Catalysts for the direct production of aviation kerosene from carbon dioxide and hydrogen, their preparation methods and applications

Abstract

This disclosure relates to a catalyst for the direct production of aviation kerosene from carbon dioxide and hydrogen, its preparation method, and its application. Based on the total weight of the catalyst, the catalyst comprises: 10-50% by weight of an active component, 0.05-15% by weight of an auxiliary component, and the balance being a support. The active component includes Co; the auxiliary component is selected from one or more transition metals and alkali metals; the support includes TiO2; and the contents of the active component and auxiliary component are in the form of metal oxides. The catalyst provided by this disclosure exhibits high activity, high selectivity for the target product, and good catalyst stability.

Description

Technical Field

[0001] This disclosure relates to the field of catalyst technology, and more specifically, to a catalyst for the direct production of aviation kerosene from carbon dioxide and hydrogen, a method for its preparation, and its application. Background Technology

[0002] Aviation kerosene, as a fuel for aviation turbine engines, has advantages such as suitable density, high calorific value, good combustion performance, low carbon deposits, good low-temperature fluidity, good thermal stability and oxidation stability, high cleanliness, and low corrosion to engine parts. It is suitable for use in gas turbine engines and ramjet engines and is widely used in civil and military aircraft.

[0003] Carbon dioxide (CO2) is a greenhouse gas. A circular model that utilizes CO2 captured from industrial waste gases or the atmosphere to produce hydrogen using renewable energy, and then catalytically hydrogenates CO2 to produce liquid hydrocarbons, is of great significance for simultaneously addressing the two major new challenges facing human society today: climate change and the energy crisis.

[0004] Current research on CO2 hydrogenation mainly focuses on low-molecular-weight hydrocarbons or oxygen-containing compounds such as methanol (e.g., CN201110006073.8), dimethyl ether (e.g., CN201410495290.1), methane (e.g., CN201210444697.2), and low-carbon olefins (e.g., CN201510102620.0). Research on the preparation of long-chain hydrocarbons via CO2 hydrogenation is relatively limited. Direct synthesis of aviation kerosene fraction hydrocarbons (C8-) from carbon dioxide hydrogenation is also less common. 16 Research on hydrocarbons has not yet made any major breakthroughs. Gao Peng et al. from the Shanghai Advanced Research Institute (Nat. Chem. 2017, 9, 1019-1024) obtained a composite catalyst by mixing In2O3 with HZSM-5, which can produce liquid hydrocarbons by hydrogenation of CO2. However, the selectivity of the byproduct CO is higher than 50%, resulting in a low space-time yield of the product.

[0005] Therefore, the existing carbon dioxide hydrogenation process for producing aviation kerosene has a low yield of hydrocarbons in the target product, aviation kerosene distillate, but high selectivity for byproducts CO and methane. Summary of the Invention

[0006] The purpose of this disclosure is to provide a catalyst for the direct production of aviation kerosene from carbon dioxide and hydrogen, its preparation method and application, which has high catalyst activity, high selectivity for target products and good reaction stability.

[0007] To achieve the above objectives, the first aspect of this disclosure provides a catalyst for the direct production of aviation kerosene from carbon dioxide and hydrogen. Based on the total weight of the catalyst, the catalyst comprises: 10-50% by weight of an active component, 0.05-15% by weight of an auxiliary component, and the balance being a support; wherein the active component includes Co; the auxiliary component is selected from one or more transition metals and alkali metals; and the support comprises TiO2; wherein the contents of the active component and the auxiliary component are in the form of metal oxides.

[0008] Optionally, based on the total weight of the catalyst, the catalyst comprises: 10-40% by weight of active component, 0.05-10% by weight of auxiliary component and the balance of support; preferably, the catalyst comprises: 10-40% by weight of active component, 0.05-8% by weight of auxiliary component and the balance of support. Preferably, the auxiliary component is selected from one or more of iron, manganese, cerium, vanadium, lanthanum, zirconium, sodium, and potassium; more preferably, it is selected from one or more of iron, manganese, cerium, sodium, and potassium.

[0009] Optionally, the TiO2 support comprises rutile phase and anatase phase; based on the total weight of the TiO2 support, the content of anatase phase is 50% by weight or more, preferably 65-90% by weight.

[0010] Optionally, the catalyst has a BET specific surface area of ​​20-100 m². 2 / g, average pore size 5-30nm, pore volume 0.05-1.0cm³ 3 / g; preferably, the BET specific surface area of ​​the catalyst is 25-100m². 2 / g, average pore size 5-25nm, pore volume 0.1-1.0cm³ 3 / g.

[0011] A second aspect of this disclosure provides a method for preparing a catalyst as described in the first aspect of this disclosure, comprising the following steps: S1. Mix the carrier with water to obtain a carrier suspension; mix the active component source, the auxiliary component source, and the solvent to obtain a mixed solution; S2. The mixed solution, the first alkaline precipitant, and the carrier suspension are mixed to carry out a first precipitation reaction and a first aging treatment to obtain a solid product; S3. The solid product is subjected to a first washing treatment, a first filtration treatment, a first drying treatment, and a first calcination treatment.

[0012] Optionally, the molar ratio of the carrier raw material: active component source: auxiliary component source: first alkaline precipitant is 1:0.25-4.0:0.12-2.0:1.5-12, preferably 1:0.25-3.0:0.12-1.5:1.5-10; Optionally, the molar ratio of the carrier material to water is 1:3.0-9.0, preferably 1:4.0-9.0; Optionally, the total concentration of the active component source and the auxiliary component source in the mixed solution is 0.2-4.0 mol / L, preferably 0.5-3 mol / L.

[0013] Optionally, in step S1, the active component source is selected from one or more of cobalt chloride, cobalt nitrate, cobalt acetate, cobalt carbonate, and cobalt sulfate; preferably, the active component source is selected from one or more of cobalt nitrate, cobalt chloride, and cobalt acetate. The auxiliary agent component source is selected from one or more water-soluble salts of auxiliary metal elements; preferably, the auxiliary agent component source is selected from one or more of ferric nitrate, ferric chloride, manganese nitrate, manganese acetate, cerium nitrate, cerium acetate, ammonium metavanadate, lanthanum nitrate, zirconium oxynitrate, zirconium nitrate, zirconium oxychloride, sodium chloride, sodium nitrate, and potassium nitrate; preferably, the auxiliary agent component source is selected from one or more of ferric nitrate, ferric chloride, manganese nitrate, manganese acetate, cerium nitrate, cerium acetate, sodium chloride, sodium nitrate, and potassium nitrate. The solvent is selected from one or more of water and alcohols; the alcohols include one or more of ethanol and ethylene glycol. The first alkaline precipitant is selected from one or more of ammonia, ammonium carbonate, urea and ammonium bicarbonate; optionally, the first alkaline precipitant is used in the form of a 0.5-3 mol / L aqueous solution.

[0014] Optionally, in step S2, the conditions for the first precipitation reaction include: a reaction temperature of 20-80℃, preferably 20-60℃; a reaction time of 2-12h, preferably 2-8h; and a pH value of 6.0-10.0, preferably 7.5-10.0. The conditions for the first aging treatment include: an aging temperature of 20-100℃, preferably 30-80℃; and an aging time of 2-48h, preferably 6-24h.

[0015] Optionally, in step S3, the conditions for the first drying treatment include: a drying temperature of 80-150℃, preferably 100-120℃, and a drying time of 2-24h, preferably 2-12h. The conditions for the first calcination treatment include: a calcination temperature of 300-700℃, preferably 350-700℃, a calcination time of 2-24h, preferably 4-12h, and a calcination atmosphere of air.

[0016] Optionally, the carrier raw material is prepared by a method comprising the following steps: The solution containing the titanium precursor is contacted with a second alkaline precipitant to carry out a second precipitation reaction and a second aging treatment; the precipitate is then subjected to a second washing treatment, a second drying treatment, and a second calcination treatment. Preferably, the molar ratio of the titanium precursor to the second alkaline precipitant is 1:0.5-3.0, more preferably 1:1.0-3.0; optionally, the concentration of the titanium precursor in the solution containing the titanium precursor is 0.05-3.0 mol / L, more preferably 0.05-2.0 mol / L. Preferably, the conditions for the second precipitation reaction include: a reaction temperature of 20-100℃, preferably 20-60℃; a reaction time of 2-24h, preferably 2-8h; and a pH value of 5.0-10.0, preferably 6.5-9.0. Preferably, the conditions for the second aging treatment include: an aging temperature of 20-100℃, preferably 30-80℃; and an aging time of 2-24h, preferably 4-12h. Preferably, the conditions for the second drying treatment include: a drying temperature of 80-150℃, more preferably 100-120℃, and a drying time of 2-24h, more preferably 2-12h; Preferably, the conditions for the second calcination treatment include: a calcination temperature of 300-700℃, preferably 400-600℃; a calcination time of 2-24h, preferably 4-12h; and a calcination atmosphere of air. Optionally, the titanium precursor is selected from one or more of titanium tetrachloride, tetrabutyl titanate, and titanium oxysulfate; The second alkaline precipitant is selected from one or more of ammonia, ammonium carbonate, ammonium bicarbonate and urea. Preferably, the concentration of the second alkaline precipitant is 0.5-3 mol / L.

[0017] This third aspect of the disclosure provides the application of the catalyst as described in the first aspect of the disclosure in the reaction for the direct production of aviation kerosene from carbon dioxide and hydrogen.

[0018] Optionally, the reaction for directly producing aviation kerosene from carbon dioxide and hydrogen includes the following steps: activating the catalyst; contacting the activated catalyst with carbon dioxide and hydrogen to carry out a catalytic reaction; preferably, the activation conditions include: activation temperature of 200-450℃, activation time of 2-24h, activation pressure of 0-2MPa, and activation atmosphere selected from one or more of CO, CO2, and H2; preferably, the activation temperature is 200-400℃, activation time is 4-12h, and activation pressure is 0-1.0MPa; the Co element in the activated catalyst is selected from one or more of Co, CoO, and Co2C; preferably, the catalytic reaction conditions include: a molar ratio of H2 / CO2 of 1-4, preferably 2-3.5; and a volume hourly space velocity of 1000-10000h⁻¹. -1 Preferably 1500-8000h -1 The reaction temperature is 200-450℃ and the reaction pressure is 1-5MPa; preferably, the reaction temperature is 215-400℃ and the reaction pressure is 2-4MPa.

[0019] Through the above technical solution, this disclosure provides a catalyst for the direct production of aviation kerosene from carbon dioxide and hydrogen, its preparation method, and its application. This catalyst is suitable for the one-step hydrogenation of carbon dioxide to C 8+ Aviation kerosene, this catalyst has excellent catalytic performance, high catalyst activity, high selectivity for target products and good reaction stability.

[0020] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 The XRD patterns are those of the catalysts prepared in Examples 1 and 9 of this disclosure. Detailed Implementation

[0022] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0023] The first aspect of this disclosure provides a catalyst for the direct production of aviation kerosene from carbon dioxide and hydrogen. Based on the total weight of the catalyst, the catalyst comprises: 10-50% by weight of an active component, 0.05-15% by weight of an auxiliary component, and the balance being a support; wherein the active component includes Co; the auxiliary component is selected from one or more transition metals and alkali metals; and the support comprises TiO2; wherein the contents of the active component and the auxiliary component are in the form of metal oxides.

[0024] This disclosure provides a catalyst for the direct production of aviation kerosene from carbon dioxide and hydrogen, which is adapted for one-step hydrogenation of carbon dioxide to C 8+ Aviation kerosene, this catalyst has excellent catalytic performance, high catalyst activity, high selectivity for target products and good reaction stability.

[0025] In a preferred embodiment, based on the total weight of the catalyst, the catalyst comprises: 10-40% by weight of active component, 0.05-10% by weight of promoter component, and the balance being a support; preferably, the catalyst comprises: 10-40% by weight of active component, 0.05-8% by weight of promoter component, and the balance being a support. When the component content of the catalyst is within the preferred range in this embodiment, the catalyst exhibits better catalytic activity and catalytic stability.

[0026] In one embodiment, the auxiliary component is selected from one or more of iron, manganese, cerium, vanadium, lanthanum, zirconium, sodium, and potassium; more preferably, it is selected from one or more of iron, manganese, cerium, sodium, and potassium. This disclosure utilizes the auxiliary component in conjunction with the active component Co and the support to achieve higher catalyst activity and target product selectivity in the reaction of directly producing aviation kerosene from carbon dioxide and hydrogen.

[0027] In a preferred embodiment, the TiO2 support comprises a rutile phase and anatase phase; based on the total weight of the TiO2 support, the anatase phase content is 50% by weight or more, preferably 65-90% by weight. When the anatase phase content in the TiO2 support is within the range of this embodiment, especially within the preferred range, the catalytic activity and catalytic stability of the catalyst can be improved.

[0028] In one specific embodiment, the catalyst has a BET specific surface area of ​​20-100 m². 2 / g, average pore size 5-30nm, pore volume 0.05-1.0cm³ 3 / g; preferably, the BET specific surface area of ​​the catalyst is 25-100m². 2 / g, average pore size 5-25nm, pore volume 0.1-1.0cm³ 3 / g.

[0029] A second aspect of this disclosure provides a method for preparing a catalyst as described in the first aspect of this disclosure, comprising the following steps: S1. Mix the carrier raw material with water to obtain a carrier suspension; mix the active component source, the auxiliary component source with the solvent to obtain a mixed solution; S2. The mixed solution, the first alkaline precipitant, and the carrier suspension are mixed to carry out a first precipitation reaction and a first aging treatment to obtain a solid product; S3. The solid product is subjected to a first washing treatment, a first filtration treatment, a first drying treatment, and a first calcination treatment.

[0030] This disclosure provides a method for preparing a catalyst, wherein a carrier suspension is subjected to a precipitation reaction with a mixed solution containing an active component source and an auxiliary component source in the presence of an alkaline precipitant. This reaction enables a strong interaction between the active metal and the carrier, which is beneficial to improving the catalyst stability. At the same time, it can improve the dispersion of the active component on the carrier surface, thereby improving the catalyst activity. Furthermore, using a carrier suspension is also beneficial to preparing a catalyst with a more uniform particle size distribution, which can avoid particle aggregation and improve catalyst stability.

[0031] In one embodiment, in step S1, the molar ratio of the support raw material: active component source: auxiliary component source: first alkaline precipitant is 1:0.25-4.0:0.12-2.0:1.5-12, preferably 1:0.25-3.0:0.12-1.5:1.5-10; wherein the support raw material is calculated as TiO2. Catalyst preparation according to the raw material ratio in this embodiment can yield a catalyst with high catalytic activity and good stability; preparation according to the preferred raw material molar ratio in this embodiment can further improve the performance of the obtained catalyst.

[0032] In one specific embodiment, the molar ratio of the carrier raw material to water is 1:3.0-9.0, preferably 1:4.0-9.0; the total concentration of the active component source and the auxiliary component source is 0.2-4.0 mol / L, preferably 0.5-3 mol / L. Preparing the catalyst according to the raw material ratio provided in this embodiment is beneficial for obtaining catalysts with better catalytic activity and catalytic stability.

[0033] In one specific embodiment, in step S1, the active component source is selected from one or more of cobalt chloride, cobalt nitrate, cobalt acetate, cobalt carbonate, and cobalt sulfate; preferably, the active component source is selected from one or more of cobalt nitrate, cobalt chloride, and cobalt acetate. The auxiliary agent component source is selected from one or more water-soluble salts of auxiliary metal elements; preferably, the auxiliary agent component source is selected from one or more of ferric nitrate, ferric chloride, manganese nitrate, manganese acetate, cerium nitrate, cerium acetate, ammonium metavanadate, lanthanum nitrate, zirconium oxynitrate, zirconium nitrate, zirconium oxychloride, sodium chloride, sodium nitrate, and potassium nitrate; preferably, the auxiliary agent component source is selected from one or more of ferric nitrate, ferric chloride, manganese nitrate, manganese acetate, cerium nitrate, cerium acetate, sodium chloride, sodium nitrate, and potassium nitrate. The solvent is selected from one or more of water and alcohols; the alcohols include one or more of ethanol and ethylene glycol. The first alkaline precipitant is selected from one or more of ammonia, ammonium carbonate, urea and ammonium bicarbonate; optionally, the first alkaline precipitant is used in the form of an aqueous solution with a concentration of 0.5-3 mol / L.

[0034] In this embodiment, all reagents used can be purchased through ordinary commercial channels or prepared by known methods.

[0035] In one embodiment, in step S2, the conditions for the first precipitation reaction include: a reaction temperature of 20-80℃, preferably 20-60℃; a reaction time of 2-12h, preferably 2-8h; and a pH value of 6.0-10.0, preferably 7.5-10.0. The conditions for the first aging treatment include: an aging temperature of 20-100℃, preferably 30-80℃; and an aging time of 2-48h, preferably 6-24h. Performing the first precipitation reaction and the first aging treatment according to the process conditions in this embodiment is beneficial for improving the reaction performance of the obtained catalyst.

[0036] In a preferred embodiment, the support material is prepared by a method including the following steps: contacting a solution containing a titanium precursor with a second alkaline precipitant to perform a second precipitation reaction and a second aging treatment; subjecting the precipitate to a second washing treatment, a second drying treatment, and a second calcination treatment; the TiO2 support material prepared by the method provided in this embodiment has the characteristics of large specific surface area and relatively concentrated pore size distribution, which helps to prepare a catalyst with high activity and high selectivity for the target product.

[0037] In a preferred embodiment, the molar ratio of the titanium precursor to the second alkaline precipitant is 1:0.5-3.0, preferably 1:1.0-3.0; optionally, in the solution containing the titanium precursor, the molar ratio of the titanium precursor to water is 1:15-100; optionally, in the solution containing the titanium precursor, the concentration of the titanium precursor is 0.05-3.0 mol / L, preferably 0.05-2.0 mol / L. The TiO2 support prepared according to the raw material ratio in this embodiment has a larger specific surface area and a more concentrated pore size distribution.

[0038] In one specific embodiment, the conditions for the second precipitation reaction include: a reaction temperature of 20-100℃, preferably 20-60℃; a reaction time of 2-24h, preferably 2-8h; and a pH value of 5.0-10.0, preferably 6.5-9.0. Preferably, the conditions for the second aging treatment include: an aging temperature of 20-100℃, preferably 30-80℃; and an aging time of 2-24h, preferably 4-12h. Preferably, the conditions for the second drying treatment include: a drying temperature of 80-150℃, more preferably 100-120℃, and a drying time of 2-24h, more preferably 2-12h; Preferably, the conditions for the second calcination treatment include: a calcination temperature of 300-700℃, preferably 400-600℃; a calcination time of 2-24h, preferably 4-12h; and a calcination atmosphere of air. The TiO2 support raw material prepared according to the conditions in this embodiment, especially according to the preferred conditions, has the characteristics of large specific surface area and relatively concentrated pore size distribution, and the prepared catalyst has high activity and high selectivity for the target product.

[0039] In one specific embodiment, the titanium precursor is selected from one or more of titanium tetrachloride, tetrabutyl titanate, and titanium oxysulfate; The second alkaline precipitant is selected from one or more of ammonia, ammonium carbonate, ammonium bicarbonate and urea. Preferably, the concentration of the second alkaline precipitant is 0.5-3 mol / L.

[0040] In one specific embodiment, the specific surface area of ​​the carrier material is 20-100 m². 2 / g, preferably 30-100m 2 / g, with a pore size of 5-35nm, preferably 10-35nm; optionally, the TiO2 support raw material includes rutile phase and anatase phase; based on the total weight of the TiO2 support raw material, the content of anatase phase is 50% by weight or more, preferably 65-90% by weight. Using the support raw material with the structural parameters of this embodiment, a catalyst with better catalytic performance can be prepared.

[0041] According to this disclosure, a first alkaline precipitant and a second alkaline precipitant can be added during both the first precipitation reaction and the second precipitation reaction to control the pH value of the reaction system to remain within a stable range, as required for preparation. The amount of the first alkaline precipitant and the second alkaline precipitant added in this disclosure is based on the total amount added initially and supplemented during the reaction.

[0042] This third aspect of the disclosure provides the application of the catalyst as described in the first aspect of the disclosure in the direct production of aviation kerosene from carbon dioxide and hydrogen.

[0043] In one specific embodiment, the reaction for directly producing aviation kerosene from carbon dioxide and hydrogen includes the following steps: The catalyst is activated; the activated catalyst is contacted with carbon dioxide and hydrogen to carry out a catalytic reaction; in this disclosure, the catalyst is activated before the catalytic reaction, and the Co element in the activated catalyst exists in one or more forms of Co, CoO and Co2C (the existence form of the Co element depends on the reducing atmosphere).

[0044] In a preferred embodiment, the activation treatment conditions include: an activation temperature of 200-450℃, an activation time of 2-24h, an activation pressure of 0-2MPa, and an activation atmosphere selected from one or more of CO, CO2, and H2; preferably, the activation temperature is 200-400℃, the activation time is 4-12h, and the activation pressure is 0-1.0MPa. According to the activation treatment conditions in this embodiment, especially the preferred conditions, a better catalyst activation effect can be obtained, thereby improving the catalytic effect of the catalyst.

[0045] In a preferred embodiment, the activation process includes a first stage of activation and a second stage of activation performed sequentially; wherein the temperature of the first stage of activation is higher than the temperature of the second stage of activation. Preferably, the activation conditions for the first stage include: activation temperature of 200-450℃, activation time of 2-24h, activation pressure of 0-2MPa, and activation atmosphere of H2; preferably, activation temperature of 250-450℃, activation time of 4-12h, and activation pressure of 0-1MPa. The conditions for the second stage of activation include: an activation temperature of 200-400℃, an activation time of 2-24h, an activation pressure of 0-2.0MPa, and an activation atmosphere of H2 and CO, with a molar ratio of H2 to CO of 0.5-2.0; preferably, the activation temperature is 200-350℃, the activation time is 4-12h, the activation pressure is 0-1MPa, and the molar ratio of H2 to CO is 0.5-1.5; the staged activation treatment method and activation conditions provided in this embodiment have the effect of improving catalyst activity and controlling the selectivity of the target product.

[0046] In one specific embodiment, the conditions for the catalytic reaction include: a molar ratio of H2 / CO2 of 1-4, preferably 2-3.5; and a feed gas volume hourly space velocity of 1000-10000 h⁻¹. -1 Preferably 1500-8000h -1 The reaction temperature is 200-450℃, and the reaction pressure is 1-5 MPa; preferably, the reaction temperature is 215-400℃, and the reaction pressure is 2-4 MPa. Synthesizing aviation kerosene according to the catalytic reaction conditions in this embodiment can achieve higher feed conversion rate and target product selectivity.

[0047] The present disclosure is further illustrated by the following examples, but the present disclosure is not limited thereto.

[0048] In the following examples and comparative examples, the contents of active components and auxiliary components in the catalysts were obtained by X-ray fluorescence spectroscopy. In the embodiments and comparative examples of this disclosure, the catalyst phases were analyzed by XRD. The characteristic peak at 2θ = 27.43° represents rutile TiO2, and the characteristic peak at 2θ = 25.28° represents anatase TiO2. The content of the two crystal forms was calculated using the integral area of ​​the peaks. The structural characteristic parameters of the catalyst were obtained by BET testing.

[0049] Example 1 51.5g of titanium tetrachloride (titanium precursor) was dissolved in 250g of water. The solution containing the titanium precursor was then added dropwise to a large beaker with 2.0mol / L ammonia water (second alkaline precipitant) for a precipitation reaction (second precipitation reaction). The molar ratio of titanium precursor to the second alkaline precipitant was 1:2.5. The pH of the system was adjusted to 8.0 by adding ammonia water, and the temperature was controlled at 60℃. The system was then aged for 4 hours under these conditions (second aging treatment) to obtain precipitate I. The precipitate was then washed multiple times with deionized water (second washing reaction), dried at 120℃ for 12 hours (second drying treatment), and calcined at 550℃ for 4 hours (second calcination treatment) to obtain TiO2 support (carrier raw material). The TiO2 support was then dispersed in a large beaker with deionized water to obtain a carrier suspension, wherein the molar ratio of carrier raw material to water was 1:6.0. A solution of 52.3g cobalt nitrate (hexahydrate, active component source), 14.8g ferric nitrate (nonahydrate, auxiliary component source), and 2.0g manganese nitrate (auxiliary component source) was dissolved in 200g water (solvent) (the total concentration of the active component source and auxiliary component source was 1.1mol / L), resulting in a mixed solution containing cobalt precursor and manganese precursor. This mixed solution was then added dropwise with a 2.0mol / L ammonia solution (first alkaline precipitant) in parallel to the large beaker containing the carrier suspension from step (1) to carry out a precipitation reaction (first precipitation reaction). The pH value was adjusted to 8.5 by adding ammonia solution, and the temperature was controlled at 60℃ (first precipitation reaction). The molar ratio of the carrier raw material, active component source, auxiliary component source, and first alkaline precipitant was 1:0.66:0.17:2.10. Then, the mixture was aged for 4 hours under these conditions (first aging reaction). The precipitate was then washed multiple times with deionized water (first washing reaction), filtered (first filtration treatment), dried at 120℃ for 12 hours (first drying treatment), and then calcined at 500℃ for 3 hours (first calcination treatment) to prepare the catalyst.

[0050] The XRD pattern of the catalyst product prepared in this embodiment is shown in the figure below. Figure 1 As shown, by Figure 1 It can be seen that the TiO2 support of the catalyst contains anatase and rutile phases, and the content of the anatase phase calculated by curve integration is 75.4% by weight.

[0051] Comparative Example 1 This comparative example follows the preparation method in Example 1, except that no auxiliary component source is added, while the rest of the process is the same as in Example 1, and a catalyst is prepared.

[0052] Comparative Example 2 This comparative example follows the preparation method described in Example 1, but differs from Example 1 in that: When loading cobalt precursors and auxiliary iron and manganese precursors onto a support, a precipitation process is not used; instead, a conventional impregnation loading treatment is employed, specifically including: A mixed solution containing cobalt precursor and manganese precursor was contacted with 20g of support (solid) and subjected to static impregnation loading at a temperature of 35°C for 8 hours. Then, a first aging reaction, a first washing reaction, a first filtration treatment, a first drying treatment, and a first calcination treatment were carried out (under the same conditions as in Example 1) to prepare the catalyst.

[0053] Example 2 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: The molar ratio of support: active component source: auxiliary component source: first alkaline precipitant was adjusted to 1:3.23:0.68:9.81, and the rest of the process was the same as in Example 1, to prepare the catalyst.

[0054] Example 3 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: The molar ratio of support: active component source: auxiliary component source: first alkaline precipitant was adjusted to 1:0.21:0.36:1.44, and the rest of the process was the same as in Example 1, to prepare the catalyst.

[0055] Example 4 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: The auxiliary component source was replaced with 8.9g of cerium nitrate (hexahydrate, auxiliary component source) and 2.0g of manganese nitrate (auxiliary component source), wherein the molar ratio of support raw material: active component source: auxiliary component source: first alkaline precipitant was 1:0.66:0.12:2.10; the rest of the process was the same as in Example 1, and the catalyst was prepared.

[0056] Example 5 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: The conditions for the first precipitation reaction included: a reaction temperature of 80℃; a reaction time of 12 hours; and a pH of 6.0 for the precipitation system. The conditions for the first aging treatment included an aging temperature of 100°C and an aging time of 2 hours. The remaining processes were the same as in Example 1, and the catalyst was prepared.

[0057] Example 6 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: The conditions for the first precipitation reaction included: a reaction temperature of 90℃; a reaction time of 24 hours; and a pH of 5.0 for the precipitation system. The conditions for the first aging treatment included an aging temperature of 120°C and an aging time of 1 hour. The remaining processes were the same as in Example 1, and the catalyst was prepared.

[0058] Example 7 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: In the step of preparing the support raw material, the concentration of the titanium precursor was 3.0 mol / L; the rest of the process was the same as in Example 1, and the catalyst was prepared.

[0059] Example 8 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: In the step of preparing the carrier raw material The conditions for the second precipitation reaction included: a reaction temperature of 80℃; a reaction time of 12 hours; and a pH of 5.0 for the precipitation system. The conditions for the second aging treatment include: an aging temperature of 100℃ and an aging time of 2 hours. The conditions for the second calcination treatment included: a calcination temperature of 700°C; a calcination time of 2 hours; and a calcination atmosphere of air. The remaining processes were the same as in Example 1, and the catalyst was prepared.

[0060] Example 9 This embodiment refers to the preparation method in Example 1, but differs from Example 1 in that: A carrier suspension was prepared using commercially available TiO2 support material (purchased from Aladdin, with anatase phase content of 30% by weight) and the remaining process was the same as in Example 1 to obtain the catalyst.

[0061] The XRD pattern of the catalyst product prepared in this embodiment is shown in the figure below. Figure 1 As shown, by Figure 1 It can be seen that the TiO2 support of the catalyst contains anatase and rutile phases, and the content of the anatase phase calculated by curve integration is 30.2% by weight.

[0062] The structural characteristics and component content of the catalysts prepared in the above examples and comparative examples are listed in Table 1 below.

[0063] Table 1

[0064] Test Example 1 This test example is used to illustrate the catalytic performance of the catalysts obtained in the above examples and comparative examples in the direct production of aviation kerosene from carbon dioxide and hydrogen.

[0065] The catalysts prepared in the above examples and comparative examples were first activated. The activation conditions included: treatment at 300°C and 0MPa for 6 hours under H2 atmosphere (first activation treatment); and then treatment at 230°C and 0MPa for 4 hours under H2 / CO=0.5 atmosphere (second activation treatment) to obtain the activated catalyst. In the activated catalyst, the Co element exists in the form of Co, CoO and Co2C.

[0066] Then, the reaction gas was switched to reactant gas, and the activated catalyst was brought into contact with carbon dioxide and hydrogen to carry out a catalytic reaction. The conditions for the catalytic reaction included: an H2 / CO2 molar ratio of 3.0 and a feed gas volume hourly space velocity of 5000 h⁻¹.-1 The reaction temperature is 220℃ and the reaction pressure is 3MPa.

[0067] The products of the catalytic reaction after 2 h and 102 h were subjected to chromatographic analysis. Conventional calculation methods in the art were used to obtain the CO2 conversion (%), CO selectivity (%), C1-C7 selectivity (%), and C2-C7 selectivity after 2 h and 102 h of reaction. 8+ Selectivity (%).

[0068] The results of the catalyst performance evaluation are listed in Table 2 below.

[0069] Test Example 2 This test example uses the catalyst prepared in Example 1 and evaluates its performance according to the process conditions in Test Example 1; the difference from Test Example 1 is: For the catalyst activation treatment, only one activation stage was performed: treatment at 400℃ and 0MPa for 12 hours under H2 atmosphere. The rest of the process was the same as in Test Example 1. The catalyst performance evaluation results are listed in Table 2 below.

[0070] Test Example 3 This test example uses the catalyst prepared in Example 1 and evaluates its performance according to the process conditions in Test Example 1; the difference from Test Example 1 is: The conditions for the catalytic reaction include: a molar ratio of H2 / CO2 of 4; and a volume hourly space velocity (VHSV) of 10,000 h⁻¹ for the feed gas. -1 The reaction temperature was 200℃ and the reaction pressure was 1MPa. The rest of the process was the same as in Test Example 1. The catalyst performance evaluation results are listed in Table 2 below.

[0071] Table 2

[0072] In Table 2, C 8+ Selective reduction rate = (C2h) 8+ Selective -102h C 8+ Selective) / (102h-2h).

[0073] Based on the data in Table 2 above, it can be seen that in Test Example 1: The catalyst provided in Comparative Example 1 contains only the active component Co without any auxiliary components. This catalyst is used in the direct production of aviation kerosene from carbon dioxide and hydrogen. The CO2 conversion and target product C at 2 h and 102 h of reaction are compared. 8+ The selectivity is low, while the selectivity for byproducts CO and C1-C7 is high, and under long-term reaction conditions, C 8+The selectivity reduction rate is relatively high; and the catalysts prepared in Examples 1-9 of this disclosure simultaneously possess both active and auxiliary components, which can exert a synergistic effect, enabling them to simultaneously achieve high CO2 conversion and target product C in the direct production of aviation kerosene from carbon dioxide and hydrogen. 8+ Selectivity, as well as lower CO selectivity and C1-C7 selectivity, and under long-term reaction conditions, C 8+ The lower selectivity reduction rate indicates that the catalyst provided in this disclosure has better catalytic activity and catalytic stability; In Comparative Example 2, the active component and auxiliary component were loaded onto the support material using a conventional impregnation method. Comparative Example 2 was compared with Example 1. Under the same conditions of active component content, auxiliary component content, and support properties, Example 1 introduced the active component and auxiliary component onto the support using the precipitation method provided in this disclosure. The catalyst prepared in Example 1 exhibited a higher CO2 conversion rate and a higher target product C in the direct production of aviation kerosene from carbon dioxide and hydrogen. 8+ Under selective and long-term reaction conditions, C 8+ The selectivity reduction rate is lower; Comparing Examples 1, 7-8, and Example 9, it can be seen that Example 9 uses commercially available TiO2 support raw materials; while Examples 1 and 7-8 use precipitation method to prepare TiO2 support raw materials under the same preparation conditions. The anatase phase content in the TiO2 support of the catalysts obtained in Examples 1 and 7-8 is more than 50% by weight. The catalyst products prepared in Examples 1 and 7-8 have better catalytic activity and catalytic stability in the direct production of aviation kerosene from carbon dioxide and hydrogen. Comparing Example 7 with Example 1, it can be seen that the preferred concentration of titanium precursor was used in the preparation of the support raw material in Example 1. Comparing Example 8 with Example 1, it can be seen that the reaction conditions for the second precipitation reaction, the second aging treatment, and the second calcination reaction in the preparation process of the support raw material in Example 1 are within the preferred range of this disclosure. Compared with the catalysts obtained in Examples 7-8, the catalyst obtained in Example 1 has higher CO2 conversion rate and target product C at 2 h and 102 h in the direct production of aviation kerosene from carbon dioxide and hydrogen. 8+ Higher selectivity, lower selectivity for byproducts, and C 8+ The selectivity reduction rate is lower; Comparing Example 5 and Example 6, it can be seen that in Example 5, the first precipitation reaction and the first aging reaction were carried out according to the optimized conditions provided in this disclosure. The CO2 conversion rate and the target product C of the catalyst obtained in Example 5 after 2 hours and 102 hours of reaction were significantly higher. 8+ Higher selectivity, lower selectivity for byproducts, and C 8+The selectivity reduction rate is lower; further comparison of Example 5 with Example 1 shows that the conditions of the first precipitation reaction and the first aging reaction in Example 1 are within the further preferred range provided in this disclosure, and the catalyst obtained in Example 1 has higher catalytic activity and better catalytic stability. Comparing Example 2 with Example 3, it can be seen that the component content of the catalyst in Example 2 is within the preferred range provided in this disclosure, and the catalyst obtained in Example 2 has higher catalytic activity and better catalytic stability; further comparing Example 2 with Example 1, the component content of the catalyst in Example 1 is within the further preferred range provided in this disclosure, and the catalyst obtained in Example 1 has higher catalytic activity and better catalytic stability.

[0074] Comparing Test Example 1 and Test Example 2, it can be seen that under the same catalyst conditions, Test Example 1 involves two-stage activation treatment of the catalyst, while Test Example 2 involves only one-stage activation treatment. The catalyst in Test Example 1 has higher catalytic activity and better catalytic stability. Comparing Test Example 1 and Test Example 3, it can be seen that under the same catalyst conditions, the catalyst in Test Example 1, which was carried out according to the preferred reaction conditions provided in this disclosure, has higher catalytic activity and better catalytic stability.

[0075] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0076] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0077] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A catalyst for the direct production of aviation kerosene from carbon dioxide and hydrogen, characterized in that, Based on the total weight of the catalyst, the catalyst comprises: 10-50% by weight of active component, 0.05-15% by weight of auxiliary component and balance of support; wherein, the active component includes Co element; the auxiliary component is selected from one or more transition metal elements and alkali metal elements; the support comprises TiO2; wherein the contents of the active component and auxiliary component are in the form of metal oxides.

2. The catalyst according to claim 1, characterized in that, Based on the total weight of the catalyst, the catalyst comprises: 10-40% by weight of active component, 0.05-10% by weight of auxiliary component and balance of support; preferably, the catalyst comprises: 10-40% by weight of active component, 0.05-8% by weight of auxiliary component and balance of support. Preferably, the auxiliary component is selected from one or more of iron, manganese, cerium, vanadium, lanthanum, zirconium, sodium, and potassium; more preferably, it is selected from one or more of iron, manganese, cerium, sodium, and potassium.

3. The catalyst according to claim 1, characterized in that, The TiO2 in the carrier includes rutile phase and anatase phase; based on the total weight of the TiO2, the content of the anatase phase is more than 50% by weight, preferably 65-90% by weight.

4. The catalyst according to claim 1, characterized in that, The catalyst has a BET specific surface area of ​​20-100 m². 2 / g, average pore size 5-30nm, pore volume 0.05-1.0cm³ 3 / g; preferably, the BET specific surface area of ​​the catalyst is 25-100m². 2 / g, average pore size 5-25nm, pore volume 0.1-1.0cm³ 3 / g.

5. A method for preparing the catalyst according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Mix the carrier raw materials with water to obtain a carrier suspension; The active ingredient source, the auxiliary ingredient source, and the solvent are mixed to obtain a mixed solution; S2. The mixed solution, the first alkaline precipitant, and the carrier suspension are mixed to carry out a first precipitation reaction and a first aging treatment to obtain a solid product; S3. The solid product is subjected to a first drying treatment and a first calcination treatment.

6. The method according to claim 5, characterized in that, The molar ratio of the carrier raw material, active component source, auxiliary component source, and first alkaline precipitant is 1:0.25-4.0:0.12-2.0:1.5-12, preferably 1:0.25-3.0:0.12-1.5:1.5-10; Optionally, the molar ratio of the carrier material to water is 1:3.0-9.0, preferably 1:4.0-9.0; Optionally, the total concentration of the active component source and the auxiliary component source in the mixed solution is 0.2-4.0 mol / L, preferably 0.5-3 mol / L.

7. The method according to claim 5, characterized in that, In step S1, the active component source is selected from one or more of cobalt chloride, cobalt nitrate, cobalt acetate, cobalt carbonate, and cobalt sulfate; preferably, the active component source is selected from one or more of cobalt nitrate, cobalt chloride, and cobalt acetate. The auxiliary agent component source is selected from one or more water-soluble salts of auxiliary metal elements; preferably, the auxiliary agent component source is selected from one or more of ferric nitrate, ferric chloride, manganese nitrate, manganese acetate, cerium nitrate, cerium acetate, ammonium metavanadate, lanthanum nitrate, zirconium oxynitrate, zirconium nitrate, zirconium oxychloride, sodium chloride, sodium nitrate, and potassium nitrate; preferably, the auxiliary agent component source is selected from one or more of ferric nitrate, ferric chloride, manganese nitrate, manganese acetate, cerium nitrate, cerium acetate, sodium chloride, sodium nitrate, and potassium nitrate. The solvent is selected from one or more of water and alcohols; the alcohols include one or more of ethanol and ethylene glycol. The first alkaline precipitant is selected from one or more of ammonia, ammonium carbonate, urea and ammonium bicarbonate; optionally, the first alkaline precipitant is used in the form of an aqueous solution with a concentration of 0.5-3 mol / L.

8. The method according to claim 5, characterized in that, In step S2, the conditions for the first precipitation reaction include: a reaction temperature of 20-80℃, preferably 20-60℃; a reaction time of 2-12h, preferably 2-8h; and a pH value of 6.0-10.0, preferably 7.5-10.

0. The conditions for the first aging treatment include: an aging temperature of 20-100℃, preferably 30-80℃; and an aging time of 2-48h, preferably 6-24h.

9. The method according to claim 5, characterized in that, In step S3, the conditions for the first drying treatment include: a drying temperature of 80-150℃, preferably 100-120℃, and a drying time of 2-24h, preferably 2-12h. The conditions for the first calcination treatment include: a calcination temperature of 300-700℃, preferably 350-700℃, a calcination time of 2-24h, preferably 4-12h, and a calcination atmosphere of air.

10. The method according to claim 5, characterized in that, The carrier raw material is prepared by a method comprising the following steps: The solution containing the titanium precursor is contacted with a second alkaline precipitant to carry out a second precipitation reaction and a second aging treatment; the precipitate is then subjected to a second washing treatment, a second drying treatment, and a second calcination treatment. Preferably, the molar ratio of the titanium precursor to the second alkaline precipitant is 1:0.5-3.0, more preferably 1:1.0-3.0; optionally, in the solution containing the titanium precursor, the concentration of the titanium precursor is 0.05-3.0 mol / L, more preferably 0.05-2.0 mol / L. Preferably, the conditions for the second precipitation reaction include: a reaction temperature of 20-100℃, preferably 20-60℃; a reaction time of 2-24h, preferably 2-8h; and a pH value of 5.0-10.0, preferably 6.5-9.

0. Preferably, the conditions for the second aging treatment include: an aging temperature of 20-100℃, preferably 30-80℃; and an aging time of 2-24h, preferably 4-12h. Preferably, the conditions for the second drying treatment include: a drying temperature of 80-150℃, more preferably 100-120℃, and a drying time of 2-24h, more preferably 2-12h; Preferably, the conditions for the second calcination treatment include: a calcination temperature of 300-700℃, preferably 400-600℃; a calcination time of 2-24h, preferably 4-12h; and a calcination atmosphere of air. Optionally, the titanium precursor is selected from one or more of titanium tetrachloride, tetrabutyl titanate, and titanium oxysulfate; The second alkaline precipitant is selected from one or more of ammonia, ammonium carbonate, ammonium bicarbonate and urea. Preferably, the concentration of the second alkaline precipitant is 0.5-3 mol / L.

11. The use of the catalyst according to any one of claims 1-4 in the reaction of directly producing aviation kerosene from carbon dioxide and hydrogen.

12. The application according to claim 11, characterized in that, The reaction for directly producing aviation kerosene from carbon dioxide and hydrogen includes the following steps: The catalyst is activated; the activated catalyst is then contacted with carbon dioxide and hydrogen to carry out a catalytic reaction. Preferably, the activation conditions include: an activation temperature of 200-450℃, an activation time of 2-24h, an activation pressure of 0-2MPa, and an activation atmosphere selected from one or more of CO, CO2, and H2; preferably, the activation temperature is 200-400℃, the activation time is 4-12h, and the activation pressure is 0-1.0MPa; the Co element in the activated catalyst exists in one or more forms selected from Co, CoO, and Co2C. Preferably, the conditions for the catalytic reaction include: a molar ratio of H2 / CO2 of 1-4, preferably 2-3.5; and a volume hourly space velocity (VHSV) of 1000-10000 h⁻¹. -1 Preferably 1500-8000h -1 The reaction temperature is 200-450℃ and the reaction pressure is 1-5MPa; preferably, the reaction temperature is 215-400℃ and the reaction pressure is 2-4MPa.

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