A catalyst for preparing liquid fuel by CO2 hydrogenation and a preparation method and application thereof

Abstract

The application relates to the technical field of liquid fuel preparation, and discloses a catalyst for preparing liquid fuel through CO2 hydrogenation as well as a preparation method and application of the catalyst. The catalyst preparation method comprises the following steps: (1) synthesizing Na-MOR molecular sieves through a template-free hydrothermal method, and sequentially performing ammonium exchange, pyridine adsorption, sodium exchange, metal salt exchange and diethylamine solution exchange to obtain 8Na-12Me-MOR molecular sieves; and (2) mixing the 8Na-12Me-MOR molecular sieves and metal oxides to obtain the catalyst. According to the application, Na ions selectively occupy 8-member ring acid sites of the MOR molecular sieves, metal ions partially exchange 12-member ring acid sites, the 12-member ring acid strength and the pore environment are effectively controlled, the product is concentrated in the C5-C 11 range, the selectivity of the liquid fuel can reach 65-80%, the selectivity of methane is lower than 12%, and the stability of the catalyst is excellent.

Description

Technical Field

[0001] This invention relates to the field of liquid fuel preparation technology, and in particular to a catalyst for the preparation of liquid fuel by CO2 hydrogenation, its preparation method, and its application. Background Technology

[0002] Liquid fuels (primarily gasoline fractions, i.e., hydrocarbons with 5 to 11 carbon atoms) are the primary energy source in the transportation sector, and their production is highly dependent on petroleum refining. With increasingly scarce petroleum resources and increasingly stringent environmental requirements, developing non-petroleum-based liquid fuel synthesis technologies is of great significance. Directly synthesizing gasoline fraction hydrocarbons from greenhouse gas carbon dioxide (CO2) and renewable hydrogen (such as green hydrogen) through catalytic conversion can achieve the recycling of carbon resources.

[0003] Currently, research on the direct preparation of hydrocarbon products by CO2 hydrogenation mainly focuses on low-carbon olefins (C2O4). = -C4 = This includes areas such as low-carbon alkanes (C2-C4) and aromatics. It also targets gasoline fractions (C5-C4). 11 There are few reports on the direct selective synthesis of carbon chains (C5-C6), and the main challenge lies in how to precisely control the carbon chain length within the C5-C6 range. 11 Within this range, the formation of methane and C2-C4 byproducts is simultaneously suppressed. There are two main existing technical routes: one is the improved Fischer-Tropsch synthesis (FTS) route, using iron-based or cobalt-based catalysts, where the carbon number distribution of the product follows the Anderson-Schulz-Flory (ASF) distribution, C5-C... 11 The theoretical upper limit of fraction selectivity is about 50%, and methane selectivity is usually as high as 15-30%, resulting in high energy consumption for product separation. For example, patent CN117753452B discloses a method for the co-production of liquid hydrocarbons from CO2 hydrogenation to ethanol and its iron-based catalyst. The second route is the methanol-mediated (OXZEO) route, which uses a bifunctional catalyst composed of metal oxides and molecular sieves, controlling the carbon number of the product through the pores and acidic sites of the molecular sieve. For example, SAPO-34 (eight-membered ring) can be used to obtain low-carbon olefins with high selectivity; ZSM-5 (ten-membered ring) can obtain gasoline fractions rich in aromatics, but with high aromatic content, low alkane selectivity, and easy carbon deposition and deactivation. For high-selectivity synthesis of C5-C... 11 Reports on hydrocarbons (i.e., alkylated gasoline or renewable gasoline) are limited, mainly due to the difficulty in addressing C5-C... 11 The formation of hydrocarbons requires both a suitable pore structure for chain growth reactions and suitable acidic sites to avoid intermediates (C2). = -C4 = Hydrogenation produces C2-C4. Summary of the Invention

[0004] This invention aims to overcome the aforementioned problems in the prior art by providing a catalyst for the hydrogenation of CO2 to liquid fuels, its preparation method, and its applications. Based on the unique twelve-membered ring main channel (6.5 × 7.0 Å) and tunable acidic site distribution of MOR molecular sieves, it achieves constraint on the carbon chain length by selectively shielding the acidic sites of the eight-membered ring side pockets and simultaneously partially exchanging the twelve-membered ring acidic sites with metal ions, thus concentrating the product in the C5-C range. 11 It has a wide range of applications and exhibits excellent catalyst stability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a catalyst for the hydrogenation of CO2 to produce liquid fuels, comprising the following steps: (1) Na-MOR molecular sieve raw powder was synthesized by a template-free hydrothermal method; (2) Add Na-MOR molecular sieve raw powder to ammonium nitrate aqueous solution for ion exchange, and then dry and calcinate to obtain H-MOR molecular sieve; (3) After adsorbing pyridine onto H-MOR molecular sieve, 8H-12Py-MOR molecular sieve is obtained; (4) Add 8H-12Py-MOR molecular sieve to sodium nitrate aqueous solution for ion exchange, and then dry and calcinate to obtain 8Na-12H-MOR molecular sieve; (5) 8Na-12H-MOR molecular sieve was subjected to ion exchange with metal salt and diethylamine solution, and then dried and calcined to obtain 8Na-12Me-MOR molecular sieve. (6) The catalyst is obtained by mechanically mixing 8Na-12Me-MOR molecular sieve with metal oxide.

[0006] In this invention, the catalyst is a bifunctional composite catalyst obtained by mechanically mixing a metal oxide with a specially ion-exchange modified MOR molecular sieve (8Na-12Me-MOR). The metal oxide is responsible for activating carbon dioxide and hydrogen to generate methanol or related oxygen-containing intermediates; the modified MOR molecular sieve, utilizing its unique twelve-membered ring main channel and precisely controlled acidic sites, selectively converts these intermediates into C5-C... 11 Liquid fuel. This invention effectively suppresses the formation of small molecule olefins (such as ethylene) by pre-occupying acidic sites within the 8-membered ring channel with Na ions. Simultaneously, by partially introducing metal ions (Me), the acid strength and density within the 12-membered ring channel are adjusted, promoting moderate oligomerization, isomerization, and hydrogenation saturation of olefin intermediates within the channel, thereby obtaining highly selective C5-C... 11 The isoparaffin significantly inhibited the rate of carbon deposition on the catalyst, thereby greatly improving the reaction stability of the catalyst.

[0007] As a preferred option, the steps of synthesizing Na-MOR molecular sieve raw powder by hydrothermal method without template agent in step (1) are as follows: mix silica sol, sodium aluminate, sodium hydroxide and deionized water, stir evenly and transfer to hydrothermal reactor, hydrothermally crystallize and then cool rapidly to room temperature in water bath, separate the product, wash and dry to obtain Na-MOR molecular sieve raw powder.

[0008] Preferably, the molar ratio of silica sol, sodium aluminate, sodium hydroxide, and deionized water, based on SiO2, Al2O3, Na2O, and H2O, is 20~30:1:0.25~0.30:30~60; the hydrothermal crystallization temperature is 150~200℃, and the time is 60~80h.

[0009] Preferably, in step (2), the concentration of the ammonium nitrate aqueous solution is 0.5~2 mol / L, the ion exchange temperature is 70~90℃, and the time is 3~5h; the calcination temperature is 400~600℃, and the time is 3~5h.

[0010] As a preferred option, the pyridine adsorption conditions in step (3) are: temperature of 300~400℃ and time of 2~5h.

[0011] Preferably, in step (4), the concentration of the sodium nitrate aqueous solution is 0.2~1 mol / L, the temperature of the ion exchange is 70~90℃, and the time is 3~5h; the calcination temperature is 400~600℃, and the time is 3~5h.

[0012] Preferably, the metal salt mentioned in step (5) is copper nitrate or zinc nitrate, the concentration of the metal salt is 0.05~2 mol / L, the concentration of diethylamine is 0.05~2 mol / L, the ion exchange temperature is 50~80℃, and the time is 2~8 h.

[0013] Preferably, the 8Na-12Me-MOR molecular sieve obtained in step (5) has the characteristics of medium-strong acid, and the molar amount of medium-strong acid sites is 0.4-1.5 mol / kg, more preferably 0.4-1.0 mol / kg, and even more preferably 0.6-1.0 mol / kg.

[0014] Acid strength is defined by the NH3-TPD peak and includes three types of acidity: weak acid, moderately strong acid, and strong acid.

[0015] This NH3-TPD method categorizes inorganic solids into three acid strengths based on the desorption peak position of NH3. The desorption peak position is determined under standard test conditions: a sample mass w to carrier gas flow rate f ratio (w / f) = 100 g·h / L, and a heating rate of 10℃ / min. The TCD records the thermal conductivity signal of desorbed NH3, and a desorption curve is plotted. The inorganic solid is then classified into three acid strengths based on the peak position of the curve: weak acid (NH3 desorption temperature below 245℃), moderately strong acid (NH3 desorption temperature between 245-500℃), and strong acid (NH3 desorption temperature above 500℃).

[0016] Preferably, the metal oxide mentioned in step (6) is InZr. x O (1+1.5x) GaZr x O (1+1.5x) ZnCr x O (1+1.5x) ZnAl x O (1+1.5x) ZnGa x O (1+1.5x) and ZnZr x O (1+1.5x) At least one of the following, wherein x takes the value of 0.1 to 10; the specific surface area of ​​the metal oxide is 5 to 150 m². 2 / g, more preferably 100~150 m 2 / g.

[0017] Preferably, in step (6), the mass ratio of the metal oxide to the 8Na-12Me-MOR molecular sieve is 0.1~20:1, more preferably 0.3~5:1.

[0018] Secondly, the present invention discloses a catalyst for the preparation of liquid fuels by hydrogenation of CO2 using the above-described preparation method.

[0019] Thirdly, this invention discloses an application of the above-mentioned catalyst for the preparation of liquid fuel by hydrogenation of CO2, wherein the method is as follows: a mixture of hydrogen and carbon dioxide is brought into contact with the catalyst to react and prepare liquid fuel.

[0020] This invention uses carbon dioxide and hydrogen as reactants to directly convert liquid fuels in one step. The selectivity of liquid fuels can reach 65-80%, while the selectivity of by-products methane is <12% and the selectivity of C2-C4 hydrocarbons is <23%, which has good application prospects.

[0021] Preferably, the molar ratio of carbon dioxide to hydrogen is 1:0.2 to 4.5, more preferably 1:0.3 to 3.5; the pressure of the mixed gas is 0.5 to 10 MPa, more preferably 1 to 5 MPa.

[0022] Preferably, the reaction temperature is 300~500℃, more preferably 320~450℃; the space velocity of the mixed gas is 300~12000 mL / g / h, more preferably 1000~8000 mL / g / h, and even more preferably 1500~8000 mL / g / h.

[0023] Therefore, the present invention has the following beneficial effects: (1) This invention applies MOR molecular sieves modified with a specific ion exchange strategy to the direct production of liquid fuels from CO2 hydrogenation. By selectively shielding the 8-membered ring sites with Na ions and partially adjusting the acidity of the 12-membered ring with metal ions, the product is successfully shifted from ethylene-based olefins to C5-C-based olefins. 11 Primarily liquid fuels; (2) In this invention, the strong acid sites of the modified MOR molecular sieve (8Na-12Me-MOR) are effectively weakened, the catalyst carbon deposition rate is significantly reduced, and the stability is excellent. It exhibits excellent stability under high temperature and high pressure reaction conditions. (3) The catalyst prepared by the method of the present invention can directly convert CO2 and H2 into liquid fuel with a selectivity of 65-80%, methane selectivity <12%, C2-C4 hydrocarbon selectivity <23%, low separation energy consumption, and high technical and economic efficiency. Attached Figure Description

[0024] Figure 1 The NH3-TPD diagrams are for the molecular sieves prepared in Example 1 and Comparative Example 2.

[0025] Figure 2 The figures show the stability evaluation curves of the catalytic reaction in Example 2 and Comparative Example 2. Detailed Implementation

[0026] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0027] In this invention, unless otherwise specified, all equipment and raw materials are available from the market or commonly used in the industry. The methods in the following embodiments are conventional methods in the field unless otherwise specified.

[0028] 1. Metal oxides (1) The metal oxides CuAl2O4, ZnO and FeO were all commercially available; the 10% FeO+InZr2O4 catalyst was obtained by mixing ZnO and InZr2O4, and FeO accounted for 10% of the total mass of FeO+InZr2O4.

[0029] (2) The preparation method of other metal oxides includes the following steps: using two of zinc nitrate, chromium nitrate, aluminum nitrate, zirconium nitrate, indium nitrate and gallium nitrate as precursors, mixing the precursors with ammonium carbonate in water at room temperature, wherein ammonium carbonate is used as a precipitant, and the molar ratio of ammonium ions to metal ions is 1:1 (or, ammonium carbonate can be in excess); aging the resulting mixture, taking it out after aging, washing, filtering and drying in sequence; calcining the resulting solid in an air atmosphere to obtain metal oxides.

[0030] The metal oxide in this invention was prepared by the precipitation method described above. The specific parameters used in the preparation process are shown in Table 1, and all other conditions were the same. The metal oxide was InZr. x O (1+1.5x) ,GaZr x O (1+1.5x) ZnCr x O (1+1.5x) ZnAl x O (1+1.5x) ZnGa x O (1+1.5x) and ZnZr x O (1+1.5x) One or more of the following, where x ranges from 0.1 to 10. The specific surface area of ​​the metal oxide is 5 to 150 m². 2 / g.

[0031] Table 1: Preparation parameters of metal oxides

[0032] 2. Molecular sieves (1) The preparation method of conventional H-MOR molecular sieve includes the following steps: Weigh silica sol, sodium aluminate, sodium hydroxide, and deionized water according to the molar ratio of SiO2:Al2O3:Na2O:H2O=25:1.0:0.28:50. After mixing and aging at room temperature for 2 h, transfer to a stainless steel hydrothermal reactor and heat to 180℃ at a heating rate of 2℃ / min for 72 h of rotary crystallization. After crystallization, cool to room temperature in a water bath and repeatedly centrifuge and wash until the pH of the supernatant is 7 at the end of washing. Dry the precipitate at 120℃ for 12 h to obtain Na-MOR molecular sieve. Add the above Na-MOR molecular sieve raw powder to a 1.0 mol / L ammonium nitrate aqueous solution and ion exchange at 80℃ for 4 h. Repeat twice, then dry and calcine at 500℃ for 4 h to obtain conventional H-MOR molecular sieve.

[0033] (2) The preparation method of 8Na-12Me-MOR (taking Me=Mg as an example, i.e. 8Na-12Mg-MOR) molecular sieve includes the following steps: adsorb pyridine on the above H-MOR molecular sieve at 350℃ for 4 h to obtain 8H-12Py-MOR molecular sieve. 8H-12Py-MOR molecular sieve was added to a 0.5 mol / L sodium nitrate aqueous solution and subjected to ion exchange at 80℃ for 4 h, followed by drying and calcination at 550℃ for 4 h to obtain 8Na-12H-MOR molecular sieve. 8Na-12H-MOR molecular sieve was subjected to ion exchange with a mixed solution of 0.1 mol / L magnesium nitrate and 0.1 mol / L diethylamine at 60℃ for 6 h, followed by drying and calcination at 550℃ for 4 h to obtain 8Na-12Mg-MOR molecular sieve. By adjusting the type and concentration of the metal salt (e.g., magnesium nitrate, manganese nitrate), 8Na-12Me-MOR molecular sieves with different metal ion exchanges (Me = Mg, Mn, etc.) can be obtained. The preparation parameters of the molecular sieves used in the embodiments of this invention are shown in Table 2, and all other conditions are the same.

[0034] Table 2: Preparation parameters of molecular sieves

[0035] 3. Catalyst The desired proportions of metal oxides and molecular sieves are added to a container and mechanically mixed to obtain a catalyst. Separation, crushing, and mixing are achieved by utilizing one or more of the forces such as extrusion, impact, shearing, and friction generated by the high-speed movement of the material and / or container. The conversion of mechanical energy, thermal energy, and chemical energy is achieved by adjusting the temperature and carrier gas atmosphere, further regulating the interactions between different components.

[0036] In a specific embodiment of the present invention, during the mechanical mixing process, the mixing temperature can be set to 20~100°C, and the mixing can be carried out in an atmosphere or directly in air. The atmosphere is selected from any of the following gases: a) nitrogen and / or an inert gas; b) a mixture of hydrogen and nitrogen and / or an inert gas, wherein the volume of hydrogen in the mixture is 5~50%; c) a mixture of CO and nitrogen and / or an inert gas, wherein the volume of CO in the mixture is 5-20%; d) a mixture of O2 and nitrogen and / or an inert gas, wherein the volume of O2 in the mixture is 5~20%. The inert gas is one or more of helium, argon, and neon.

[0037] In a specific embodiment of the present invention, mechanical mixing may be performed using one or more of the following methods: mechanical stirring, ball milling, shaking table mixing, and mechanical grinding, as detailed below: a) Mechanical stirring: In a stirring tank, metal oxides and molecular sieves are mixed using a stirring rod. By controlling the stirring time (5~120 min) and speed (30~300 rpm), the degree of mixing and relative distance between the metal oxides and molecular sieves can be adjusted. b) Ball milling: The abrasive and metal oxides and molecular sieves are rolled at high speed in the grinding tank, which generates strong impact and crushing on the catalyst, thereby dispersing and mixing the metal oxides and molecular sieves; the particle size of the catalyst can be adjusted by controlling the mass ratio of abrasive (material can be stainless steel, agate, quartz, size range: 5~15 mm) to catalyst to 20~100:1. c) Shaking: The metal oxide and molecular sieve are premixed and loaded into a container; the metal oxide and molecular sieve are mixed by controlling the reciprocating or circular oscillation of the shaker; uniform mixing and adjustment of their relative distance are achieved by adjusting the oscillation speed (range: 1~70 rpm) and time (range: 5~120 min); d) Mechanical grinding: The metal oxide and molecular sieve are premixed and loaded into a container; under a certain pressure (range: 5~20 kg), the mixed catalyst is subjected to relative motion by a grinding tool (speed range: 30~300 rpm) to adjust the particle size and relative distance of the catalyst and achieve uniform mixing.

[0038] 4. Catalytic reaction The catalytic reaction is carried out in a fixed-bed reactor or a moving-bed reactor. The reactor is equipped with a gas mass flow meter and an online product analysis chromatograph (the reactor tail gas is directly connected to the quantitative valve of the chromatograph for periodic real-time sampling and analysis). The air in the reactor is replaced with an inert gas (one or more of helium, argon, and neon). A mixture of carbon dioxide and hydrogen is used as the raw material to carry out the catalytic reaction in contact with the catalyst. The molar ratio of carbon dioxide to hydrogen is 1:0.2~4.5, the reaction temperature is 300~500℃, the pressure of the mixed gas is 0.5~10 MPa, and the space velocity of the mixed gas is 300~12000 mL / g / h.

[0039] Examples 1-10 and Comparative Examples 1-9 (1) Metal oxides are prepared by precipitation method, and the specific preparation parameters are shown in Table 1; or, commercially available metal oxides are used. (2) MOR molecular sieves were prepared using a specific ion exchange strategy. The specific preparation parameters are shown in Table 2. (3) The required proportion of metal oxide and molecular sieve are added to a container for mechanical mixing to obtain the catalyst. The specific catalyst preparation and its parameter characteristics are shown in Table 3 and Table 4. (4) Catalytic reaction was carried out using carbon dioxide and hydrogen as raw materials in contact with the catalyst. 2 g of catalyst was placed in a fixed-bed reactor, and the air in the reactor was replaced with argon. The reactor was then heated to 300 °C in an H2 atmosphere. A mixture of carbon dioxide and hydrogen (H2 / CO2 molar ratio = 0.2~4.5) was switched, with a mixed gas pressure of 0.5~10 MPa. The temperature was raised to the reaction temperature of 300~500 °C, and the space velocity of the mixed gas was adjusted to 300~12000 mL / g / h. Specific parameters of the catalytic reaction are shown in Table 5. The products were analyzed by online chromatography, and the results are shown in Table 6.

[0040] Table 3: Preparation parameters of catalysts in Examples 1-10

[0041] Table 4: Preparation parameters of catalysts in Comparative Examples 1-9

[0042] Table 5: Catalytic reaction parameters used in Examples 1-10 and Comparative Examples 1-9

[0043] Table 6: Catalyst application effect data in Examples 1-10 and Comparative Examples 1-9 (30 h)

[0044] As shown in Table 6, Examples 1-10 demonstrate that by changing the temperature, pressure, space velocity, and the molar ratio of H2 / CO2 in the catalytic reaction, the final catalytic effect will vary, but the overall catalytic activity, selectivity, and stability are high. After 30 h of reaction, the CO2 conversion rate can still reach 30-40%, and after 30 h of reaction, the C5-C... 11 The selectivity of liquid fuels can reach 60-80%, the selectivity of C2-C4 hydrocarbons is less than 23%, and the selectivity of methane is less than 12%.

[0045] like Figure 1 The NH3-TPD diagrams of the molecular sieves prepared in Example 1 (part 3) and Comparative Example 2 (part 2) are shown, indicating that the number of strong acid sites decreases after metal ion exchange in the 12-membered ring channels.

[0046] Comparative Example 1 used an H-MOR molecular sieve as its catalyst (both 8-membered and 12-membered rings contain acidic sites), and the products were mainly C2-C4 low-carbon olefins, with C5-C... 11The selectivity for liquid fuels is very low. In Comparative Example 2, the catalyst used an 8Na-12H-MOR molecular sieve (only the 12-membered ring contains acidic sites), which showed high selectivity for C2-C4 hydrocarbons but low selectivity for liquid fuels, and the catalyst deactivated quickly. For example... Figure 2 The figure shown is a catalytic stability evaluation diagram of the catalysts in Comparative Example 2 and Example 2. It can be clearly seen that the catalyst in Comparative Example 2 has significant deactivation of catalytic activity after 30 h of reaction.

[0047] Comparative Example 3 and Example 3 were compared, and Comparative Example 4 and Example 5 were compared. The molecular sieves used in Comparative Example 3 and Comparative Example 4 were 8H-12Me-MOR molecular sieves with excess Mg or Mn ion exchange. The reaction results showed that excess metal ions led to an increase in the selectivity of C2-C4 hydrocarbons and methane, while the selectivity of liquid fuels decreased.

[0048] Comparing Comparative Examples 5-6 with Example 1, Comparative Example 5 used a catalyst containing only metal oxides and no molecular sieves, resulting in a very low reaction conversion rate and products mainly consisting of dimethyl ether, methane, and other byproducts, with very low selectivity for liquid fuels. Comparative Example 6 used a catalyst containing only molecular sieves and no metal oxides; since molecular sieves lack the ability to activate CO2, the catalytic reaction had almost no activity. Comparative Examples 5-6 demonstrate that the catalytic reaction effect is poor when only metal oxides or molecular sieves are used, completely lacking the excellent reaction performance described in this invention.

[0049] Comparing Comparative Example 7 and Example 4, the catalyst used in Comparative Example 7 was a Cu-based oxide, which resulted in a very low reaction conversion rate, and the products were mainly byproducts such as methane (C5-C). 11 The selectivity for hydrocarbons is very low. Comparing Comparative Example 8 with Example 5, the catalyst used in Comparative Example 8 is a single-component ZnO catalyst with large grain size and low specific surface area (<1 m²). 2 / g), and the surface lacks partially reduced O defect structures, resulting in a very low reaction conversion rate and severe hydrogenation. The product exhibits high selectivity for C2-C4 hydrocarbons and methane. Comparing Comparative Example 9 with Example 1, the catalyst used in Comparative Example 9 also contained 10% FeO in its oxide component, and the reaction products were mainly C2-C4 hydrocarbons and methane, with C5-C... 11 The selectivity of the liquid fuel was low, significantly lower than in Example 1. This is because FeO in the catalyst was reduced during the reaction to form iron carbide, thus transforming the reaction process into the traditional Fischer-Tropsch synthesis route. The product distribution followed the ASF distribution, no longer meeting the requirements of this invention. The technical effects of this invention could not be achieved. The reaction results of Comparative Examples 7-9 show that the oxide component in the catalyst used is crucial for the preparation of highly selective low-carbon olefins.

[0050] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made using the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing a catalyst for the hydrogenation of CO2 to liquid fuel, characterized in that, The steps include the following: (1) Na-MOR molecular sieve raw powder was synthesized by a template-free hydrothermal method; (2) Add Na-MOR molecular sieve raw powder to ammonium nitrate aqueous solution for ion exchange, and then dry and calcinate to obtain H-MOR molecular sieve; (3) After adsorbing pyridine onto H-MOR molecular sieve, 8H-12Py-MOR molecular sieve is obtained; (4) Add 8H-12Py-MOR molecular sieve to sodium nitrate aqueous solution for ion exchange, and then dry and calcinate to obtain 8Na-12H-MOR molecular sieve; (5) 8Na-12H-MOR molecular sieve is subjected to ion exchange with metal salt and diethylamine solution, and then dried and calcined to obtain 8Na-12Me-MOR molecular sieve; the metal salt is magnesium nitrate or manganese nitrate. (6) The catalyst is obtained by mechanically mixing 8Na-12Me-MOR molecular sieve with a metal oxide; the metal oxide is InZr. x O (1+1.5x) GaZr x O (1+1.5x) ZnCr x O (1+1.5x) ZnAl x O (1+1.5x) ZnGa x O (1+1.5x) and ZnZr x O (1+1.5x) At least one of the following, where x takes the value from 0.1 to 10.

2. The method for preparing the catalyst for CO2 hydrogenation to liquid fuel according to claim 1, characterized in that, The steps for synthesizing Na-MOR molecular sieve raw powder by hydrothermal method without template agent in step (1) are as follows: mix silica sol, sodium aluminate, sodium hydroxide and deionized water, stir evenly and transfer to hydrothermal reactor, hydrothermally crystallize and then cool rapidly to room temperature in water bath, separate the product, wash and dry to obtain Na-MOR molecular sieve raw powder.

3. The method for preparing the catalyst for CO2 hydrogenation to liquid fuel according to claim 2, characterized in that, The molar ratio of silica sol, sodium aluminate, sodium hydroxide, and deionized water, calculated as SiO2, Al2O3, Na2O, and H2O, is 20~30:1:0.25~0.30:30~60; the hydrothermal crystallization temperature is 150~200℃, and the time is 60~80h.

4. The method for preparing the catalyst for CO2 hydrogenation to liquid fuel according to claim 1, characterized in that, In step (5), the concentration of the metal salt is 0.05~2 mol / L, the concentration of diethylamine is 0.05~2 mol / L, the ion exchange temperature is 50~80℃, and the time is 2~8 h.

5. The method for preparing the catalyst for CO2 hydrogenation to liquid fuel according to claim 1, characterized in that, In step (6), the specific surface area of ​​the metal oxide is 5~150 m². 2 / g.

6. The method for preparing the catalyst for CO2 hydrogenation to liquid fuel according to claim 1 or 5, characterized in that, In step (6), the mass ratio of the metal oxide to the 8Na-12Me-MOR molecular sieve is 0.1~20:

1.

7. A catalyst for the hydrogenation of CO2 to produce liquid fuels, characterized in that, It is prepared by any one of the preparation methods described in claims 1 to 6.

8. The application of a catalyst for the hydrogenation of CO2 to produce liquid fuels as described in claim 7, characterized in that, The method involves contacting a mixture of hydrogen and carbon dioxide with a catalyst to react and prepare liquid fuel.

9. The application of the catalyst for CO2 hydrogenation to liquid fuel production according to claim 7, characterized in that, The molar ratio of carbon dioxide to hydrogen is 1:0.2~4.5; the pressure of the mixed gas is 0.5~10 MPa.

10. The application of the catalyst for CO2 hydrogenation to liquid fuel production according to claim 7, characterized in that, The reaction temperature is 300~500℃, and the space velocity of the mixed gas is 300~12000 mL / g / h.

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