Organic liquid dehydrogenation catalyst, preparation method thereof and organic liquid dehydrogenation method

Abstract

The invention relates to the field of catalytic dehydrogenation of organic liquid, and discloses an organic liquid dehydrogenation catalyst, a preparation method thereof and an organic liquid dehydrogenation method. The organic liquid dehydrogenation catalyst comprises a modified carrier, an active metal component and an auxiliary component, wherein the active metal component and the auxiliary component are loaded on the modified carrier; the auxiliary components comprise Fe and Co; in terms of elements, the mass ratio of Fe to Co in the auxiliary component is 1: (0.7-2.8); the active metal component is at least one of noble metals; the modified carrier comprises aluminum oxide and a modified component, and the modified component comprises at least one of TiO2, SiO2 and MgO; the mass ratio of the modified component to the aluminum oxide is (1-13): 100; in terms of elements, the mass ratio of the auxiliary component to the active metal component is (0.2-2): 1. The organic liquid dehydrogenation catalyst has high dehydrogenation activity and selectivity when used in organic liquid dehydrogenation, side reactions in the dehydrogenation process are effectively reduced, and the obtained product hydrogen is high in purity.

Description

Technical Field

[0001] The present invention relates to the field of catalytic dehydrogenation of organic liquids, and particularly relates to an organic liquid dehydrogenation catalyst, a preparation method thereof, and an organic liquid dehydrogenation method. Background Art

[0002] Hydrogen energy is regarded as an ideal alternative to traditional fossil fuels due to its high energy density, environmental friendliness, and recyclability.

[0003] Among many liquid organic hydrogen carrier (LOHCs) systems, toluene and dibenzyltoluene have been the most studied. However, their dehydrogenation reactions need to be carried out at high temperatures (above 300 °C), resulting in rapid deactivation of the catalyst and excessive energy consumption, which severely restricts industrial applications. In recent years, N-alkylcarbazole materials (such as N-methylcarbazole, N-ethylcarbazole, N-propylcarbazole, N-butylcarbazole, N-isopropylcarbazole, etc.) have become the focus of research. By introducing branched chains such as methyl and ethyl groups on the nitrogen atom, the strong interaction between the nitrogen atom and the dehydrogenation catalyst is weakened, thereby enhancing the catalytic activity and selectivity.

[0004] However, existing organic liquid dehydrogenation catalysts still face severe challenges. During the dehydrogenation process, branched chain groups (such as methyl, ethyl, propyl, butyl, isopropyl, etc.) of N-alkylcarbazole are prone to C-C bond or C-N bond cleavage, and then low-carbon hydrocarbon impurities such as methane, ethane, and propane are mixed into the obtained product gas, resulting in a significant decrease in the purity of hydrogen. Such low-purity hydrogen cannot meet the application requirements of high-end fields such as fuel cells or semiconductor manufacturing. Therefore, it is necessary to add subsequent hydrogen purification processes, which not only increase the investment cost, but also damage the chemical structure of the organic liquid and reduce its cyclic service life. There is currently no mature solution to the above problems. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problem of low activity of existing organic liquid dehydrogenation catalysts, and to provide an organic liquid dehydrogenation catalyst, a preparation method thereof, and an organic liquid dehydrogenation method. The organic liquid dehydrogenation catalyst has high dehydrogenation activity and selectivity in the dehydrogenation of organic liquids, effectively reduces side reactions during the dehydrogenation process, and the product hydrogen has high purity.

[0006] To achieve the above purpose, in the first aspect of the present invention, an organic liquid dehydrogenation catalyst is provided. The catalyst includes a modified carrier and an active metal component and an auxiliary component supported on the modified carrier; the auxiliary component includes Fe and Co; in terms of elements, the mass ratio of Fe to Co in the auxiliary component is 1:0.7 - 2.8;

[0007] The active metal component is at least one of noble metals; the modified carrier includes alumina and a modifying component, and the modifying component includes at least one of TiO2, SiO2, and MgO;

[0008] The mass ratio of the modifying component to the alumina is 1-13:100;

[0009] In terms of elements, the mass ratio of the promoter component to the active metal component is 0.2-2:1.

[0010] The second aspect of the present invention provides a method for preparing an organic liquid dehydrogenation catalyst, comprising the following steps:

[0011] (1) Mixing an alumina precursor and a modifying component precursor, and subjecting the mixture to shaping to obtain a modified carrier; the mass ratio of the modifying component precursor in terms of oxide to the alumina precursor on a dry basis is 1-13:100;

[0012] (2) Loading the active metal component and the promoter component on the modified carrier to obtain a catalyst intermediate; in terms of elements, the mass ratio of the promoter component to the active metal component is 0.2-2:1;

[0013] (3) Calcining and reducing the catalyst intermediate;

[0014] The modifying component precursor includes at least one of a Ti source, an Si source, and an Mg source; the promoter component includes Fe and Co; in terms of elements, the mass ratio of Fe to Co is 1:0.7-2.8; the active metal component is at least one of noble metals.

[0015] The third aspect of the present invention provides an organic liquid dehydrogenation method, in which a hydrogenated organic liquid is contacted with a catalyst, and the catalyst is the organic liquid dehydrogenation catalyst described in the first aspect above or the organic liquid dehydrogenation catalyst prepared by the method described in the second aspect above.

[0016] Through the above technical solutions, the present invention has the following beneficial effects:

[0017] The organic liquid dehydrogenation catalyst provided by the present invention uses alumina containing a modifying component as a modified carrier, and improves the distribution of the active metal component supported on the carrier by doping the specific modifying component into the alumina carrier, and optimizes the particle size of the active metal, thereby improving the reaction activity of the dehydrogenation catalyst; through the synergistic effect of the modified carrier and the noble metal component and the promoter components (Fe and Co) supported on the modified carrier, the electronic state on the surface of the active metal and the adsorption and desorption time of the reactants and products on the surface of the active metal are improved, thereby improving the dehydrogenation activity and selectivity of the dehydrogenation catalyst; further by controlling the doping amount of the modifying component (including at least one of Ti, Si, and Mg) in the modified carrier, introducing the promoter components Fe and Co onto the active metal component (noble metal), and controlling the amounts of the active metal component and the promoter components and the mass ratio of Fe and Co, the utilization rate of the active metal can be improved, and the activity and selectivity of the dehydrogenation catalyst can be further improved.

[0018] By adopting the synergistic effect of the modified carrier, the active metal component and the promoter components (Fe and Co), the present invention solves the problems of low catalyst activity, many side reactions, and low product hydrogen purity in the process of organic liquid dehydrogenation. The organic liquid dehydrogenation catalyst provided by the present invention has high dehydrogenation activity and selectivity when used in the dehydrogenation of organic liquids (especially nitrogen alkyl carbazole materials), effectively reduces side reactions in the dehydrogenation process, and obtains a product with high hydrogen purity. Detailed implementation mode

[0019] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0020] In the first aspect of the present invention, an organic liquid dehydrogenation catalyst is provided. The catalyst includes a modified carrier and an active metal component and a promoter component supported on the modified carrier; the promoter component includes Fe and Co; in terms of elements, the mass ratio of Fe and Co in the promoter component is 1:0.7 - 2.8;

[0021] The active metal component is at least one of noble metals; the modified carrier includes alumina and a modifying component, and the modifying component includes at least one of TiO2, SiO2, and MgO;

[0022] The mass ratio of the modifying component to the alumina is 1 - 13:100;

[0023] In terms of elements, the mass ratio of the promoter component to the active metal component is 0.2 - 2:1.

[0024] In the present invention, the inventors found that by using alumina containing a modifying component as a modified support, and doping a specific modifying component into the alumina support, the distribution of the active metal component supported on the support can be improved, the particle size of the active metal can be optimized, thereby enhancing the reaction activity of the organic liquid dehydrogenation catalyst; through the synergistic effect of the modified support and the noble metal component and the promoter component supported on the modified support, the dehydrogenation activity and selectivity of the organic liquid dehydrogenation catalyst are improved; by controlling the doping amount of the modifying component in the modified support, introducing promoter components Fe and Co onto the active metal component, and controlling the amounts of the active metal component and the promoter component as well as the mass ratio of Fe and Co, the activity and selectivity of the organic liquid dehydrogenation catalyst are further improved, effectively reducing side reactions during the dehydrogenation process, and the product hydrogen has high purity.

[0025] In some embodiments of the present invention, preferably, in terms of elements, the mass ratio of the promoter component to the active metal component is 0.3 - 1.6:1. For example, it can be 0.3:1, 0.5:1, 0.8:1, 1:1, 1.2:1, 1.4:1, 1.6:1, and any value within the range composed of any two of the above values. By using the above-preferred mass ratio of the promoter component to the active metal component, it is beneficial to optimize the synergistic effect between the promoter component and the active metal component, and further improve the activity of the dehydrogenation catalyst.

[0026] In some embodiments of the present invention, preferably, based on the total mass of the modified support, in terms of elements, the content of the active metal component is 0.1 - 1 wt%, and the content of the promoter component is 0.1 - 1 wt%. More preferably, based on the total mass of the modified support, in terms of elements, the content of the active metal component is 0.3 - 0.8 wt%, and the content of the promoter component is 0.15 - 0.8 wt%. In the present invention, on the basis of controlling the mass ratio of the active metal component and the promoter component within the aforementioned range, further controlling the content of the active metal component in terms of elements and the content of the promoter component in terms of elements within the above range is more conducive to exerting the synergistic effect between the promoter component and the active metal component, and further improving the activity and selectivity of the catalyst.

[0027] In some embodiments of the present invention, preferably, the mass ratio of Fe to Co in the promoter component by element is 1:1 - 2.5. For example, it can be 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.4, 1:2.5, and any value within the range composed of any two of the above values. Controlling the mass ratio of Fe to Co in the promoter component within the above range is beneficial to further optimizing the synergistic effect with the active metal component, thereby being more conducive to improving the electronic state on the surface of the active metal, further enhancing the activity and selectivity of the dehydrogenation catalyst, effectively inhibiting side reactions during the dehydrogenation of organic liquids, and improving the purity of the hydrogen product.

[0028] In some embodiments of the present invention, preferably, the mass ratio of the modifying component to the alumina is 2 - 12:100. For example, it can be 2:100, 4:100, 5:100, 6:100, 8:100, 10:100, 12:100, and any value within the range composed of any two of the above values. Using the above-preferred mass ratio of the modifying component to the alumina in terms of oxides is beneficial to further improving the distribution of the active metal component, optimizing the particle size of the active metal, and enhancing the reaction activity of the dehydrogenation catalyst.

[0029] In the present invention, the modifying component is doped into the alumina support. In some embodiments of the present invention, preferably, based on the total mass of the modified support, the content of alumina is 88 - 99 wt%; the content of the modifying component is 1 - 12 wt%. More preferably, based on the total mass of the modified support, the content of alumina is 90 - 98 wt%; the content of the modifying component is 2 - 10 wt%. In the present invention, when the modified support only contains alumina and the modifying component, the total amount of alumina and the modifying component is 100 wt%.

[0030] In the present invention, on the basis of controlling the mass ratio of the modifying component to alumina to meet the aforementioned range, further controlling the contents of alumina and the modifying component in the modified support within the above-preferred range is more conducive to optimizing their distribution on the modified support, improving the utilization rate of the active metal, improving the electronic state on the surface of the active metal, regulating the adsorption and desorption behaviors of reactants and products on the surface of the active metal, and thereby further enhancing the activity of the organic liquid dehydrogenation reaction.

[0031] In the present invention, the types of the noble metals have a relatively wide selection range. Preferably, the noble metal is Pd and / or Pt, and preferably Pd.

[0032] In some embodiments of the present invention, preferably, the modifying component is TiO2. By using the above-preferred modifying component, it is more conducive to improving the stepwise distribution of the active metal and further enhancing the activity and selectivity of the dehydrogenation catalyst.

[0033] In some particularly preferred embodiments of the present invention, the active metal component is Pd and the modifying component is TiO2. By using the above-preferred embodiments, the dehydrogenation catalyst has higher dehydrogenation activity and the purity of the hydrogen product is higher.

[0034] The second aspect of the present invention provides a method for preparing an organic liquid dehydrogenation catalyst, comprising the following steps:

[0035] (1) Mix an alumina precursor and a modifying component precursor, and form them into a modified support; the mass ratio of the modifying component precursor in terms of oxide and the alumina precursor on a dry basis is 1-13:100;

[0036] (2) Load an active metal component and an auxiliary component on the modified support to obtain a catalyst intermediate; in terms of elements, the mass ratio of the auxiliary component to the active metal component is 0.2-2:1;

[0037] (3) Calcinate and reduce the catalyst intermediate;

[0038] The modifying component precursor includes at least one of a Ti source, an Si source, and an Mg source; the auxiliary component includes Fe and Co; in terms of elements, the mass ratio of Fe to Co is 1:0.7-2.8; the active metal component is at least one of noble metals.

[0039] In the present invention, the inventors found during the research process that by doping the specific type of modifying component precursor into the alumina support, the distribution of the active metal component can be improved, the particle size of the active metal can be optimized, and the reaction activity of the organic liquid dehydrogenation catalyst can be enhanced; further, by loading the active metal component and the auxiliary metal component on the modified support, the synergistic effect of the modified support with the active metal component (noble metal component) and the auxiliary component (Fe, Co) can improve the electronic state on the surface of the active metal and the adsorption and desorption time of the reactants and products on the surface of the active metal, thereby enhancing the activity and selectivity of the dehydrogenation catalyst; by controlling the doping amount of the modifying component in the modified support, introducing the auxiliary component to the active metal component, and controlling the amounts of the active metal component and the auxiliary component as well as the mass ratio of Fe to Co, the utilization rate of the active metal can be increased, the reaction activity and selectivity of the organic liquid dehydrogenation catalyst can be enhanced, side reactions during the organic liquid dehydrogenation process can be effectively reduced, and the purity of the product hydrogen is high.

[0040] In the present invention, the alumina precursor is any substance that can be converted into alumina by calcination, which is well-known to those skilled in the art. Preferably, the alumina precursor is pseudo-boehmite.

[0041] In the present invention, the selection range of the Ti source is relatively wide, and any conventional substance in the art that can provide Ti element can be applied to the present invention. For example, it can be TiO2 or any substance that can be converted into TiO2 by calcination. Preferably, the Ti source is selected from at least one of TiO2, TiCl4, and tetrabutyl titanate.

[0042] In the present invention, there is no particular limitation on the selection of the Si source. Preferably, the Si source is selected from SiO2 and / or silica sol.

[0043] In the present invention, there is no particular limitation on the selection of the Mg source, which can be magnesium oxide or any substance that can be converted into magnesium oxide by calcination. Preferably, the magnesium source is selected from at least one of magnesium oxide, magnesium nitrate, magnesium acetate, and basic magnesium carbonate.

[0044] In some embodiments of the present invention, preferably, the modifying component precursor includes a Ti source.

[0045] In some embodiments of the present invention, preferably, in step (1), the mass ratio of the modifying component precursor calculated as oxides to the alumina precursor on a dry basis is 2-12:100. Using the above preferred mass ratio is beneficial to improving the activity of the dehydrogenation catalyst.

[0046] In some embodiments of the present invention, preferably, the amounts of the alumina precursor and the modifying component precursor are such that, based on the total mass of the modified support, the content of alumina is 88-99 wt%; the content of the modifying component is 1-12 wt%. More preferably, the amounts of the alumina precursor and the modifying component precursor are such that, based on the total mass of the modified support, the content of alumina is 90-98 wt%; the content of the modifying component is 2-10 wt%. In the present invention, when the modified support only contains alumina and the modifying component, the contents of alumina and the modifying component are 100 wt%. In the present invention, on the basis of controlling the mass ratio of the modifying component precursor and the alumina precursor to meet the foregoing range, further controlling the contents of alumina and the modifying component in the modified support within the above preferred range is more conducive to adopting the above preferred composition of the modified support, further improving the activity of the dehydrogenation catalyst, and reducing unnecessary side reactions.

[0047] In the present invention, there is no particular limitation on the molding method in step (1), and conventional methods in the art can be used for molding. For example, it can be extrusion molding. Preferably, the method in step (1) further includes: optionally adding an extrusion aid and a peptizing agent during the molding process.

[0048] In the present invention, there is no particular limitation on the type of the extrusion aid, and conventional selections in the art can be adopted. Preferably, the extrusion aid is sesbania powder. The present invention has a wide selection range for the dosage of the extrusion aid. Preferably, based on the dry basis mass of the alumina precursor, the dosage of the extrusion aid is 2-5 wt%.

[0049] In the present invention, there is no particular limitation on the type of the peptizing agent, and conventional selections in the art can be adopted. Preferably, the peptizing agent is an inorganic acid. The inorganic acid in the present invention is preferably nitric acid. The present invention has a wide selection range for the dosage of the peptizing agent. Preferably, based on the dry basis mass of the alumina precursor, the dosage of the peptizing agent is 0.2-1.5 wt%.

[0050] In some embodiments of the present invention, preferably, step (1) further includes: drying and calcining the molded product.

[0051] In the present invention, there is no particular limitation on the method and conditions of the drying, and conventional methods in the art can be used to dry the molded product. Preferably, the drying temperature is 100-150 °C, and the drying time is 2-5 h.

[0052] In some embodiments of the present invention, preferably, the calcining temperature is 500-1000 °C, preferably 600-900 °C. For example, it can be 600 °C, 650 °C, 700 °C, 750 °C, 800 °C, 850 °C, 900 °C, and any value within the range composed of any two of the above values. Using the above preferred calcining temperature is beneficial to promoting the molding and stability of the modified support, optimizing the active metal distribution, further increasing the surface area of the active metal and the catalytic active sites, and improving the activity of the dehydrogenation catalyst.

[0053] In the present invention, there is a wide selection range for other conditions of the calcining, and conventional calcining conditions in the art can be adopted as long as the calcining temperature meets the above range. Preferably, the conditions of the calcining further include: the heating rate is 1-5 °C / min, preferably 2-3 °C / min; the time is 1-6 h, preferably 2-4 h.

[0054] In the present invention, in step (2), there is no particular limitation on the loading method, and the conventional active component loading methods in the art can be adopted. For example, the active metal component and the promoter component can be simultaneously loaded onto the modified carrier in one step, or can be carried out step by step, and there is no particular limitation in the present invention.

[0055] In some embodiments of the present invention, preferably, the loading method in step (2) includes: impregnating the modified carrier with an impregnating solution containing a precursor of the active metal component and a precursor of the promoter component, and then drying.

[0056] In the present invention, there is no particular limitation on the concentration of the impregnating solution, as long as the target loading amount is satisfied. There is also no particular limitation on the specific operating conditions of the impregnation in the present invention, and it is also based on satisfying the target component loading amount. Preferably, the temperature of the impregnation is 20 - 40 °C, and the time is 1 - 3 h.

[0057] In the present invention, in step (2), there is no particular limitation on the drying method and conditions, and the products obtained by shaping can be dried by conventional methods in the art. Preferably, the drying temperature is 100 - 150 °C, and the drying time is 2 - 5 h.

[0058] In some embodiments of the present invention, preferably, in step (2), based on elements, the mass ratio of the promoter component to the active metal component is 0.3 - 1.6:1.

[0059] In some embodiments of the present invention, preferably, based on elements, the mass ratio of Fe to Co is 1:1 - 2.5. Controlling the mass ratio of Fe to Co within the above range is beneficial to further improving the activity and selectivity of the dehydrogenation catalyst, effectively suppressing side reactions during dehydrogenation, and improving the purity of hydrogen products.

[0060] In the present invention, preferably, the promoter component precursor includes an Fe source and a Co source. The Fe source and the Co source in the present invention are each independently selected from soluble compounds of Fe and Co. The types of the soluble compounds in the present invention have a wide selection range and can be various conventional soluble inorganic salts in the art. Preferably, the promoter component precursors are each independently selected from at least one of nitrates, chlorides, and organic salts of Fe and Co. The above inorganic salts may also contain crystal water, which is well known to those skilled in the art.

[0061] In some embodiments of the present invention, preferably, the active metal component is Pd and / or Pt, preferably Pd.

[0062] In the present invention, preferably, the precursor of the active metal component is a soluble compound containing the noble metal. The types of the soluble compounds in the present invention have a wide selection range and can be various conventional soluble inorganic salts in the art. Preferably, the precursor of the active metal component is at least one of nitrates, chlorides and organic salts containing the noble metal. The above-mentioned inorganic salts may also contain crystal water, which is well known to those skilled in the art.

[0063] In some embodiments of the present invention, preferably, the amounts of the impregnating solution and the modified carrier are such that, based on the total mass of the modified carrier, calculated by element, the content of the active metal component is 0.1-1 wt%, preferably 0.3-0.8 wt%, and the content of the promoter component is 0.1-1 wt%, preferably 0.15-0.8 wt%. In the present invention, further controlling the contents of the active metal component and the promoter component calculated by element within the above ranges is more conducive to exerting the synergistic effect between the promoter component and the active metal component, and further improving the activity and selectivity of the catalyst.

[0064] In the present invention, in step (3), the catalyst intermediate is calcined. The conditions of the calcination have a wide selection range. Preferably, the conditions of the calcination in step (3) include: the temperature is 350-600 °C, preferably 400-550 °C; the time is 2-6 h, preferably 3-5 h. Adopting the above preferred calcination conditions is more conducive to optimizing the distribution of the active components and further improving the activity of the dehydrogenation catalyst.

[0065] In the present invention, in step (3), the calcined product is reduced. Through the reduction, the precursor of the active metal component and the precursor of the promoter component are fixed on the surface of the catalyst modified carrier in a reduced state, and the precursor of the modifying component is doped in the modified carrier in an oxidized state to obtain the dehydrogenation reaction catalyst. In the present invention, preferably, the reduction in step (3) is carried out in the presence of a reducing atmosphere, preferably in the presence of hydrogen. The present invention does not particularly limit the specific conditions of the reduction, as long as at least part of the active metal can be reduced, which is well known to those skilled in the art. Preferably, the reduction temperature is 200-400 °C, preferably 250-350 °C; the reduction time is 2-8 h, preferably 3-6 h.

[0066] The third aspect of the present invention provides a method for dehydrogenating an organic liquid, in which the hydrogenated organic liquid is contacted with a catalyst, and the catalyst is the organic liquid dehydrogenation catalyst described in the first aspect above or the organic liquid dehydrogenation catalyst prepared by the method described in the second aspect above.

[0067] In the present invention, the "hydrogenated organic liquid" refers to the hydrogenation product of an organic liquid material, which can be a partial hydrogenation product or a full hydrogenation product.

[0068] In the present invention, the "organic liquid" refers to an organic liquid hydrogen storage material.

[0069] In the present invention, the selection range of the specific type of the organic liquid is relatively wide, and any known substance in the art that can achieve hydrogenation and dehydrogenation can be applied to the present invention. Preferably, the organic liquid is a nitrogen-containing heterocyclic material, preferably a nitrogen-alkylcarbazole material, more preferably selected from at least one of N-methylcarbazole, N-ethylcarbazole, N-propylcarbazole, N-butylcarbazole, and N-isopropylcarbazole, and further preferably N-methylcarbazole.

[0070] In some embodiments of the present invention, preferably, the conditions for the contact include: the reaction pressure is 0.07 - 0.13 MPa, preferably 0.08 - 0.11 MPa; the reaction temperature is 170 - 240 °C, preferably 180 - 230 °C; the volume space velocity is 0.2 - 1.5 h -1 , preferably 0.3 - 1 h -1 . In the present invention, unless otherwise specified, the pressure used refers to the gauge pressure.

[0071] The present invention will be described in detail below through examples. In the present invention, unless otherwise specified, room temperature refers to 25 ± 5 °C.

[0072] In the following examples and comparative examples, unless otherwise specified, the raw materials used are all commercially available.

[0073] Example 1

[0074] (1) Preparation of modified carrier: Weigh 340 g of pseudo-boehmite (dry basis content is 70 wt%), 12 g of TiO2, and 7.5 g of sesbania powder as raw material powders, and put the raw material powders into a kneader and mix evenly; Weigh 1.92 g of nitric acid (concentration is 65 wt%) and dissolve it in a certain amount of deionized water to prepare a dilute acid solution; Add the above dilute nitric acid solution to the evenly mixed raw material powders, and continue to knead for 25 min; Then extrude the kneaded sample, and then dry it in an oven at 100 °C for 4 h, and then transfer the dried sample to a muffle furnace and heat it to 800 °C at a heating rate of 3 °C / min and calcine it for 4 h to obtain a modified carrier C1 with a TiO2 content of 4.8 wt%.

[0075] (2) Weigh 1.72 g of palladium nitrate (palladium content is 17.43 wt%) and 0.362 g of Fe(NO3)3·9H2O and 0.494 g of Co(NO3)2·6H2O, dissolve them in a certain amount of dilute ammonia water solution (concentration is 3 wt%) to form an impregnation solution; put the impregnation solution and 50 g of the modified carrier prepared in step (1) into a rotary evaporation container, impregnate for 2 h at room temperature, then dry at 120 °C for 2 h, then transfer the sample to a muffle furnace and calcine at 450 °C for 4 h, and finally transfer the sample to a tubular furnace and reduce it under hydrogen at 350 °C for 3 h. After cooling, the organic liquid dehydrogenation catalyst S1 is obtained (the component contents are shown in Table 1).

[0076] Example 2

[0077] Perform step (1) according to the method described in Example 1;

[0078] In step (2), the mass of Fe(NO3)3·9H2O is 0.543 g, and the mass of Co(NO3)2·6H2O is 0.864 g; the organic liquid dehydrogenation catalyst S2 is obtained (the component contents are shown in Table 1).

[0079] Example 3

[0080] Perform step (1) according to the method described in Example 1;

[0081] In step (2), the mass of palladium nitrate (palladium content is 17.43 wt%) is 1.15 g; the organic liquid dehydrogenation catalyst S3 is obtained (the component contents are shown in Table 1).

[0082] Example 4

[0083] Perform step (1) according to the method described in Example 1;

[0084] In step (2), the mass of palladium nitrate (palladium content is 17.43 wt%) is 1.15 g, the mass of Fe(NO3)3·9H2O is 0.181 g, and the mass of Co(NO3)2·6H2O is 0.247 g; the organic liquid dehydrogenation catalyst S4 is obtained (the component contents are shown in Table 1).

[0085] Example 5

[0086] Perform step (1) according to the method described in Example 1;

[0087] In step (2), the mass of Fe(NO3)3·9H2O is 1.086 g, and the mass of Co(NO3)2·6H2O is 1.235 g; the organic liquid dehydrogenation catalyst S5 is obtained (the component contents are shown in Table 1).

[0088] Example 6

[0089] Perform step (1) according to the method described in Example 1;

[0090] In step (2), the mass of Fe(NO3)3·9H2O is 1.448 g, and the mass of Co(NO3)2·6H2O is 1.482 g; obtain the organic liquid dehydrogenation catalyst S6 (the component contents are shown in Table 1).

[0091] Example 7

[0092] According to the method described in Example 1, the difference is that

[0093] In step (1), the mass of pseudo-boehmite (dry basis content is 70 wt%) is 331.4 g, and the mass of TiO2 is 18 g; prepare the modified carrier C2 with a TiO2 content of 7.2 wt%.

[0094] In step (2), the mass of palladium nitrate (palladium content is 17.43 wt%) is 1.15 g; obtain the organic liquid dehydrogenation catalyst S7 (the component contents are shown in Table 1).

[0095] Example 8

[0096] According to the method described in Example 1, the difference is that

[0097] In step (1), the mass of pseudo-boehmite (dry basis content is 70 wt%) is 321.4 g, and the mass of TiO2 is 25 g; prepare the modified carrier C3 with a TiO2 content of 10 wt%; obtain the organic liquid dehydrogenation catalyst S8 (the component contents are shown in Table 1).

[0098] Example 9

[0099] According to the method described in Example 1, the difference is that

[0100] In step (1), reduce the calcination temperature from 800 °C to 650 °C; obtain the organic liquid dehydrogenation catalyst S9 (the component contents are shown in Table 1).

[0101] Example 10

[0102] According to the method described in Example 1, the difference is that

[0103] In step (1), increase the calcination temperature from 800 °C to 900 °C; obtain the organic liquid dehydrogenation catalyst S1 (the component contents are shown in Table 1).

[0104] Example 11

[0105] According to the method described in Example 1, the difference is that

[0106] In step (1), the calcination temperature was increased from 800 °C to 1000 °C; an organic liquid dehydrogenation catalyst S11 was obtained (the component contents are shown in Table 1).

[0107] Example 12

[0108] According to the method described in Example 1, the difference is that

[0109] In step (2), the mass of Fe(NO3)3·9H2O was 0.615 g, and the mass of Co(NO3)2·6H2O was 0.321 g; an organic liquid dehydrogenation catalyst S12 was obtained (the component contents are shown in Table 1).

[0110] Example 13

[0111] According to the method described in Example 1, the difference is that

[0112] In step (2), the mass of Fe(NO3)3·9H2O was 0.145 g, and the mass of Co(NO3)2·6H2O was 0.198 g; an organic liquid dehydrogenation catalyst S13 was obtained (the component contents are shown in Table 1).

[0113] Example 14

[0114] According to the method described in Example 1, the difference is that

[0115] In step (1), TiO2 was replaced with MgO in equal mass; an organic liquid dehydrogenation catalyst S14 was obtained (the component contents are shown in Table 1).

[0116] Example 15

[0117] According to the method described in Example 1, the difference is that

[0118] In step (1), TiO2 was replaced with SiO2 in equal mass; an organic liquid dehydrogenation catalyst S15 was obtained (the component contents are shown in Table 1).

[0119] Example 16

[0120] (1) Weigh 357.1 g of pseudo-boehmite (dry basis content 70 wt%) and 7.5 g of sesbania powder as raw material powder, and put the raw material powder into a kneader to mix evenly; weigh 1.92 g of nitric acid (concentration 65 wt%) and dissolve it in a certain amount of deionized water to prepare a dilute acid solution; add the above dilute nitric acid solution to the evenly mixed raw material powder, and continue to knead for 25 min; then extrude the kneaded sample, and then dry it in an oven at 100 °C for 4 h, and then transfer the dried sample to a muffle furnace and heat it to 800 °C at a heating rate of 3 °C / min and calcine for 4 h to obtain carrier C-4;

[0121] (2) Using the ethanol solution containing 10.653 g of tetrabutyl titanate as the impregnating solution, put the impregnating solution and 97.5 g of the C-4 support prepared in step (1) into a rotary evaporation container, impregnate at room temperature for 2 h, then dry at 120 °C for 2 h, and then transfer the sample to a muffle furnace and calcine at 800 °C for 4 h to obtain the modified support C4 with a TiO2 content of 2.5%;

[0122] (3) Carry out according to the method described in step (2) of Example 1, using C4 as the modified support; obtain the organic liquid dehydrogenation catalyst S16 (the component contents are shown in Table 1).

[0123] Comparative Example 1

[0124] (1) Prepare the support C-4 according to the method described in Example 16 (the component contents are shown in Table 1).

[0125] (2) Weigh 1.15 g of palladium nitrate (palladium content is 17.43 wt%) and dissolve it in a certain amount of dilute ammonia water solution (concentration is 3 wt%) as the impregnating solution; put the impregnating solution and 50 g of the support C-4 prepared in step (1) into a rotary evaporation container, impregnate at room temperature for 2 h, then dry at 120 °C for 2 h, and then transfer the sample to a muffle furnace and calcine at 450 °C for 4 h, and finally transfer the sample to a tubular furnace and reduce it under hydrogen at 350 °C for 3 h, and obtain the organic liquid dehydrogenation catalyst DS1 after cooling (the component contents are shown in Table 1).

[0126] Comparative Example 2

[0127] According to the method described in Example 1, the difference is that

[0128] In step (1), prepare the support C-4 according to the method described in Example 16 (the component contents are shown in Table 1);

[0129] In step (2), replace the modified support C1 with the support C-4; the obtained organic liquid dehydrogenation catalyst is denoted as DS2 (the component contents are shown in Table 1).

[0130] Comparative Example 3

[0131] According to the method described in Example 1, the difference is that

[0132] In step (2), do not add Co(NO3)2·6H2O; the obtained organic liquid dehydrogenation catalyst is denoted as DS3 (the component contents are shown in Table 1).

[0133] Comparative Example 4

[0134] According to the method described in Example 1, the difference is that

[0135] In step (2), Fe(NO3)3·9H2O is not added; the prepared organic liquid dehydrogenation catalyst is denoted as DS4 (the component contents are shown in Table 1).

[0136] Comparative Example 5

[0137] According to the method described in Example 1, the difference is that

[0138] In step (2), the mass of Fe(NO3)3·9H2O is 1.81 g, and the mass of Co(NO3)2·6H2O is 2.47 g; the prepared organic liquid dehydrogenation catalyst is denoted as DS5 (the component contents are shown in Table 1).

[0139] Comparative Example 6

[0140] According to the method described in Example 1, the difference is that

[0141] In step (1), the mass of pseudo-boehmite (dry basis content is 70 wt%) is 303.6 g, and the mass of TiO2 is 37.5 g; the modified carrier C5 with a TiO2 content of 15 wt% is prepared; the prepared organic liquid dehydrogenation catalyst is denoted as DS6 (the component contents are shown in Table 1).

[0142] Comparative Example 7

[0143] According to the method described in Example 1, the difference is that

[0144] In step (2), the mass of Fe(NO3)3·9H2O is 0.724 g, and the mass of Co(NO3)2·6H2O is 0.247 g; the prepared organic liquid dehydrogenation catalyst is denoted as DS7 (the component contents are shown in Table 1).

[0145] Table 1

[0146]

[0147] Note: The contents of the active metal and the promoter in Table 1 are based on the modified carrier.

[0148] Test Example

[0149] The organic liquid dehydrogenation catalysts prepared in the examples and comparative examples of the present invention are subjected to dehydrogenation reaction. The hydrogenated nitrogen-containing alkyl carbazole-based hydrogen storage material used is perhydro-N-methylcarbazole (12H-NMC), and the operating conditions are: the reaction pressure is 0.11 Mpa, the reaction temperature is 220 °C, and the reaction volume space velocity is 0.63 h -1, After reacting for 40 h, the product was collected and analyzed by gas chromatography for its composition. Among them, the reaction products were mainly octahydro-N-methylcarbazole (8H-NMC), tetrahydro-N-methylcarbazole (4H-NMC) and N-methylcarbazole (NMC). The purity of the hydrogen product and the molar amounts of each product were measured using a gas chromatograph. The dehydrogenation rate of 12H-NMC was calculated by the following formula, and the results are shown in Table 2.

[0150]

[0151] Among them, n1 is the molar amount of 12H-NMC in the sample, n2 is the molar amount of 8H-NMC, n3 is the molar amount of 4H-NMC, and n4 is the molar amount of NMC.

[0152] Table 2

[0153] Number Dehydrogenation rate % Hydrogen purity v / v % Example 1 91.3 99.9995 Example 2 91.2 99.9993 Example 3 89.9 99.9992 Example 4 89.7 99.9990 Example 5 89.1 99.9987 Example 6 88.5 99.9983 Example 7 90.2 99.9992 Example 8 90.5 99.9989 Example 9 89.7 99.9943 Example 10 91.1 99.9993 Example 11 88.6 99.9979 Example 12 89.5 99.9981 Example 13 88.9 99.9975 Example 14 90.8 99.9993 Example 15 89.5 99.9985 Example 16 90.6 99.9991 Comparative Example 1 86.9 99.9902 Comparative Example 2 88.2 99.9933 Comparative Example 3 87.6 99.9891 Comparative Example 4 87.9 99.9915 Comparative Example 5 84.3 99.9876 Comparative Example 6 86.8 99.9945 Comparative Example 7 87.2 99.9915

[0154] From the results of Table 1 and Table 2, it can be seen that the organic liquid dehydrogenation catalyst prepared in the embodiment of the present invention has high dehydrogenation activity and hydrogen purity in the dehydrogenation reaction of nitrogen-containing alkylcarbazole-based hydrogen storage materials. By comparing the examples and the comparative examples, it can be seen that the active component of the noble metal / Fe / Co composite provided by the present invention, in synergistic action with the modified carrier, can have better 12H-NMC dehydrogenation activity and higher hydrogen purity than the pure noble metal dehydrogenation catalyst, effectively solving the problem of low hydrogen purity in the process of organic liquid dehydrogenation.

[0155] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. An organic liquid dehydrogenation catalyst, characterized in that, The catalyst includes a modified support, and an active metal component and a promoter component supported on the modified support; the promoter component includes Fe and Co; in terms of elements, the mass ratio of Fe to Co in the promoter component is 1:0.7 - 2.8; The active metal component is at least one of noble metals; the modified support includes alumina and a modifying component, and the modifying component includes at least one of TiO2, SiO2, and MgO; The mass ratio of the modifying component to the alumina is 1 - 13:100; In terms of elements, the mass ratio of the promoter component to the active metal component is 0.2 - 2:

1.

2. The organic liquid dehydrogenation catalyst according to claim 1, wherein In terms of elements, the mass ratio of Fe to Co in the promoter component is 1:1 - 2.5; The mass ratio of the modifying component to the alumina is 2 - 12:100; In terms of elements, the mass ratio of the promoter component to the active metal component is 0.3 - 1.6:

1.

3. The organic liquid dehydrogenation catalyst according to claim 1, wherein, Based on the mass of the modified support, the content of alumina is 88 - 99 wt%; the content of the modifying component is 1 - 12 wt%; Based on the mass of the modified support, in terms of elements, the content of the active metal component is 0.1 - 1 wt%, and the content of the promoter component is 0.1 - 1 wt%.

4. The organic liquid dehydrogenation catalyst according to claim 1, wherein, The noble metal is Pd and / or Pt; The modifying component is TiO2.

5. A method for preparing an organic liquid dehydrogenation catalyst, characterized in that, It includes the following steps: (1) Mix an alumina precursor and a modifying component precursor, and obtain a modified support through shaping; The mass ratio of the modifying component precursor in terms of oxide to the alumina precursor based on dry basis is 1 - 13:100; (2) Load the active metal component and the promoter component on the modified support to obtain a catalyst intermediate; In terms of elements, the mass ratio of the promoter component to the active metal component is 0.2 - 2:1; (3) Calcinate and reduce the catalyst intermediate; The modifying component precursor includes at least one of a Ti source, an Si source, and an Mg source; the promoter component includes Fe and Co; in terms of elements, the mass ratio of Fe to Co is 1:0.7 - 2.8; the active metal component is at least one of noble metals.

6. The preparation method according to claim 5, wherein, The mass ratio of the modifying component precursor in terms of oxide to the alumina precursor based on dry basis is 2 - 12:100; Preferably, the amounts of the alumina precursor and the modifying component precursor are such that, based on the total mass of the modified support, the content of alumina is 88 - 99 wt%; the content of the modifying component is 1 - 12 wt%. Preferably, the alumina precursor is pseudo-boehmite; Preferably, the Ti source is selected from at least one of TiO2, TiCl4, and tetrabutyl titanate; Preferably, the Si source is SiO2 and / or silica sol; Preferably, the Mg source is selected from at least one of magnesium oxide, magnesium nitrate, magnesium acetate, and basic magnesium carbonate; Preferably, the modifying component precursor is the Ti source.

7. The preparation method according to claim 5, wherein, Step (1) further includes: drying and calcining the shaped product; Preferably, the temperature of the drying is 100 - 150 °C, and the time of the drying is 2 - 5 h; Preferably, the temperature of the calcining is 500 - 1000 °C; Preferably, the conditions for the calcination further include: a heating rate of 1-5 °C / min; a time of 1-6 h.

8. The preparation method according to claim 5, wherein, In step (2), based on elements, the mass ratio of the promoter component to the active metal component is 0.3-1.6:1; Preferably, based on elements, the mass ratio of Fe to Co is 1:1-2.5; Preferably, the active metal component is Pd and / or Pt; Preferably, the method for loading in step (2) includes: impregnating the modified support with an impregnation solution containing a precursor of the active metal component and a precursor of the promoter component, and then drying; Preferably, the temperature of the impregnation is 20-40 °C, and the time of the impregnation is 1-3 h; Preferably, the temperature of the drying is 100-150 °C, and the time of the drying is 2-5 h; Preferably, the precursor of the active metal component is a soluble compound containing the noble metal; Preferably, the amounts of the impregnation solution and the modified support are such that, based on the total mass of the modified support, the content of the active metal component is 0.1-1 wt, and the content of the promoter component is 0.1-1 wt%; 9. The preparation method according to claim 5, wherein, In step (3), the conditions for the calcination include: a temperature of 350-600 °C; a time of 2-6 h; Preferably, the conditions for the reduction include: under a reducing atmosphere, a reduction temperature of 200-400 °C; a reduction time of 2-8 h.

10. A method for dehydrogenating an organic liquid, characterized in that, Contact the hydrogenated organic liquid with a catalyst, which is the organic liquid dehydrogenation catalyst according to any one of claims 1-4 or the organic liquid dehydrogenation catalyst prepared by the method according to any one of claims 5-9. Preferably, the organic liquid is a nitrogen-containing heterocyclic material; Preferably, the conditions for the contact include: a reaction pressure of 0.07 - 0.13 MPa; a reaction temperature of 170 - 240 °C; a volume space velocity of 0.2 - 1.5 h -1 .

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