Preparation method and application of metal oxide-molecular sieve composite catalyst

Abstract

The invention relates to preparation and application of a metal oxide-molecular sieve composite catalyst, and belongs to the technical field of industrial catalysis. The catalytic reaction takes carbon dioxide and hydrogen as reaction raw materials, and the catalyst is formed by compounding a metal oxide and a molecular sieve. Wherein the metal oxide is a solid solution metal oxide or a spinel metal oxide composed of three or two metal elements of M1, M2 and M3, M1 is one of Zn, Ga and In, M2 is one of Ce, Sm, La and Fe, and M3 is one of Zr, Ga, Cr, Al and Ti; the framework of the molecular sieve is a silicon-aluminum-oxygen or silicon-phosphorus-aluminum-oxygen tetrahedron; the metal oxide is prepared by adopting a gas diffusion method. The metal oxide disclosed by the invention is prepared by adopting a gas diffusion method, and has a very high specific surface area (80-300 m < 2 > g <-1 >). The composite catalyst shows excellent performance in a reaction for preparing low-carbon olefins (ethylene, propylene and butylene) through carbon dioxide hydrogenation, the carbon dioxide conversion rate can reach 35% or above, the carbon monoxide selectivity is smaller than 40%, the selectivity of the low-carbon olefins in hydrocarbons can reach 82.1%, the yield of the low-carbon olefins reaches 20.3%, and the composite catalyst has high catalytic stability. Compared with a traditional catalyst, carbon dioxide and hydrogen can be efficiently adsorbed and activated, so that the conversion rate of carbon dioxide is increased, the preparation method is simple, the catalytic performance is excellent, and the catalyst has good industrial application prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial catalysis, and specifically relates to the preparation and catalytic application of a metal oxide - molecular sieve composite catalyst with a high specific surface area. Background Art

[0002] The rapid development of the global industry highly depends on fossil energy. However, the traditional utilization mode of fossil energy has exacerbated the excessive emission of carbon dioxide, which has in turn led to climate problems such as the greenhouse effect and ocean acidification. Currently, the global is facing the severe problem of the greenhouse effect caused by carbon dioxide emissions. By the end of 2022, the concentration of carbon dioxide in the atmosphere reached 418.56 ppm, setting a new record in history, which is 51% higher than the pre - industrial level. Controlling carbon dioxide emissions, using it as a carbon - based raw material, and developing clean conversion and utilization models to mitigate climate change have become a global consensus.

[0003] Lower olefins such as ethylene, propylene, and butene are important organic chemical raw materials, which are widely used in the production of various chemicals. Currently, the production of lower olefins is mainly obtained through the thermal cracking of naphtha and gas oil or the steam cracking of light components in petroleum. The raw materials for producing lower olefins by this traditional method highly depend on non - renewable fossil raw materials, and there are serious carbon dioxide emission problems in the production process. In contrast, using captured carbon dioxide or carbon dioxide in industrial tail gas as a carbon source and converting it into lower olefins through a catalytic hydrogenation process is an effective way for carbon dioxide resource utilization. Currently, there are mainly two technical routes for preparing lower olefins from carbon dioxide. The first is the improved Fischer - Tropsch synthesis route with carbon monoxide as an intermediate. However, due to the Anderson - Schulz - Flory (ASF) limitation, there is a problem of a wide distribution of hydrocarbon products, the selectivity of lower olefins is usually less than 58%, and the selectivity of methane is high. In addition, this route also has the problem of too high carbon monoxide selectivity. The second is the methanol - mediated route using a metal oxide / molecular sieve composite catalyst, in which the coupled composite catalyst is usually obtained by physically mixing metal oxide and molecular sieve components according to a certain mass ratio. The composite catalyst formed by coupling metal oxide and molecular sieve can separate the two processes of carbon dioxide activation and carbon - carbon bond formation, breaking the limitation of lower olefin selectivity. Compared with the Fischer - Tropsch route, the selectivity of lower olefins in this route can reach more than 80%, so the yield of lower olefins is relatively high, becoming the mainstream technical route for future development.

[0004] However, at present, the metal oxide / molecular sieve composite catalysts for the hydrogenation of carbon dioxide have the problems of relatively low specific surface area of the metal oxide and fewer catalytic active interfaces exposed on the catalyst surface, which leads to poor performance in the hydrogenation of CO2. As reported in the literature Chemical Engineering Journal 500 (2024) 157398, the InZnZrO x / SAPO-34 composite catalyst, in which the specific surface area of InZnZrO x prepared by the co-precipitation method is only 38.26 m 2 g -1 . Under the conditions of 380 °C, 2 MPa, volume ratio of carbon dioxide: hydrogen: argon being 24:72:4, and GHSV = 6000 mL / (g cat h), the selectivity for light olefins remains 80.1%, the selectivity for carbon monoxide is 44.6%, while the conversion rate of carbon dioxide is only 17.9%; for the ZnZrO x / SAPO-34 composite catalyst reported in the literature Chemical Engineering Journal 503 (2025) 158350, in which the specific surface area of ZnZrO x prepared by the co-precipitation method is only 20 m 2 g -1 . Under the conditions of 370 °C, 4 MPa, volume ratio of carbon dioxide: hydrogen: argon being 24:72:4, and GHSV = 3600 mL / (g cat h), the selectivity for light olefins is 83.8%, the selectivity for carbon monoxide is 36.3%, and the conversion rate of carbon dioxide is only 17.3%; for the ZnZrO x / H-RUB-13 composite catalyst reported in the literature Ind. Eng. Chem. Res. 2022,61, 10409−10418, in which the specific surface area of ZnZrO x prepared by the sol-gel method is 47 m 2 g -1 . Under the conditions of 350 °C, 3 MPa, volume ratio of carbon dioxide: hydrogen being 1:3, and GHSV = 4000 mL / (g cat h), the selectivity for light olefins is only 76.8%, and the conversion rate of carbon dioxide is only 15.5%. It can be seen that most of the current composite catalysts are coupled on the premise of metal oxides with low specific surface area. It is difficult for metal oxides to expose more active sites, the activation ability of carbon dioxide and hydrogen is limited, the reverse water-gas shift is serious, and it is difficult to obtain high catalytic performance. SUMMARY OF THE INVENTION The problem to be solved by the present invention is the problem of low CO2 hydrogenation performance caused by the low specific surface area of metal oxides in the existing process of hydrogenating carbon dioxide to produce light olefins. A preparation method of metal oxides with high specific surface area is provided, and such metal oxides with high specific surface area are coupled with molecular sieves to form a composite catalyst and applied to the reaction of hydrogenating carbon dioxide to produce light olefins. This catalyst exhibits higher carbon dioxide conversion rate, light olefin selectivity and catalytic stability than traditional catalysts.

[0006] A preparation method of a metal oxide - molecular sieve composite catalyst comprises the following steps: The metal oxide - molecular sieve composite catalyst comprises a metal oxide and a molecular sieve; The metal oxide is a solid - solution metal oxide or a spinel - type metal oxide composed of three or two of M1, M2, and M3 metal elements, where M1 is one of Zn, Ga, and In, M2 is one of Ce, Sm, La, and Fe, and M3 is one of Zr, Ga, Cr, Al, and Ti; The framework composition of the molecular sieve is silicon - aluminum - oxygen or silicon - phosphorus - aluminum - oxygen tetrahedra; The metal oxide is prepared by a gas diffusion method.

[0007] The metal oxide with high specific surface area and the molecular sieve are physically mixed to form a composite catalyst, and the reaction is carried out under certain temperature, pressure, space velocity and volume ratio of carbon dioxide to hydrogen gas, and catalytic performance with high carbon dioxide conversion rate, low carbon monoxide selectivity, high light olefin selectivity and high light olefin yield is obtained.

[0008] Preferably, the metal oxide is prepared by a gas diffusion method. Specifically, it is a metal oxide prepared by introducing a volatile precipitant into a metal precursor solution in a gas - phase transmission manner. The metal precursor solution is a mixed solution of two metal salts or a mixed solution of three metal salts. In the mixed solution of two metal salts, the molar ratio of M1 to M3 is any value among 0, 0.1, 0.2, 0.3, 0.4, 0.5, 1 or the range value between any two of them; in the mixed solution of three metal salts, the molar ratio of M1 to (M2 + M3) is any value among 0.1, 0.2, 0.3, 0.4, 0.5, 1 or the range value between any two of them; in the mixed solution of three metal salts, the molar ratio of M2 to M3 is any value among 0.1, 0.2, 0.3, 0.4, 0.5, 1 or the range value between any two of them; When it is a mixed solution of two metal salts, the metals are M1 and M3, that is, M1 is one of Zn, Ga, and In, and M3 is one of Zr, Ga, Cr, Al, and Ti.

[0009] Metal salt: It refers to an ionic compound containing metal cations and acid radical anions.

[0010] Solution: It refers to a homogeneous mixture in which a solute (such as a metal salt) is uniformly dispersed in a solvent (such as water).

[0011] The metal precursor solution can be, but is not limited to, a mixed solution formed by one or more of metal nitrates such as zinc nitrate, zirconium nitrate, gallium nitrate, indium nitrate, cerium nitrate, samarium nitrate, chromium nitrate, aluminum nitrate, etc. The metal precursor solution can also be a mixed solution formed by one or more of metal sulfates and metal carbonates.

[0012] The volatile precipitant includes one or a mixture of two of ammonia water, ethylenediamine, diethylamine, triethylamine, dipropylamine, isopropylamine, 1,2 - propanediamine, n - butylamine, isobutylamine, sec - butylamine, tert - butylamine, di - n - butylamine, 1,4 - butanediamine.

[0013] Preferably, the crystallization time required for the gas diffusion method is 0 - 200 hours; the required calcination atmosphere is one of argon, air, 10% hydrogen / argon; the required calcination temperature is 400 - 900 °C; the required calcination time is 0.1 - 12 h.

[0014] Preferably, the metal oxides include ZnZrO x 、GaZrO x 、InZrO x 、ZnCeZrO x 、GaCeZrO x 、InCeZrO x 、ZnGaZrO x 、ZnSmZrO x 、solid solution metal oxides or spinel - type metal oxides such as ZnGa2O4, ZnCr2O4, ZnAl2O4; the molecular sieves include SAPO - 34, SAPO - 18 aluminosilicate phosphates or silicoaluminosilicate SSZ - 13.

[0015] Preferably, the mixing method of the metal oxide and the molecular sieve is one of double - bed layer mixing, particle mixing, ball - milling mixing, and powder mixing.

[0016] A method for preparing olefins by hydrogenating carbon dioxide, the method uses a metal oxide - molecular sieve composite catalyst, and the metal oxide is the metal oxide - molecular sieve composite catalyst prepared by the above method.

[0017] Preferably, a mixed gas containing carbon dioxide and hydrogen is used as the raw material gas, and the reaction occurs under the condition of reaction pressure, and the catalyst used in the reaction is the aforementioned metal oxide - molecular sieve composite catalyst.

[0018] The present invention provides a method for preparing metal oxides with high specific surface area, comprising the following steps: (1) Dissolve metal salts in water to form a mixed solution A; form a mixed solution B with a volatile precipitant; place the beaker containing the mixed solution A and the beaker containing the mixed solution B in a closed container; (2) At room temperature, the volatile precipitant will spontaneously diffuse from beaker B into beaker A, changing the pH of the solution in beaker A and gradually generating a precipitate containing metal elements. The precipitate is recovered by centrifugation and calcined to obtain a metal oxide catalyst.

[0019] In step (1), the molar ratio of M1 to M3 in the two metal salt solutions is any value among 0, 0.1, 0.2, 0.3, 0.4, 0.5, 1 or a range value between any two of them; The molar ratio of M1 to (M2 + M3) in the three metal salt solutions is any value among 0.1, 0.2, 0.3, 0.4, 0.5, 1 or a range value between any two of them; The molar ratio of M2 to M3 in the three metal salt solutions is any value among 0.1, 0.2, 0.3, 0.4, 0.5, 1 or a range value between any two of them; In step (2), the crystallization time is 0 to 200 hours; The calcination atmosphere is one of argon, air, and 10% hydrogen / argon; The calcination temperature is 400 to 900 °C; The calcination time is 0.1 to 12 h.

[0020] The metal oxide structure is one of spinel or solid solution, and the synthesis method is the gas diffusion method.

[0021] The metal oxide includes but is not limited to ZnZrO x , GaZrO x , InZrO x , ZnCeZrO x , GaCeZrO x , InCeZrO x , ZnGaZrO x , ZnSmZrO x , a solid solution metal oxide or a spinel-type metal oxide such as ZnGa2O4, ZnCr2O4, ZnAl2O4.

[0022] The molecular sieve component includes but is not limited to silicoaluminophosphate molecular sieves such as SAPO-34, SAPO-18, or silicoaluminosilicate molecular sieve SSZ-13, etc.

[0023] The molecular sieve framework composition is silicon-aluminum-oxygen or silicon-phosphorus-aluminum-oxygen tetrahedrons, and the synthesis methods include hydrothermal synthesis, dry gel synthesis, post-treatment synthesis, solvent-free synthesis, and non-aqueous solvent synthesis.

[0024] The structure of the metal oxide is one of spinel or solid solution, and the synthesis method is gas diffusion method.

[0025] The preparation method of the composite catalyst is physical mixing, which is one of double-bed layer mixing, particle mixing, ball milling mixing, shaker mixing, and powder mixing.

[0026] The reaction conditions include: Reaction temperature: 320°C to 440°C, preferably 360°C to 400°C.

[0027] Reaction pressure: 1 MPa to 6 MPa, preferably 1 MPa to 4 MPa.

[0028] The volume ratio of hydrogen to carbon dioxide is 3 / 1 to 6 / 1. Reaction space velocity: 1500 to 20000 mL / (g cat h), preferably 3000 to 9000 mL / (g cat h).

[0029] The mass ratio of the metal oxide to the molecular sieve in the mixture: 3 / 1 to 1 / 3, preferably 2 / 1 to 1 / 2.

[0030] Beneficial effects: The present invention synthesizes a metal oxide with a high specific surface area (usually 80 - 300 m 2 g -1 ) and its preparation method by gas diffusion method, which solves the problems of low specific surface area and low CO2 activation efficiency of the metal oxide prepared by traditional synthesis methods. By coupling with the molecular sieve, a significant increase in the yield of light olefins is achieved. When catalyzing the hydrogenation of carbon dioxide to light olefins, the conversion rate of carbon dioxide can reach 38.8%, the selectivity of carbon monoxide can reach 36.4%, the selectivity of light olefins in hydrocarbons can reach 82.1%, and the yield of light olefins is as high as 20.3%. Description of the drawings

[0031] Figure 1 It is the catalytic data graph of Example 51; Figure 2 They are XRD graphs obtained from the metal oxides prepared according to Examples 21, 22, 16, 18, 15, 14, 17, 29, 28, 26, 1, 25, and 24 respectively. Detailed implementation manners

[0032] The present application will be described in detail below in conjunction with embodiments, but the present application is not limited to the described embodiments.

[0033] Unless otherwise specified, the raw materials in the embodiments of the present application are all purchased through commercial channels. Except for the high specific surface area metal oxides synthesized by the gas diffusion method, the molecular sieves and metal oxides involved in the present application are all prepared according to the existing synthesis methods.

[0034] Example 1: Zn 13 Zr 87 O x (Volatile precipitant: ammonia water) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate and dissolve them in 300 g of deionized water, and ultrasonically obtain a clear solution. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a sealed container, stand still for crystallization for 100 h, filter, wash three times with deionized water, dry overnight at 110 °C, calcine at 300 °C for 1 h in an air atmosphere, calcine at 500 °C for 3 h, and cool to room temperature to obtain the catalyst ZnZrO x . 150 mg of ZnZrO x is ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), tableted and granulated, with a particle size of 20-40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C, and in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate to be 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0035] Example 2: ZnZrO x (Volatile precipitant: ethylenediamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate and dissolve them in 300 g of deionized water, and ultrasonically obtain a clear solution. Weigh 36.42 g of ethylenediamine and disperse it in 300 g of deionized water. Transfer the two solutions to a sealed container, stand still for crystallization for 100 h, filter, wash three times with deionized water, dry overnight at 110 °C, calcine at 300 °C for 1 h in an air atmosphere, calcine at 500 °C for 3 h, and cool to room temperature to obtain the catalyst ZnZrO x . 150 mg of ZnZrO xIt was ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), pelletized, with a particle size of 20-40 mesh. 150 mg was weighed and loaded into a quartz tube, pretreated at normal pressure, 400 °C, in an argon atmosphere for 2 hours. Subsequently, a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, the flow rate was controlled at 15 mL / min, and the reaction was carried out at 3 MPa and 380 °C for 16 hours.

[0036] Example 3: ZnZrO x (Volatile precipitant: diethylamine) 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate were dissolved in 300 g of deionized water and ultrasonicated to obtain a clear solution. 44.10 g of diethylamine was dispersed in 300 g of deionized water. The two solutions were transferred to a closed container, allowed to crystallize for 100 h, filtered, washed three times with deionized water, dried overnight at 110 °C, calcined at 300 °C in an air atmosphere for 1 h, calcined at 500 °C for 3 h, and cooled to room temperature to obtain the catalyst ZnZrO x 。150 mg of ZnZrO x It was ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), pelletized, with a particle size of 20-40 mesh. 150 mg was weighed and loaded into a quartz tube, pretreated at normal pressure, 400 °C, in an argon atmosphere for 2 hours. Subsequently, a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, the flow rate was controlled at 15 mL / min, and the reaction was carried out at 3 MPa and 380 °C for 16 hours.

[0037] Example 4: ZnZrO x (Volatile precipitant: triethylamine) 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate were dissolved in 300 g of deionized water and ultrasonicated to obtain a clear solution. 61.02 g of triethylamine was dispersed in 300 g of deionized water. The two solutions were transferred to a closed container, allowed to crystallize for 100 h, filtered, washed three times with deionized water, dried overnight at 110 °C, calcined at 300 °C in an air atmosphere for 1 h, calcined at 500 °C for 3 h, and cooled to room temperature to obtain the catalyst ZnZrO x 。150 mg of ZnZrO xMix 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, tablet and granulate, with a particle size of 20 - 40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat it for 2 hours under normal pressure, at 400 °C, in an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0038] Example 5: ZnZrO x (Volatile precipitant: dipropylamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate, dissolve them in 300 g of deionized water and sonicate to obtain a clear solution. Weigh 61.33 g of dipropylamine and disperse it in 300 g of deionized water. Transfer the two solutions to a closed container, let it stand for crystallization for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZnZrO x . 150 mg of ZnZrO x Mix 150 mg of ZnZrO with 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, tablet and granulate, with a particle size of 20 - 40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat it for 2 hours under normal pressure, at 400 °C, in an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0039] Example 6: ZnZrO x (Volatile precipitant: isopropylamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate, dissolve them in 300 g of deionized water and sonicate to obtain a clear solution. Weigh 35.82 g of isopropylamine and disperse it in 300 g of deionized water. Transfer the two solutions to a closed container, let it stand for crystallization for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZnZrO x . 150 mg of ZnZrO xMix 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, tablet and granulate to a particle size of 20-40 mesh. Weigh 150 mg and place it in a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C under an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0040] Example 7: ZnZrO x (Volatile precipitant: 1,2-propanediamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate, dissolve them in 300 g of deionized water and sonicate to obtain a clear solution. Weigh 44.92 g of 1,2-propanediamine and disperse it in 300 g of deionized water. Transfer the two solutions to a sealed container, allow it to crystallize statically for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZnZrO x 。150 mg of ZnZrO x Mix 150 mg of ZnZrO with 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, tablet and granulate to a particle size of 20-40 mesh. Weigh 150 mg and place it in a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C under an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0041] Example 8: ZnZrO x (Volatile precipitant: n-butylamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate, dissolve them in 300 g of deionized water and sonicate to obtain a clear solution. Weigh 44.33 g of n-butylamine and disperse it in 300 g of deionized water. Transfer the two solutions to a sealed container, allow it to crystallize statically for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZnZrO x 。150 mg of ZnZrO xMix 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, tablet and granulate it to a particle size of 20-40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C under an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0042] Example 9: ZnZrO x (Volatile precipitant: isobutylamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate and dissolve them in 300 g of deionized water, and ultrasonically obtain a clear solution. Weigh 44.33 g of isobutylamine and disperse it in 300 g of deionized water. Transfer the two solutions to a closed container, stand and crystallize for 100 h, filter, wash three times with deionized water, dry overnight at 110 °C, calcine in air atmosphere at 300 °C for 1 h, calcine at 500 °C for 3 h, and cool to room temperature to obtain the catalyst ZnZrO x 。150 mg of ZnZrO x Mix 150 mg of ZnZrO with 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, tablet and granulate it to a particle size of 20-40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C under an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0043] Example 10: ZnZrO x (Volatile precipitant: sec-butylamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate and dissolve them in 300 g of deionized water, and ultrasonically obtain a clear solution. Weigh 44.33 g of sec-butylamine and disperse it in 300 g of deionized water. Transfer the two solutions to a closed container, stand and crystallize for 100 h, filter, wash three times with deionized water, dry overnight at 110 °C, calcine in air atmosphere at 300 °C for 1 h, calcine at 500 °C for 3 h, and cool to room temperature to obtain the catalyst ZnZrO x 。150 mg of ZnZrO xMix 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, pelletize by tabletting, with a particle size of 20 - 40 mesh. Weigh 150 mg and load it into a quartz tube. Pretreat it for 2 hours under normal pressure, at 400 °C, in an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0044] Example 11: ZnZrO x (Volatile precipitant: tert-butylamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate, dissolve them in 300 g of deionized water and ultrasonically obtain a clear solution. Weigh 44.33 g of tert-butylamine and disperse it in 300 g of deionized water. Transfer the two solutions to a closed container, allow it to crystallize statically for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZnZrO x 。150 mg of ZnZrO x Mix 150 mg of ZnZrO with 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, pelletize by tabletting, with a particle size of 20 - 40 mesh. Weigh 150 mg and load it into a quartz tube. Pretreat it for 2 hours under normal pressure, at 400 °C, in an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0045] Example 12: ZnZrO x (Volatile precipitant: di-n-butylamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate, dissolve them in 300 g of deionized water and ultrasonically obtain a clear solution. Weigh 77.94 g of di-n-butylamine and disperse it in 300 g of deionized water. Transfer the two solutions to a closed container, allow it to crystallize statically for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZnZrO x 。150 mg of ZnZrO xMix 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, pelletize by tableting, with a particle size of 20-40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C under an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0046] Example 13: ZnZrO x (Volatile precipitant: 1,4-butanediamine) Weigh 1.1602 g of zinc nitrate and 11.2053 g of zirconium nitrate, dissolve them in 300 g of deionized water and ultrasonically obtain a clear solution. Weigh 53.97 g of 1,4-butanediamine and disperse it in 300 g of deionized water. Transfer the two solutions to a closed container, let it stand for crystallization for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZnZrO x 。150 mg of ZnZrO x Mix 150 mg of ZnZrO with 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, pelletize by tableting, with a particle size of 20-40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C under an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0047] Example 14: GaZrO x (Volatile precipitant: ammonia water) Weigh 0.9974 g of gallium nitrate and 12.1068 g of zirconium nitrate, dissolve them in 300 g of deionized water and ultrasonically obtain a clear solution. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a closed container, let it stand for crystallization for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst GaZrO x 。150 mg of GaZrO xIt was ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), tableted and granulated to a particle size of 20-40 mesh. 150 mg was weighed and placed into a quartz tube, pre-treated under normal pressure, at 400 °C, in an argon atmosphere for 2 hours. Subsequently, a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, the flow rate was controlled at 15 mL / min, and the reaction was carried out at 3 MPa and 380 °C for 16 hours.

[0048] Example 15: InZrO x (Volatile precipitating agent: ammonia water) 1.3838 g of indium nitrate and 11.2053 g of zirconium nitrate were weighed and dissolved in 300 g of deionized water, and ultrasonic treatment was carried out to obtain a clear solution. 79.4 g of ammonia water was weighed and diluted to 300 g of deionized water. The two solutions were transferred to a sealed container, allowed to stand and crystallize for 100 h, filtered, washed three times with deionized water, dried overnight at 110 °C, calcined in an air atmosphere at 300 °C for 1 h, calcined at 500 °C for 3 h, and cooled to room temperature to obtain the catalyst InZrO x 150 mg of InZrO x It was ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), tableted and granulated to a particle size of 20-40 mesh. 150 mg was weighed and placed into a quartz tube, pre-treated under normal pressure, at 400 °C, in an argon atmosphere for 2 hours. Subsequently, a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, the flow rate was controlled at 15 mL / min, and the reaction was carried out at 3 MPa and 380 °C for 16 hours.

[0049] Example 16: ZnCeZrO x (Volatile precipitating agent: ammonia water) 1.1602 g of zinc nitrate, 1.1333 g of cerium nitrate, and 10.0847 g of zirconium nitrate were weighed and dissolved in 300 g of deionized water, and ultrasonic treatment was carried out to obtain a clear solution. 79.4 g of ammonia water was weighed and diluted to 300 g of deionized water. The two solutions were transferred to a sealed container, allowed to stand and crystallize for 100 h, filtered, washed three times with deionized water, dried overnight at 110 °C, calcined in an air atmosphere at 300 °C for 1 h, calcined at 500 °C for 3 h, and cooled to room temperature to obtain the catalyst ZnCeZrO x 150 mg of ZnCeZrO xMix 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, pelletize by tabletting, with a particle size of 20-40 mesh. Weigh 150 mg and load it into a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C, and in an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0050] Example 17: GaCeZrO x (Volatile precipitant: ammonia water) Weigh 0.9974 g of gallium nitrate, 1.1333 g of cerium nitrate, and 10.0847 g of zirconium nitrate, dissolve them in 300 g of deionized water and ultrasonically obtain a clear solution. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a closed container, let it stand and crystallize for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst GaCeZrO x 。150 mg of GaCeZrO x Mix 150 mg of GaCeZrO with 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, pelletize by tabletting, with a particle size of 20-40 mesh. Weigh 150 mg and load it into a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C, and in an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0051] Example 18: InCeZrO x (Volatile precipitant: ammonia water) Weigh 1.3838 g of indium nitrate, 1.1333 g of cerium nitrate, and 10.0847 g of zirconium nitrate, dissolve them in 300 g of deionized water and ultrasonically obtain a clear solution. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a closed container, let it stand and crystallize for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst InCeZrO x 。150 mg of InCeZrO xMix 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, pelletize by tableting, with a particle size of 20 - 40 mesh. Weigh 150 mg and load it into a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C under an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under reaction conditions of 3 MPa and 380 °C.

[0052] Example 19: ZnGaZrO x (Volatile precipitant: ammonia water) Weigh 1.1602 g of zinc nitrate, 0.6675 g of gallium nitrate, and 10.0847 g of zirconium nitrate, dissolve them in 300 g of deionized water and obtain a clear solution by ultrasonic treatment. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a sealed container, stand for crystallization for 100 h, filter, wash three times with deionized water, dry overnight at 110 °C, calcine in air atmosphere at 300 °C for 1 h, calcine at 500 °C for 3 h, and cool to room temperature to obtain the catalyst ZnGaZrO x 。150 mg of ZnGaZrO x Mix 150 mg of ZnGaZrO with 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, pelletize by tableting, with a particle size of 20 - 40 mesh. Weigh 150 mg and load it into a quartz tube. Pretreat it for 2 hours at normal pressure, 400 °C under an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under reaction conditions of 3 MPa and 380 °C.

[0053] Example 20: ZnSmZrO x (Volatile precipitant: ammonia water) Weigh 1.1602 g of zinc nitrate, 1.3118 g of samarium nitrate, and 10.0847 g of zirconium nitrate, dissolve them in 300 g of deionized water and obtain a clear solution by ultrasonic treatment. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a sealed container, stand for crystallization for 100 h, filter, wash three times with deionized water, dry overnight at 110 °C, calcine in air atmosphere at 300 °C for 1 h, calcine at 500 °C for 3 h, and cool to room temperature to obtain the catalyst ZnSmZrO x 。150 mg of ZnSmZrO xIt was ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), tableted and granulated to a particle size of 20-40 mesh. 150 mg was weighed and loaded into a quartz tube, pretreated under normal pressure at 400 °C in an argon atmosphere for 2 hours. Subsequently, a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, the flow rate was controlled at 15 mL / min, and the reaction was carried out under the reaction conditions of 3 MPa and 380 °C for 16 hours.

[0054] Example 21: ZnGa2O4 (Volatile precipitant: ammonia water) 4.4624 g of zinc nitrate and 3.8361 g of gallium nitrate were dissolved in 300 g of deionized water and ultrasonicated to obtain a clear solution. 79.4 g of ammonia water was diluted to 300 g of deionized water. The two solutions were transferred to a closed container, left to crystallize for 100 h, filtered, washed three times with deionized water, dried overnight at 110 °C, calcined in an air atmosphere at 300 °C for 1 h, calcined at 500 °C for 3 h, and cooled to room temperature to obtain the catalyst ZnGa2O4. 150 mg of ZnGa2O4 was ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), tableted and granulated to a particle size of 20-40 mesh. 150 mg was weighed and loaded into a quartz tube, pretreated under normal pressure at 400 °C in an argon atmosphere for 2 hours. Subsequently, a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, the flow rate was controlled at 15 mL / min, and the reaction was carried out under the reaction conditions of 3 MPa and 380 °C for 16 hours.

[0055] Example 22: ZnCr2O4 (Volatile precipitant: ammonia water) 4.4624 g of zinc nitrate and 6.0629 g of chromium nitrate were dissolved in 300 g of deionized water and ultrasonicated to obtain a clear solution. 79.4 g of ammonia water was diluted to 300 g of deionized water. The two solutions were transferred to a closed container, left to crystallize for 100 h, filtered, washed three times with deionized water, dried overnight at 110 °C, calcined in an air atmosphere at 300 °C for 1 h, calcined at 500 °C for 3 h, and cooled to room temperature to obtain the catalyst ZnCr2O4. 150 mg of ZnCr2O4 was ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), tableted and granulated to a particle size of 20-40 mesh. 150 mg was weighed and loaded into a quartz tube, pretreated under normal pressure at 400 °C in an argon atmosphere for 2 hours. Subsequently, a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, the flow rate was controlled at 15 mL / min, and the reaction was carried out under the reaction conditions of 3 MPa and 380 °C for 16 hours.

[0056] Example 23: ZnAl2O4 (Volatile precipitant: ammonia water) Weigh 4.4624 g of zinc nitrate and 5.6270 g of aluminum nitrate, dissolve them in 300 g of deionized water, and obtain a clear solution by ultrasonic treatment. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a sealed container, let it stand for crystallization for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, then calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZnAl2O4. Grind and mix 150 mg of ZnAl2O4 with 150 mg of SAPO-34 (Si / Al = 0.075), press and granulate it, with a particle size of 20 - 40 mesh. Weigh 150 mg and load it into a quartz tube, pretreat it for 2 hours at normal pressure, 400 °C, and in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate to be 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0057] It should be noted that the data of carbon dioxide conversion rate, carbon monoxide selectivity, light olefin selectivity, and light olefin yield provided in the embodiments of the present invention are calculated according to the following formulas:

[0058]

[0059]

[0060]

[0061] X(CO2) represents the CO2 conversion rate, S(CO) represents the CO selectivity, S(C n H m ) represents the hydrocarbon selectivity, Y(C n H m ) represents the hydrocarbon yield.

[0062] Taking Example 1 as an example, where is the content of CO2 in the gas as the reaction raw material (i.e., introducing a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen), which is 24% in this example, is the content of N2 in the gas as the reaction raw material, which is 4% in this example; , , are all obtained from the TCD, is the content of CO2 in the TCD, is the content of CO in the TCD, is the content of N2 in the TCD. In this example, and , are 21.01%, 2.41%, and 4.34% respectively; The value of is the total content of all hydrocarbons and oxygenated compounds in the FID; According to the above data, substituting them into the formulas for hydrocarbon selectivity and yield, the selectivity and yield data of light olefins can be calculated; It should be noted that the calculated data needs to be corrected to a certain extent. There are mainly two correction factors: one is that the true composition of the mixed gas in the gas cylinder needs to be determined by gas chromatography before the reaction (the gas parameters marked on the raw material gas cylinders obtained commercially are not accurate enough for fine calculations); the other is that during the reaction process, since the reaction is a reaction with a volume reduction, the flow rate needs to be corrected using nitrogen as an internal standard.

[0063] The subsequent examples are calculated using the same calculation method.

[0064] Specific surface area: The test instrument is Micromeritics ASAP 2020 PLUS. After in-situ vacuum for 6 h at 623 K, nitrogen adsorption-desorption analysis is carried out. The total pore volume is determined by the adsorption capacity at P / P0 = 0.99, and the total surface area and micropore volume are calculated by the BET method and t-plot method respectively.

[0065] Table 1 Carbon dioxide conversion rate, carbon monoxide selectivity, light olefin selectivity, and light olefin yield of Examples 1 - 23

[0066] As shown in Table 1, Table 1 shows the carbon dioxide conversion rate, carbon monoxide selectivity, light olefin selectivity, and light olefin yield obtained by using composite catalysts obtained by coupling binary or ternary metal oxides with a solid solution or spinel structure of different precipitants and different element combinations with SAPO-34 (Si / Al = 0.075) for the reaction of carbon dioxide hydrogenation to light olefins. The results show that the CO2 conversion rate with ammonia water as the precipitant is the highest, the CO selectivity with di-n-butylamine as the precipitant is the lowest, the light olefin selectivity with di-n-butylamine as the precipitant is the highest. Considering the light olefin yield comprehensively, ammonia water as the precipitant is the optimal solution; InZrO x , InCeZrO x , ZnCr2O4 have a high carbon dioxide conversion rate, but the reverse water-gas shift reaction is relatively intense, and the main product is carbon monoxide. GaZrO x , GaCeZrO x , ZnGaZrO x , ZnCeZrO x , ZnSmZrOx It has a high carbon dioxide conversion rate, but it is difficult to achieve both high carbon monoxide selectivity and high light olefin selectivity. ZnGa2O4 has a strong hydrogenation ability, resulting in a high carbon dioxide conversion rate. At the same time, it can also inhibit the reverse water-gas shift reaction. However, light olefins will be further converted into alkanes due to the strong hydrogenation ability. ZnAl2O4 can effectively inhibit the reverse water-gas shift reaction and has a high light olefin selectivity, but its low carbon dioxide conversion rate leads to a low light olefin yield. ZnZrO x It has a high carbon dioxide conversion rate and can effectively inhibit the reverse water-gas shift reaction. Due to its relatively mild hydrogenation ability, it can also obtain a high light olefin selectivity, thus achieving a high light olefin yield.

[0067] Example 24: ZrO2 / SAPO-34 Weigh 12.8796 g of zirconium nitrate and dissolve it in 300 g of deionized water, and obtain a clear solution by ultrasonic treatment. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a sealed container, let it stand for crystallization for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZrO2. Grind and mix 150 mg of ZrO2 with 150 mg of SAPO-34 (Si / Al = 0.075), press and granulate it, with a particle size of 20 - 40 mesh. Weigh 150 mg and put it into a quartz tube, pretreat it for 2 hours at normal pressure, 400 °C in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0068] Example 25: Zn6Zr 94 O x / SAPO-34 Weigh 0.5355 g of zinc nitrate and 12.1068 g of zirconium nitrate and dissolve them in 300 g of deionized water, and obtain a clear solution by ultrasonic treatment. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a sealed container, let it stand for crystallization for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst Zn6Zr 94 O x . 150 mg of Zn6Zr 94 O xMix 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, pelletize by tabletting, with a particle size of 20 - 40 mesh. Weigh 150 mg and load it into a quartz tube. Pretreat it for 2 hours under normal pressure, at 400 °C, in an argon atmosphere. Subsequently, introduce a feed gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0069] Example 26: Zn 25 Zr 75 O x / SAPO-34 Weigh 2.2312 g of zinc nitrate and 9.6597 g of zirconium nitrate, dissolve them in 300 g of deionized water and sonicate to obtain a clear solution. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a sealed container, let it stand for crystallization for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it in an air atmosphere at 300 °C for 1 h and at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst Zn 25 Zr 75 O x . 150 mg of Zn 25 Zr 75 O x Mix 150 mg of Zn

[0070] Zr 40 Zr 60 O x / SAPO-34 Weigh 3.5699 g of zinc nitrate and 7.7278 g of zirconium nitrate, dissolve them in 300 g of deionized water and sonicate to obtain a clear solution. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a sealed container, let it stand for crystallization for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it in an air atmosphere at 300 °C for 1 h and at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst Zn 40 Zr 60 O x . 150 mg of Zn 40 Zr60 O x It was ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), tableted and granulated with a particle size of 20 - 40 mesh. 150 mg was weighed and placed into a quartz tube, and pre-treated under normal pressure, at 400 °C, in an argon atmosphere for 2 hours. Subsequently, a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, the flow rate was controlled at 15 mL / min, and the reaction was carried out under the reaction conditions of 3 MPa and 380 °C for 16 hours.

[0071] Example 28: Zn 60 Zr 40 O x / SAPO-34 5.3548 g of zinc nitrate and 5.1518 g of zirconium nitrate were dissolved in 300 g of deionized water and ultrasonicated to obtain a clear solution. 79.4 g of ammonia water was diluted to 300 g of deionized water. The two solutions were transferred to a closed container, allowed to crystallize statically for 100 h, filtered, washed three times with deionized water, dried overnight at 110 °C, calcined in air atmosphere at 300 °C for 1 h, calcined at 500 °C for 3 h, and cooled to room temperature to obtain the catalyst Zn 60 Zr 40 O x . 150 mg of Zn 60 Zr 40 O x It was ground and mixed with 150 mg of SAPO-34 (Si / Al = 0.075), tableted and granulated with a particle size of 20 - 40 mesh. 150 mg was weighed and placed into a quartz tube, and pre-treated under normal pressure, at 400 °C, in an argon atmosphere for 2 hours. Subsequently, a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, the flow rate was controlled at 15 mL / min, and the reaction was carried out under the reaction conditions of 3 MPa and 380 °C for 16 hours.

[0072] Example 29: ZnO / SAPO-34 Weigh 8.9247 g of zinc nitrate and dissolve it in 300 g of deionized water, then ultrasonically treat it to obtain a clear solution. Weigh 79.4 g of ammonia water and dilute it to 300 g of deionized water. Transfer the two solutions to a sealed container, let it stand and crystallize for 100 h, filter, wash it three times with deionized water, dry it overnight at 110 °C, calcine it at 300 °C for 1 h in an air atmosphere, then calcine it at 500 °C for 3 h, and cool it to room temperature to obtain the catalyst ZnO. Grind and mix 150 mg of ZnO with 150 mg of SAPO-34 (Si / Al = 0.075), pelletize it, with a particle size of 20 - 40 mesh. Weigh 150 mg and put it into a quartz tube, pretreat it for 2 h at normal pressure, 400 °C, and in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 h under the reaction conditions of 3 MPa and 380 °C.

[0073] Comparative Example 1: Zn 25 Zr 75 O x -CP / SAPO-34 (co-precipitation method) Weigh 150 mg of Zn 25 Zr 75 O x -CP and 150 mg of SAPO-34 (Si / Al = 0.075) are ground and mixed, pelletized, with a particle size of 20 - 40 mesh. Weigh 150 mg and put it into a quartz tube, pretreat it for 2 h at normal pressure, 400 °C, and in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 h under the reaction conditions of 3 MPa and 380 °C.

[0074] Comparative Example 2: Zn 25 Zr 75 O x -IM / SAPO-34 (impregnation method) Weigh 150 mg of Zn 25 Zr 75 O x -IM and 150 mg of SAPO-34 (Si / Al = 0.075) are ground and mixed, pelletized, with a particle size of 20 - 40 mesh. Weigh 150 mg and put it into a quartz tube, pretreat it for 2 h at normal pressure, 400 °C, and in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 h under the reaction conditions of 3 MPa and 380 °C.

[0075] Comparative Example 3: Zn 25 Zr 75 O x -SG / SAPO-34 (Sol-Gel Method) Weigh 150 mg of Zn 25 Zr 75 O x -SG and 150 mg of SAPO-34 (Si / Al = 0.075) are ground and mixed, pelletized, with a particle size of 20 - 40 mesh. Weigh 150 mg and place it in a quartz tube. Pretreat it under normal pressure, at 400 °C, in an argon atmosphere for 2 hours. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react under reaction conditions of 3 MPa and 380 °C for 16 hours.

[0076] Comparative Example 4: Zn 25 Zr 75 O x -BM / SAPO-34 (Ball Milling Method) Weigh 150 mg of Zn 25 Zr 75 O x -BM and 150 mg of SAPO-34 (Si / Al = 0.075) are ground and mixed, pelletized, with a particle size of 20 - 40 mesh. Weigh 150 mg and place it in a quartz tube. Pretreat it under normal pressure, at 400 °C, in an argon atmosphere for 2 hours. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react under reaction conditions of 3 MPa and 380 °C for 16 hours.

[0077] Table 2 Carbon Dioxide Conversion Rate, Carbon Monoxide Selectivity, Light Olefin Selectivity, and Light Olefin Yield of Examples 24 - 29 and Comparative Examples 1 - 4

[0078] As shown in Table 2, Table 2 shows the carbon dioxide conversion rate, carbon monoxide selectivity, light olefin selectivity, and light olefin yield obtained from the reaction of a composite catalyst obtained by coupling metal oxides with different zinc contents with SAPO-34 (Si / Al = 0.075) for the hydrogenation of carbon dioxide to light olefins. The results show that the abilities of metal oxides with different zinc contents to activate carbon dioxide and dissociate hydrogen are different. Considering Zn 25 Zr 75 O xIt has the strongest ability to activate carbon dioxide and dissociate hydrogen, so the yield of light olefins is the highest. Because the gas diffusion method has a large specific surface area, the catalytic performance is better than that of the comparative example within a wide range of active metal contents.

[0079] Example 30: The same composite catalyst as in Example 26 was used, the reaction pressure was 1 MPa, and the others were the same as in Example 26.

[0080] Example 31: The same composite catalyst as in Example 26 was used, the reaction pressure was 2 MPa, and the others were the same as in Example 26.

[0081] Example 32: The same composite catalyst as in Example 26 was used, the reaction pressure was 4 MPa, and the others were the same as in Example 26.

[0082] Example 33: The same composite catalyst as in Example 26 was used, the reaction temperature was 340 °C, and the others were the same as in Example 26.

[0083] Example 34: The same composite catalyst as in Example 26 was used, the reaction temperature was 360 °C, and the others were the same as in Example 26.

[0084] Example 35: The same composite catalyst as in Example 26 was used, the reaction temperature was 400 °C, and the others were the same as in Example 26.

[0085] Example 36: The same composite catalyst as in Example 26 was used, the reaction temperature was 420 °C, and the others were the same as in Example 26.

[0086] Example 37: The same composite catalyst as in Example 26 was used. After the Ar pretreatment was completed, carbon dioxide with a volume percentage of 19.2%, hydrogen with a volume percentage of 76.8%, and nitrogen with a volume percentage of 4% were introduced, and the others were the same as in Example 26.

[0087] Example 38: The same composite catalyst as in Example 26 was used. After the Ar pretreatment was completed, carbon dioxide with a volume percentage of 16%, hydrogen with a volume percentage of 80%, and nitrogen with a volume percentage of 4% were introduced, and the others were the same as in Example 26.

[0088] Example 39: The same composite catalyst as in Example 26 was used. After the Ar pretreatment was completed, carbon dioxide with a volume percentage of 14%, hydrogen with a volume percentage of 82%, and nitrogen with a volume percentage of 4% were introduced, and the others were the same as in Example 26.

[0089] Example 40: The same composite catalyst as in Example 26 was used, and the reaction space velocity was 1500 mL / (g cat h), and the others were the same as in Example 26.

[0090] Example 41: The same composite catalyst as in Example 26 was used, and the reaction space velocity was 3000 mL / (g cat h), and the others were the same as in Example 26.

[0091] Example 42: The same composite catalyst as in Example 26 was used, and the reaction space velocity was 4500 mL / (g cat h), and the others were the same as in Example 26.

[0092] Example 43: The same composite catalyst as in Example 26 was used, and the reaction space velocity was 9000 mL / (g cat h), and the others were the same as in Example 26.

[0093] Example 44: The same composite catalyst as in Example 26 was used, and 100 mg of Zn 25 Zr 75 O x was ground and mixed with 200 mg of SAPO-34 (Si / Al = 0.075), and the others were the same as in Example 26.

[0094] Example 45: The same composite catalyst as in Example 26 was used, and 200 mg of Zn 25 Zr 75 O x was ground and mixed with 100 mg of SAPO-34 (Si / Al = 0.075), and the others were the same as in Example 26.

[0095] Example 46: The same composite catalyst as in Example 26 was used, and 240 mg of Zn 25 Zr 75 O x was ground and mixed with 60 mg of SAPO-34 (Si / Al = 0.075), and the others were the same as in Example 26.

[0096] Example 47: ZnZrO x and SAPO-34 (Si / Al = 0.075) were respectively pelletized, with a particle size of 20-40 mesh. 75 mg of each was weighed and placed into a quartz tube, separated by quartz sand in the middle. Pretreatment was carried out for 2 hours under normal pressure, at 400 °C, in an argon atmosphere. Subsequently, a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen was introduced, and the flow rate was controlled at 15 mL / min. Under the reaction conditions of 3 MPa and 380 °C, the reaction was carried out for 16 hours.

[0097] Example 48: ZnZrO xTabletting and granulating with SAPO-34 (Si / Al = 0.075) respectively, with a particle size of 20-40 mesh. Weigh 75 mg of each, mix them evenly, and put them into a quartz tube. Pretreat for 2 hours under normal pressure, at 400 °C, and in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0098] Example 49: Weigh 150 mg of ZnZrO x Mix 150 mg of it with 150 mg of SAPO-34 (Si / Al = 0.075) on a shaker, tablet and granulate with a particle size of 20-40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat for 2 hours under normal pressure, at 400 °C, and in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0099] Example 50: Weigh 150 mg of ZnZrO x Mix 150 mg of it with 150 mg of SAPO-34 (Si / Al = 0.075) by ball milling, tablet and granulate with a particle size of 20-40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat for 2 hours under normal pressure, at 400 °C, and in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 24% carbon dioxide, 72% hydrogen, and 4% nitrogen, control the flow rate at 15 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0100] Example 51: Weigh 150 mg of Zn 25 Zr 75 O x Mix 150 mg of it with 150 mg of SAPO-34 (Si / Al = 0.075) by grinding, tablet and granulate with a particle size of 20-40 mesh. Weigh 150 mg and put it into a quartz tube. Pretreat for 2 hours under normal pressure, at 400 °C, and in an argon atmosphere. Subsequently, introduce a raw material gas with a volume percentage of 14% carbon dioxide, 82% hydrogen, and 4% nitrogen, control the flow rate at 7.5 mL / min, and react for 16 hours under the reaction conditions of 3 MPa and 380 °C.

[0101] Table 3 Carbon dioxide conversion rate, carbon monoxide selectivity, light olefin selectivity, and light olefin yield in Examples 30-51 As shown in Table 3, Table 3 shows the carbon dioxide conversion rate, carbon monoxide selectivity, light olefin selectivity, and light olefin yield under different reaction pressures, reaction temperatures, volume ratios of carbon dioxide to hydrogen, space velocities, and mixing ratios of metal oxides to molecular sieves. The optimal reaction conditions for the reaction of carbon dioxide hydrogenation to light olefins using the ZnZrO x / SAPO-34 (Si / Al = 0.075) composite catalyst were determined through the above results.

[0103] The above are only the preferred embodiments of the present invention and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent transformations made to the above embodiments based on the technical essence of the present invention all fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a metal oxide - molecular sieve composite catalyst, characterized in that: The metal oxide - molecular sieve composite catalyst comprises a metal oxide and a molecular sieve; The metal oxide is a solid - solution metal oxide or a spinel - type metal oxide composed of three or two of the metal elements M1, M2, and M3, where M1 is one of Zn, Ga, and In, M2 is one of Ce, Sm, La, and Fe, and M3 is one of Zr, Ga, Cr, Al, and Ti; The framework composition of the molecular sieve is a tetrahedron of silicon - aluminum - oxygen or silicon - phosphorus - aluminum - oxygen; The metal oxide is prepared by a gas diffusion method.

2. The preparation method according to claim 1, characterized in that: The metal oxide is prepared by a gas diffusion method, specifically, a volatile precipitant enters a metal precursor solution in a gas - phase transport manner to prepare the metal oxide. The metal precursor solution is a mixed solution of two metal salts or a mixed solution of three metal salts. In the mixed solution of two metal salts, the molar ratio of M1 to M3 is any value among 0, 0.1, 0.2, 0.3, 0.4, 0.5, 1 or a range value between any two of them; in the mixed solution of three metal salts, the molar ratio of M1 to (M2 + M3) is any value among 0.1, 0.2, 0.3, 0.4, 0.5, 1 or a range value between any two of them; in the mixed solution of three metal salts, the molar ratio of M2 to M3 is any value among 0.1, 0.2, 0.3, 0.4, 0.5, 1 or a range value between any two of them; The volatile precipitant includes one or a mixture of two of ammonia water, ethylenediamine, diethylamine, triethylamine, dipropylamine, isopropylamine, 1,2 - propanediamine, n - butylamine, isobutylamine, sec - butylamine, tert - butylamine, di - n - butylamine, and 1,4 - butanediamine.

3. The preparation method according to claim 2, characterized in that, The metal precursor solution is a mixed solution formed by one or several of metal nitrates, metal sulfates, and metal carbonates.

4. The preparation method according to claim 2, characterized in that, The metal precursor solution is a mixed solution formed by one or several of zinc nitrate, zirconium nitrate, gallium nitrate, indium nitrate, cerium nitrate, samarium nitrate, chromium nitrate, and aluminum nitrate.

5. The preparation method according to claim 1 or 2, characterized in that: The crystallization time required for the gas diffusion method is 0 - 200 hours; the required calcination atmosphere is one of argon, air, and 10% hydrogen / argon; the required calcination temperature is 400 - 900 °C; the required calcination time is 0.1 - 12 h.

6. The preparation method according to claim 1 or 2, characterized in that: The metal oxides include ZnZrO x , GaZrO x , InZrO x , ZnCeZrO x , GaCeZrO x , InCeZrO x , ZnGaZrO x , ZnSmZrO x , ZnGa2O4, ZnCr2O4, ZnAl2O4; the molecular sieves include SAPO-34, SAPO-18 aluminosilicate phosphates or silicoaluminophosphate molecular sieve SSZ-13.

7. The preparation method according to claim 1, wherein The mixing method of the metal oxide and the molecular sieve is one of double - bed mixing, particle mixing, ball - milling mixing, and powder mixing.

8. A method for preparing olefins by hydrogenating carbon dioxide, characterized in that, The method uses a metal oxide - molecular sieve composite catalyst, and the metal oxide - molecular sieve composite catalyst is the metal oxide - molecular sieve composite catalyst prepared according to any one of claims 1 - 5.

9. The method according to claim 8, wherein: Using a mixed gas containing carbon dioxide and hydrogen as the raw material gas, a reaction occurs under the condition of reaction pressure, and the catalyst used in the reaction is the metal oxide - molecular sieve composite catalyst obtained according to claims 1 - 6.

10. The method according to claim 8, wherein The reaction conditions of the method include: Reaction temperature: 320 °C - 440 °C; Reaction pressure: 1 MPa - 6 MPa; The volume ratio of hydrogen to carbon dioxide is 3 / 1 to 6 / 1; reaction space velocity: 1500 to 20000 mL / (g cat h); Mass ratio of metal oxide to molecular sieve in mixture: 3 / 1 to 1 / 3; Preferred reaction temperature: 360 °C to 400 °C; Reaction pressure: 1 MPa to 4 MPa; The volume ratio of hydrogen to carbon dioxide is 3 / 1 to 6 / 1; reaction space velocity: 3000 to 9000 mL / (g cat h); Mass ratio of metal oxide to molecular sieve in mixture: 2 / 1 to 1 / 2.

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