectivity ranged from 64.2% to 72.3%. Compared with physical mixing and dual-bed mixing methods, the catalysts in Examples 1-5 exhibited superior overall performance, indicating that the tighter bonding between the molecular sieve and the metal oxide effectively generates long-chain hydrocarbons, thus improving the overall catalyst performance. CO2 conversion generally increased with increasing temperature, but decreased at the highest temperature (360°C), possibly due to over-activation of the catalyst itself.

[0065] In summary, this invention discloses a Ce-MOF-derived multimetal oxide / ZSM-5-based composite catalyst, its preparation method, and its applications. The composite catalyst consists of Ce-BTC-derived multi-component metal oxides (ternary or higher) and H-ZSM-5 molecular sieves, and is prepared through the following steps: First, H-ZSM-5 molecular sieves are synthesized using a hydrothermal method. Subsequently, Ce-MOF (metal-organic framework) is grown in situ on the surface of the molecular sieve. Utilizing the unique high specific surface area, well-developed pore structure, and abundant unsaturated sites of Ce-MOF materials (which can effectively anchor metal sites), efficient loading of various active metals is achieved. Finally, after drying and calcination, a structurally stable Ce-MOF-derived metal oxide / ZSM-5 composite catalyst is obtained. The catalyst's functions are manifested in the following aspects: 1) Ce-MOF-derived polymetallic oxides (Ce-ZnGa, Ce-ZnCr, Ce-ZnMn) possess abundant oxygen vacancies and active sites, which can efficiently activate CO2 molecules and promote their hydrogenation process with H2, generating the key methanol intermediate; 2) The coupling strategy between metal oxides and molecular sieves can precisely regulate the carbon chain growth of methanol intermediates, enabling rapid and effective conversion of methanol intermediates; 3) The regular pore structure and suitable acidic sites of ZSM-5 molecular sieves, based on the cage-controlled shape-selective catalysis principle of H-ZSM-5 molecular sieves, selectively generate C8~C6 molecules. 16 Aviation kerosene components. The catalyst of this invention has excellent catalytic performance, with a single-pass CO2 conversion rate exceeding 25%, and aviation kerosene components (C8~C9). 16 This catalyst exhibits a selectivity of up to 70.5% in hydrocarbon products while effectively suppressing the formation of methane byproducts (selectivity <10%). It demonstrates excellent reaction stability (>500h), a simple preparation process, low raw material costs, and ease of scale-up production, providing an efficient technical solution for CO2 resource utilization and green aviation fuel production.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst, characterized in that, include: 1) A silicon source, aluminum source, template agent, alkaline solution and deionized water are mixed and stirred to form a uniform gel. After aging, hydrothermal crystallization, washing with water until neutral, first drying, and first high-temperature calcination, sodium molecular sieve is obtained. Sodium molecular sieve is mixed and stirred with NH4NO3 solution; after repeated exchange once, centrifugation and washing until nitrate is free, second drying, and second high-temperature calcination, proton-type H-ZSM-5 molecular sieve is obtained. 2) Proton-type H-ZSM-5 molecular sieve, cerium nitrate solution and 1,3,5-BTC solution were stirred and mixed. After the first static in-situ growth, the Ce-MOF was obtained by centrifugation, alcohol washing and first freeze-drying. The Ce-MOF grown in situ on the molecular sieve was dispersed in methanol solution, and methanol solution containing two metal nitrates was added. After sonication and a second static period, the Ce-MOF was centrifuged, freeze-dried a second time, calcined, ground, pressed into tablets and granulated to obtain Ce-MOF-derived multimetal oxide / ZSM-5-based composite catalyst.

2. The preparation method of the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst according to claim 1, characterized in that, In step 1), the molar ratio of the silicon source, aluminum source, template agent, alkaline solution and deionized water is 1:(0.016~0.0025):0.25:0.05:30; The silicon source is SiO2; the aluminum source is sodium aluminate; the template agent is tetrapropylammonium hydroxide; and the alkaline solution is NaOH. The solid-liquid ratio of the sodium molecular sieve to the NH4NO3 solution is 1:

20.

3. The method for preparing the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst according to claim 1, characterized in that, In step 1), the aging time is 2 hours; The conditions for hydrothermal crystallization are: hydrothermal crystallization at 170℃ for 48 hours; The conditions for the first drying were: drying at 100℃ for 12 hours; The conditions for the first high-temperature calcination were: heating to 560℃ at a heating rate of 2℃ / min and calcining at high temperature for 10 hours; The mixing conditions are: mixing at 80°C for 2 hours; The conditions for the second drying were: drying at 100℃ for 10 hours; The conditions for the second high-temperature calcination are: calcination at 560℃ for 6 hours.

4. The method for preparing the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst according to claim 1, characterized in that, In step 2), the molar ratio of the cerium nitrate solution to the 1,3,5-BTC solution is 1:1 to 1:

2.

5. The method for preparing the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst according to claim 1, characterized in that, In step 2), the first settling time is 2 hours; The centrifugation conditions were: centrifugation at 3000 rpm for 5 minutes; The duration of the ultrasound is 1-60 minutes; The second settling time is 20-90 minutes; The temperature for both the first and second freeze-drying processes was -50°C, and the time was 12 hours. The calcination temperature is 300~600℃, and the calcination time is 4~8h; The granulation process involves particles with a diameter of 60-80 mesh.

6. A Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst, characterized in that, The Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst was prepared by any one of claims 1 to 5, wherein the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst comprises Ce-MOF-derived polymetallic oxide and molecular sieve H-ZSM-5. The Ce-MOF-derived polymetallic oxide is used for the efficient conversion of carbon dioxide into methanol intermediate; The molecular sieve H-ZSM-5 utilizes cage-controlled shape-selective catalysis to catalyze the C-C bond coupling reaction of methanol intermediates to synthesize aviation kerosene components.

7. The Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst according to claim 6, characterized in that, The Ce-MOF-derived polymetallic oxide uses Ce-MOF as a precursor and is formed by stepwise loading of one or two transition metals from Zn, Ga, Cr, Mn and In.

8. The Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst according to claim 6, characterized in that, In the molecular sieve H-ZSM-5, the molar ratio of Si to Al is 30~200.

9. The application of the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst prepared by the method according to any one of claims 1 to 5 in the catalytic hydrogenation of CO2 to produce aviation kerosene, characterized in that, The Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst was mixed with quartz sand and placed in the isothermal zone of a fixed-bed reactor for evaluation of the catalytic reaction of CO2 catalytic hydrogenation to produce aviation kerosene.

10. The application of the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst according to claim 9 in the catalytic hydrogenation of CO2 to produce aviation kerosene, characterized in that, Before using the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst for CO2 catalytic hydrogenation to produce aviation kerosene, it is first activated under the following conditions: activation at 350°C for 2 hours in hydrogen. The mass ratio of the Ce-MOF-derived polymetallic oxide / ZSM-5-based composite catalyst to quartz sand is 1:

4. The reaction conditions for the CO2 catalytic hydrogenation to prepare aviation kerosene include: a temperature of 280~360℃, a reaction pressure of 3~5MPa, and a mass hourly space velocity of 2400~12000 mL g. cat -1 h -1 H2 / CO2 = 3:1.

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