Catalyst for dehydrogenation of perhydrodibenzyltoluene as well as preparation method and application of catalyst

Abstract

The invention provides a catalyst for dehydrogenation of perhydrodibenzyltoluene as well as a preparation method and application thereof, the catalyst comprises a first metal additive, a metal cluster and a molecular sieve carrier, and the metal cluster comprises a noble metal active component and a second metal additive; the first metal additive and the metal clusters are distributed on the molecular sieve carrier; the particle size of the metal cluster is less than 1nm. Wherein the molecular sieve carrier stabilizes the metal clusters in pore channels and on the outer surface of the molecular sieve carrier under the action of physical confinement, the particle size of the metal clusters is less than 1nm, the specific surface area is large, more active sites can be provided, and the introduction of the first metal additive can promote the dispersion of the metal clusters, increase the contact area of the catalyst and reactants, and improve the catalytic activity of the catalyst. The catalytic efficiency is further improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of hydrogen storage materials, in particular to a catalyst for dehydrogenation of perhydrodibenzyltoluene, a preparation method thereof and application thereof. BACKGROUND

[0002] With global warming and the reduction of fossil fuels, governments, organizations and researchers are increasingly attaching importance to the application of renewable energy. Hydrogen, as a clean secondary energy, has the advantages of reducing environmental impact, being inexhaustible and improving economic efficiency. However, due to the flammable and explosive characteristics of hydrogen, its storage and transportation have become a major problem. The liquid organic hydrogen carrier (LOHC) system is a flexible and safe method for hydrogen storage and transportation. Among many LOHCs, perhydrodibenzyltoluene (H18-DBT) / dibenzyltoluene (DBT) has attracted widespread attention from the academic and industrial communities due to its excellent hydrogen storage capacity and good thermal stability.

[0003] The main use of H18-DBT / DBT at present is heat transfer oil in industry, which is low in price but exhibits excellent performance in hydrogenation and dehydrogenation. It can easily undergo hydrogenation at a relatively low temperature, but due to the limitation of thermodynamics, the dehydrogenation of H18-DBT is difficult to proceed even at a relatively high temperature, which requires the development of high-efficiency catalysts to promote the reaction. At present, researchers mainly focus on developing catalysts suitable for H18-DBT hydrogenation and dehydrogenation. Noble metal catalysts such as platinum, palladium and ruthenium exhibit excellent activity. These noble metal catalysts are widely studied due to their good electronic structure and moderate adsorption strength. Among them, platinum-based catalysts exhibit the most excellent performance in H18-DBT dehydrogenation, especially nanoparticle-sized platinum catalysts can significantly improve the catalytic activity and selectivity. One document reports that by using alumina supports with different morphologies to load Pt, a series of perhydrodibenzyltoluene dehydrogenation catalysts are prepared, which have the advantages of high activity, high dehydrogenation efficiency and high dehydrogenation reaction stability; another document reports that Pt is used as an active site and second metal additives such as molybdenum, vanadium, rhenium, lanthanum or cerium are added, which are loaded on alumina, silica, activated carbon, zirconia, titania or molecular sieve supports, and the prepared catalysts exhibit excellent dehydrogenation activity, and the introduction of the second metal improves the stability of the catalysts.

[0004] However, although the noble metal catalysts perform well in performance, they will be deactivated due to carbon deposition after long time use, which not only comes from the noble metal active sites, but also possibly from the acid sites of the carrier, thus, the catalyst needs to be further modified to improve its stability and life; secondly, the large use of noble metals will increase the cost of the catalyst, therefore, how to improve the activity of the catalyst and reduce its dosage is also one of the current research directions. SUMMARY

[0005] In view of the above problems existing in the prior art, the present application provides a catalyst for dehydrogenation of perhydrodibenzyltoluene, a preparation method thereof and an application thereof. The molecular sieve carrier stably holds the metal cluster in the pore channel and the outer surface of the molecular sieve carrier through the physical confinement effect, the particle size of the metal cluster is less than 1 nm, the specific surface area is large, more active sites can be provided, and the introduction of the first metal additive can promote the dispersion of the metal cluster, increase the contact area of the catalyst and the reactants, and thus improve the catalytic efficiency.

[0006] In the first aspect, the present application provides a catalyst for dehydrogenation of perhydrodibenzyltoluene, which comprises a first metal additive, a metal cluster and a molecular sieve carrier, the metal cluster comprises a noble metal active component and a second metal additive; the first metal additive and the metal cluster are distributed on the molecular sieve carrier; the particle size of the metal cluster is less than 1 nm.

[0007] In some embodiments, the mass percentage content of the active component is 0.05% to 0.5%, preferably 0.3% to 0.4%, based on the mass of the catalyst; the mass percentage content of the first metal additive is 0.05% to 1.0%, preferably 0.6% to 0.8%; the mass percentage content of the second metal additive is 0.1% to 3.0%, preferably 1.0% to 2.2%; the mass percentage content of the molecular sieve carrier is 95.5% to 99.8%, preferably 96.6% to 98.1%. The introduction of an appropriate amount of the first metal additive can occupy a specific lattice position, modify the dispersibility and electronic effect of the noble metal active component, so that a small amount of active component can expose a larger active surface area, reduce the amount of active component, and further improve the catalytic performance of the active component of the catalyst, thereby reducing the cost of the catalyst for industrialization; secondly, the introduction of an appropriate amount of the second metal additive can form a stable metal cluster with the noble metal active component, change the electronic density of the active component, and adjust the active center and lattice constant of the metal cluster, thereby effectively inhibiting the migration and agglomeration of the active component, and further improving the stability and carbon deposition resistance of the catalyst.

[0008] In some embodiments, the average particle size of the metal cluster is 0.6 nm to 0.9 nm. Controlling the average particle size of the metal cluster in this range provides the active component with a higher surface energy, thereby providing more active sites and improving the catalytic activity of the catalyst.

[0009] In some embodiments, the noble metal active component comprises one or more of Rh, Pt.

[0010] In some embodiments, the first metal promoter can be selected from alkali metals of Group IA or alkaline earth metals of Group IIA, including but not limited to one or more of K, Rb, and Cs. These metal promoters can adjust the ionic radius, charge effect, surface energy, and chemical stability of the active component. First, the alkali metals and alkaline earth metals have a large ionic radius, which can form a large ionic field on the surface of the catalyst, thereby making the noble metal active component more uniformly distributed on the surface, avoiding agglomeration, and thereby adjusting the ionic radius and charge effect. Second, these metal promoters can adjust the surface energy of the active component, making the active component more easily dispersed on the surface of the catalyst, thereby increasing the surface area and activity of the catalyst. Third, alkali metals and alkaline earth metals generally have high chemical stability and can remain stable at high temperatures and reaction atmospheres, thereby enhancing the overall stability and service life of the catalyst.

[0011] In some embodiments, the second metal promoter comprises one or more of Sn, Ge, Fe, and Mn. The second metal promoter has good alloy-forming ability with the active component Rh, Pt, etc., and can form stable metal clusters, wherein the second metal promoter can act as an electron donor or acceptor, changing the electron density of the active component, thereby improving the catalytic activity and stability of the active component. For example, Sn can provide electrons to the active component Rh, Pt, changing its surface electronic structure through electronic and geometric effects, thereby adjusting the dispersion of the active component Rh, Pt, and thereby improving the catalytic activity; Fe improves the desorption of dibenzyltoluene, thereby improving the catalytic selectivity; when Sn and Fe are added together, the adjacency of Sn, Fe, and Pt at the atomic level allows the construction of multifunctional active sites for effective C-H bond activation, promoting the progress of the catalytic reaction, and thereby exhibiting excellent catalytic activity.

[0012] In some embodiments, the molecular sieve carrier comprises a full-silica or high-silica composition molecular sieve carrier with an MFI topology. The pure silica or high-silica composition structure and composition can effectively eliminate or reduce the acidity of the internal and external surfaces of the molecular sieve carrier, thereby reducing side reactions such as cracking and cyclization during the dehydrogenation process and inhibiting carbon deposition. In some embodiments, the molecular sieve carrier comprises one or more of Silicalite-1, ZSM-5, and TS-1.

[0013] In a second aspect, the present application provides a preparation method of the catalyst, and the preparation method comprises:

[0014] S1, mixing a molecular sieve template agent, a silicon source, a water-soluble compound of the first metal additive, and water to obtain a mixed slurry through hydrolysis;

[0015] S2, mixing a water-soluble compound of the noble metal active component and a water-soluble metal salt of the second metal additive with ethylenediamine to obtain a mixed solution;

[0016] S3, mixing the mixed solution obtained in step S2 and the mixed slurry obtained in step S1, and then performing hydrothermal crystallization treatment, followed by centrifugation, washing, drying, and calcination to obtain the catalyst.

[0017] The catalyst required by the present application can be directly prepared by the one-pot synthesis method, and the preparation process is simple. The catalyst is used for the dehydrogenation reaction of perhydrodibenzyltoluene, and exhibits high dehydrogenation rate, high selectivity, and high stability.

[0018] In some embodiments, the molecular sieve template agent comprises one or more of tetrapropylammonium hydroxide, tetraethylammonium hydroxide, and tetramethylammonium hydroxide.

[0019] In some embodiments, the silicon source comprises one or more of tetramethyl orthosilicate, tetraethyl orthosilicate, silica sol, sodium silicate, and tetrabutyl orthosilicate.

[0020] In some embodiments, the water-soluble compound of the first metal additive comprises one or more of KCl, KNO3, K2SO4, KOH, RbCl, RbNO3, CsCl, and CsNO3.

[0021] In some embodiments, the water-soluble compound of the active component comprises one or more of chloroplatinic acid, ammonium hexachloroplatinate, platinum chloride, rhodium trichloride, rhodium nitrate, and ammonium pentachlororhodate hydrate.

[0022] In some embodiments, the water-soluble metal salt of the second metal additive comprises one or more of tin tetrachloride, stannous chloride, stannous nitrate, stannous sulfate, germanium tetrachloride, ammonium germanate, germanium nitrate, iron chloride, iron sulfate, iron nitrate, potassium permanganate, and ammonium permanganate.

[0023] In some embodiments, in step S1, the hydrolysis is performed at 30-50°C for 3-12h.

[0024] In some embodiments, in step S3, the hydrothermal crystallization treatment is performed at 150-200°C for 24-144h.

[0025] In some embodiments, in step S3, the drying condition is: 90-130℃ for 8-24h.

[0026] In some embodiments, in step S3, the calcination condition is: 450-700℃ for 2-15h in air atmosphere.

[0027] In some embodiments, in step S2, the mass ratio of the water-soluble compound of the active component to ethylenediamine is 1:(2-50).

[0028] In a third aspect, the application provides a use of the above-mentioned catalyst or the catalyst prepared according to the above-mentioned method in a dehydrogenation reaction of perhydrodibenzyltoluene.

[0029] In some embodiments, in the above-mentioned dehydrogenation process, the reaction temperature is 300-500℃, the reaction pressure is 0.1-1.0MPa, the mass space velocity of the perhydrodibenzyltoluene raw material is 5-50h -1 , the reaction carrier gas of the dehydrogenation reaction is hydrogen and / or nitrogen, and the molar ratio of the reaction carrier gas to the perhydrodibenzyltoluene raw material is (2-10):1.

[0030] In some embodiments, before the dehydrogenation process, the catalyst is subjected to a reduction treatment in a hydrogen atmosphere; in the reduction process, the reduction temperature is 300-500℃, and the reduction time is 1-5h.

[0031] In some embodiments, the dehydrogenation reaction can be carried out in a fixed bed, a fluidized bed or a moving bed for continuous production to obtain high-purity hydrogen.

[0032] Advantages:

[0033] The catalyst for dehydrogenation of perhydrodibenzyltoluene provided by the application can stabilize the metal clusters in the pores and outer surface of the molecular sieve carrier by physical confinement, the particle size of the metal clusters is less than 1nm, the specific surface area is large, and more active sites can be provided. The introduction of the first metal additive can promote the dispersion of the metal clusters and increase the contact area of the catalyst and the reactants; the introduction of the second metal additive can form stable metal clusters with the noble metal active component, the second metal additive can act as an electron donor or acceptor to change the electron density of the active component, improve the catalytic activity, and further improve the catalytic efficiency.

[0034] In summary, the synergistic effect of the first metal promoter and the second metal promoter can adjust the dispersity of the active component and the electronic effect, so that a small amount of active component can expose a larger active surface area, reduce the amount of active component, and further improve the catalytic performance of the catalyst active component, reduce the cost of the catalyst for industrialization, and the catalyst can catalyze the dehydrogenation reaction of the organic liquid hydrogen storage material, and exhibit high dehydrogenation rate, high selectivity and high stability. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 XRD crystal pattern diagrams of the catalysts of embodiments 1-6 of the present application are shown.

[0036] Figure 2a A TEM diagram of the catalyst of embodiment 1 of the present application is shown.

[0037] Figure 2b A TEM diagram of the catalyst of embodiment 2 of the present application is shown.

[0038] Figure 2c A TEM diagram of the catalyst of embodiment 3 of the present application is shown.

[0039] Figure 2d A TEM diagram of the catalyst of embodiment 4 of the present application is shown.

[0040] Figure 2e A TEM diagram of the catalyst of embodiment 5 of the present application is shown.

[0041] Figure 2f A TEM diagram of the catalyst of embodiment 6 of the present application is shown. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described clearly and completely below in conjunction with embodiments. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. The embodiments described herein are illustrative in nature and are used to provide a basic understanding of the present application. The embodiments of the present application should not be interpreted as a limitation of the present application.

[0043] For the sake of brevity, only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with any other lower limit to form a range not explicitly recited, and likewise any upper limit can be combined with any other upper limit to form a range not explicitly recited. Further, each individual disclosed point or single numerical value can be combined with any other point or single numerical value to form a range not explicitly recited, either as a lower limit or an upper limit, or in combination with other lower limits or upper limits.

[0044] In the description herein, unless otherwise stated, "above", "below" include the number.

[0045] In the description herein, "sub-nanometer metal cluster" refers to a metal cluster with a particle size less than 1 nm.

[0046] Unless otherwise defined, all terms used in the present application have the meanings commonly understood by those skilled in the art. Unless otherwise stated, the numerical values of each parameter mentioned in the present application can be measured by various measurement methods commonly used in the art (for example, can be tested according to the method given in the examples of the present application).

[0047] In the detailed description and in the claims, a list of items joined by the term "at least one of" or "one or more of" can mean any combination of the items in the list. For example, if the list contains A and B, then "at least one of A and B" means only A; only B; or A and B. In another example, if the list contains A, B, and C, then "at least one of A, B, and C" means A alone; B alone; C alone; A and B (excluding C); A and C (excluding B); B and C (excluding A); or A, B, and C.

[0048] In a first aspect, the present application provides a catalyst for dehydrogenation of perhydrodibenzyltoluene, comprising a first metal promoter, a metal cluster and a molecular sieve carrier, the metal cluster comprising a noble metal active component and a second metal promoter; the first metal promoter and the metal cluster are distributed on the molecular sieve carrier; the particle size of the metal cluster is less than 1 nm.

[0049] In the present application, the molecular sieve carrier stabilizes the metal cluster in the pore channel and on the outer surface of the molecular sieve carrier by physical confinement, the particle size of the metal cluster is less than 1 nm, the specific surface area is larger, and more active sites can be provided. Among them, the introduction of the first metal promoter can promote the dispersion of the metal cluster and increase the contact area of the catalyst with the reactants; the introduction of the second metal promoter can form a stable metal cluster with the noble metal active component, and the second metal promoter can change the electron density of the active component as an electron donor or acceptor, improve the catalytic activity, and further improve the catalytic efficiency. In summary, the synergistic effect of the first metal promoter and the second metal promoter can adjust the dispersibility and electronic effect of the active component, so that a small amount of active component can expose a larger active surface area, reduce the amount of active component while further improving the catalytic performance of the active component of the catalyst, reduce the cost of the catalyst for industrialization, and the catalyst can catalyze the dehydrogenation reaction of organic liquid hydrogen storage materials, showing high dehydrogenation rate, high selectivity and high stability.

[0050] In some embodiments, the mass percentage of the noble metal active component is 0.05% to 0.5%, the mass percentage of the first metal promoter is 0.05% to 1.0%, the mass percentage of the second metal promoter is 0.1% to 3.0%, and the mass percentage of the molecular sieve carrier is 95.5% to 99.8%, based on the mass of the catalyst. The introduction of an appropriate amount of the first metal promoter can occupy specific lattice positions, adjust the dispersion and electronic effect of the active component, so that a small amount of the active component can expose a larger active surface area, reduce the amount of the active component, and further improve the catalytic performance of the active component of the catalyst, thereby reducing the cost of the catalyst for industrialization. In addition, the introduction of an appropriate amount of the second metal promoter can form stable metal clusters with the noble metal active component, change the electronic density of the active component, and adjust the active center and lattice constant of the metal clusters, thereby effectively inhibiting the migration and agglomeration of the active component, and further improving the stability and carbon deposition resistance of the catalyst.

[0051] In some embodiments, the mass percentage of the active component is 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, or a range between any two of these values.

[0052] In some embodiments, the mass percentage of the first metal promoter is 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or a range between any two of these values.

[0053] In some embodiments, the mass percentage of the second metal promoter is 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.2%, 2.4%, 2.6%, 2.8%, 3.0%, or a range between any two of these values.

[0054] In some embodiments, the mass percentage of the molecular sieve carrier is 95.5%, 95.6%, 95.8%, 96.0%, 96.2%, 96.4%, 96.6%, 96.8%, 97.0%, 97.2%, 97.4%, 97.6%, 97.8%, 98.0%, 98.2%, 98.4%, 98.6%, 98.8%, 99.0%, 99.2%, 99.4%, 99.6%, 99.8%, or a range between any two of these values.

[0055] In some embodiments, the mass percentage of the noble metal active component is 0.3% to 0.4%, the mass percentage of the first metal promoter is 0.6% to 0.8%, the mass percentage of the second metal promoter is 1.0% to 2.2%, and the mass percentage of the molecular sieve carrier is 96.6% to 98.1%, based on the mass of the catalyst. Within this range, the first metal promoter and the second metal promoter synergistically improve the activity, selectivity, and stability of the catalyst.

[0056] In some embodiments, the average particle size of the metal cluster is 0.6 nm to 0.9 nm. Controlling the average particle size of the metal cluster within this range provides the active component with higher surface energy, thereby providing more active sites and improving the catalytic activity of the catalyst. In some embodiments, the average particle size of the metal cluster is 0.60 nm, 0.65 nm, 0.70 nm, 0.75 nm, 0.80 nm, 0.85 nm, 0.90 nm, or a range defined by any two of these values.

[0057] In some embodiments, the noble metal active component includes one or more of Rh and Pt.

[0058] In some embodiments, the first metal promoter can be selected from Group IA alkali metals or Group IIA alkaline earth metals, including but not limited to one or more of K, Rb, and Cs. These metal promoters can adjust the ionic radius, charge effect, surface energy, and chemical stability of the active component. First, the ionic radius of alkali metals and alkaline earth metals is large, which can form a large ionic field on the surface of the catalyst, thereby making the noble metal active component more uniformly distributed on the surface, avoiding agglomeration, and thereby adjusting the ionic radius and charge effect. Second, these metal promoters can adjust the surface energy of the active component, making the active component more easily dispersed on the surface of the catalyst, thereby increasing the surface area and activity of the catalyst. Third, alkali metals and alkaline earth metals generally have high chemical stability, which can remain stable at high temperatures and reaction atmospheres, thereby enhancing the overall stability and service life of the catalyst.

[0059] In some embodiments, the second metal promoter includes one or more of Sn, Ge, Fe and Mn. The second metal promoter has good alloy forming ability with the active component Rh, Pt, etc., and can form stable metal clusters, wherein the second metal promoter can act as an electron donor or acceptor, capable of changing the electron density of the active component, thereby improving the catalytic activity and stability of the active component. For example, Sn can provide electrons to the active component Rh, Pt, and change its surface electronic structure through electronic effect and geometric effect, thereby adjusting the dispersion of the active component Rh, Pt, and thereby improving the catalytic activity; Fe can improve the desorption of dibenzyltoluene, thereby improving the catalytic selectivity; when Sn and Fe are added together, the adjacency of Sn, Fe and Pt at the atomic level allows the construction of multifunctional active sites for effective C-H bond activation, promoting the progress of the catalytic reaction, and thereby exhibiting excellent catalytic activity.

[0060] In some embodiments, the molecular sieve carrier includes a full-silicon or high-silicon composition molecular sieve carrier with MFI topology. The pure silicon or high-silicon composition structure and composition can effectively eliminate or reduce the acidity of the inner and outer surfaces of the molecular sieve carrier, thereby reducing side reactions such as cracking and cyclization during the dehydrogenation process, and inhibiting carbon deposition. In some embodiments, the molecular sieve carrier includes one or more of Silicalite-1, ZSM-5 and TS-1.

[0061] In a second aspect, the application provides a preparation method of the above-mentioned catalyst, the preparation method comprising:

[0062] S1, mixing a molecular sieve template agent, a silicon source, a water-soluble compound of the first metal promoter and water, and hydrolyzing to obtain a mixed slurry;

[0063] S2, mixing a water-soluble compound of the noble metal active component, a water-soluble metal salt of the second metal promoter and ethylenediamine to obtain a mixed solution;

[0064] S3, mixing the mixed solution of step S2 and the mixed slurry of step S1, and performing hydrothermal crystallization treatment, followed by centrifugation, washing, drying and calcination to obtain the catalyst.

[0065] The catalyst required by the application can be directly prepared by the one-pot synthesis method described above, and the preparation process is simple. The catalyst is used for the dehydrogenation reaction of perhydrodibenzyltoluene, and exhibits high dehydrogenation rate, high selectivity and high stability.

[0066] In some embodiments, the molecular sieve template agent includes one or more of tetrapropylammonium hydroxide, tetraethylammonium hydroxide and tetramethylammonium hydroxide.

[0067] In some embodiments, the silicon source comprises one or more of tetramethylorthosilicate, tetraethylorthosilicate, silica sol, sodium silicate, and tetrabutylorthosilicate.

[0068] In some embodiments, the water-soluble compound of the first metal promoter comprises one or more of KCl, KNO3, K2SO4, KOH, RbCl, RbNO3, CsCl, and CsNO3.

[0069] In some embodiments, the water-soluble compound of the active component comprises one or more of chloroplatinic acid, ammonium hexachloroplatinate, platinum chloride, rhodium trichloride, rhodium nitrate, and ammonium pentachloro rhodate hydrate.

[0070] In some embodiments, the water-soluble metal salt of the second metal promoter comprises one or more of tin tetrachloride, stannous chloride, stannous nitrate, stannous sulfate, germanium tetrachloride, ammonium germanate, germanium nitrate, iron chloride, iron sulfate, iron nitrate, potassium permanganate, and ammonium permanganate.

[0071] In some embodiments, in step S1, the hydrolysis is performed at a temperature of 30-50 °C for a time period of 3-12 h. In some embodiments, the temperature of the hydrolysis can be controlled to be 30 °C, 32 °C, 34 °C, 36 °C, 38 °C, 40 °C, 42 °C, 44 °C, 46 °C, 48 °C, 50 °C, or a range defined by any two of these values. In some embodiments, the stirring time of the hydrolysis can be controlled to be 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, or a range defined by any two of these values.

[0072] In some embodiments, in step S3, the hydrothermal crystallization is performed at a temperature of 150-200 °C for a time period of 24-144 h. In some embodiments, the temperature of the hydrothermal crystallization can be controlled to be 150 °C, 155 °C, 160 °C, 165 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 195 °C, 200 °C, or a range defined by any two of these values. In some embodiments, the stirring time of the hydrothermal crystallization can be controlled to be 24 h, 30 h, 40 h, 50 h, 60 h, 70 h, 80 h, 90 h, 100 h, 110 h, 120 h, 130 h, 140 h, 144 h, or a range defined by any two of these values.

[0073] In some embodiments, in step S3, the drying condition is: 90-130°C for 8-24h. In some embodiments, the drying temperature can be controlled at 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, or a range between any two of these values. In some embodiments, the drying time can be controlled at 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h, or a range between any two of these values.

[0074] In some embodiments, in step S3, the calcination condition is: 450-700°C for 2-15h in air atmosphere. In some embodiments, the drying temperature can be controlled at 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, or a range between any two of these values. In some embodiments, the drying time can be controlled at 2h, 4h, 6h, 8h, 10h, 12h, 14h, 15h, or a range between any two of these values.

[0075] In some embodiments, in step S2, the mass ratio of the water-soluble compound of the active component to ethylenediamine is 1:(2-50). In some embodiments, the mass ratio of the water-soluble compound of the active component to ethylenediamine is 1:2, 1:5, 1:10, 1:15, 1:20, 1:25, 1:30, 1:35, 1:40, 1:45, 1:50, or a range between any two of these values.

[0076] In a third aspect, the present application provides a use of the above-mentioned catalyst or the catalyst prepared according to the above-mentioned method in a dehydrogenation reaction of perhydrodibenzyltoluene.

[0077] In some embodiments, in the above-mentioned dehydrogenation process, the reaction temperature is 300-500°C. In some embodiments, the reaction temperature is 300°C, 320°C, 340°C, 360°C, 380°C, 400°C, 420°C, 440°C, 460°C, 480°C, 500°C, or a range between any two of these values.

[0078] In some embodiments, the reaction pressure of the dehydrogenation reaction is 0.1-1.0 MPa. In some embodiments, the reaction pressure is 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, 1.0 MPa, or a range between any two of these values.

[0079] In some embodiments, the mass space velocity of the perhydrodibenzyltoluene raw material feed is 5-50 h-1 In some embodiments, the mass hourly space velocity of the perhydrodibenzyltoluene feedstock is 5 h -1 , 10 h -1 , 15 h -1 , 20 h -1 , 25 h -1 , 30 h -1 , 35 h -1 , 40 h -1 , 45 h -1 , 50 h -1 or a range consisting of any two of these values.

[0080] In some embodiments, the reaction carrier gas of the dehydrogenation reaction is hydrogen and / or nitrogen.

[0081] In some embodiments, the molar ratio of the reaction carrier gas of the dehydrogenation reaction to the feedstock of the perhydrodibenzyltoluene is (2-10):1. In some embodiments, the molar ratio of the reaction carrier gas of the dehydrogenation reaction to the feedstock of the perhydrodibenzyltoluene is 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1 or a range consisting of any two of these values.

[0082] In some embodiments, the catalyst is reduced under hydrogen atmosphere before the dehydrogenation process. In some embodiments, the reduction temperature is 300-500°C and the reduction time is 1-5 h. In some embodiments, the reduction temperature is 300°C, 320°C, 340°C, 360°C, 380°C, 400°C, 420°C, 440°C, 460°C, 480°C, 500°C or a range consisting of any two of these values. In some embodiments, the reduction time is 1 h, 2 h, 3 h, 4 h, 5 h or a range consisting of any two of these values.

[0083] In some embodiments, the dehydrogenation reaction can be carried out continuously using a fixed bed, a fluidized bed or a moving bed to produce high purity hydrogen.

[0084] Examples and Comparative Examples

[0085] The following examples and comparative examples are provided to further illustrate the present application, but the present application is not limited to these examples.

[0086] The materials and reagents used in the following examples were obtained from commercial sources.

[0087] Preparation of the catalyst

[0088] Example 1

[0089] The catalyst of this example has a composition of 0.3wt% Pt, 0.6wt% K, 1.0wt% Sn and 98.1wt% MFI molecular sieve (Silicalite-1 molecular sieve), denoted as catalyst Cat1#, which is prepared according to the following steps:

[0090] S1, 81.2g of tetrapropylammonium hydroxide solution (40wt% in mass fraction), 82.4g of tetraethyl orthosilicate, 0.27g of potassium chloride and 201.2g of water are mixed in an autoclave, and hydrolysis is carried out under stirring at 35°C for 6h to obtain a mixed slurry;

[0091] S2, 0.15g of chloroplatinic acid is mixed with 0.52g of tin tetrachloride and 4.5g of ethylenediamine to obtain a mixed solution;

[0092] S3, the mixed solution in step S2 is added to the mixed slurry in step S1, and after hydrothermal crystallization at 170°C for 96h, centrifugation, washing and drying at 110°C for 12h, calcination at 560°C for 5h in an air atmosphere is carried out to obtain the catalyst Cat1# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen.

[0093] A small amount of catalyst Cat1# is reduced at 400°C under a hydrogen atmosphere for 4h, and electron microscopy analysis shows that the average size of Pt metal clusters is about 0.8nm.

[0094] The catalyst Cat1# is used as a catalyst for dehydrogenation reaction of perhydrodibenzyltoluene with hydrogen as a carrier gas, and the specific process is as follows:

[0095] A fixed bed reactor containing 5g of catalyst Cat1# is continuously fed with hydrogen, heated to 350°C and reduced for 3h, then the temperature is kept unchanged, the amount of H2 feed and the amount of perhydrodibenzyltoluene feed are adjusted, and the molar ratio of perhydrodibenzyltoluene to hydrogen is 1:4, the pressure of the reactor is 0.1MPa, the mass space velocity of perhydrodibenzyltoluene is 15h -1 , and the reaction product is obtained, which is analyzed online by gas chromatography.

[0096] Example 2

[0097] The catalyst of this example has a composition of 0.3wt% Pt, 0.6wt% K, 1.0wt% Sn, 1.2wt% Fe and 96.9wt% MFI molecular sieve (Silicalite-1 molecular sieve), denoted as catalyst Cat2#, which is prepared according to the following steps:

[0098] S1, 81.2g of tetrapropylammonium hydroxide solution (40wt% in mass fraction), 82.4g of tetraethyl orthosilicate, 0.27g of potassium chloride and 201.2g of water are mixed in an autoclave, and hydrolysis is carried out under stirring at 35°C for 6h to obtain a mixed slurry;

[0099] S2, 0.15 g chloroplatinic acid was mixed with 0.52 g tin tetrachloride, 1.23 g iron nitrate, 4.5 g ethylenediamine to obtain a mixed solution;

[0100] S3, the mixed solution in step S2 was added to the mixed slurry in step S1, after hydrothermal crystallization at 170°C for 96 h, centrifugation, washing, drying at 110°C for 12 h, and calcination at 560°C for 5 h in air atmosphere, a catalyst Cat2# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen was obtained.

[0101] A small amount of catalyst Cat2# was reduced at 400°C for 4 h in a hydrogen atmosphere, and the average size of Pt metal clusters was about 0.7 nm by electron microscopy analysis.

[0102] The catalyst Cat2# was used as a catalyst for dehydrogenation reaction of perhydrodibenzyltoluene with hydrogen as a carrier gas, as follows:

[0103] A fixed bed reactor containing 5 g of catalyst Cat2# was continuously fed with hydrogen, heated to 350°C for 3 h, and then the temperature was kept constant. The H2 feed rate and the perhydrodibenzyltoluene feed rate were adjusted to a molar ratio of 1:4, the reactor pressure was 0.1 MPa, and the perhydrodibenzyltoluene feed mass space velocity was 15 h -1 , to obtain the reaction product, which was analyzed online by gas chromatography.

[0104] Example 3

[0105] The catalyst composition of this example was 0.3 wt% Pt, 0.6 wt% K, 1.2 wt% Fe and 97.9 wt% MFI molecular sieve (Silicalite-1 molecular sieve), denoted as catalyst Cat3#, which was prepared as follows:

[0106] S1, 81.2 g of tetrapropylammonium hydroxide solution (40 wt% mass fraction), 82.4 g of tetraethyl orthosilicate, 0.27 g of potassium chloride and 201.2 g of water were mixed in a hydrothermal kettle, and hydrolysis was carried out at 35°C with stirring for 6 h to obtain a mixed slurry;

[0107] S2, 0.15 g chloroplatinic acid was mixed with 1.23 g iron nitrate, 4.5 g ethylenediamine to obtain a mixed solution;

[0108] S3, the mixed solution in step S2 was added to the mixed slurry in step S1, after hydrothermal crystallization at 170°C for 96 h, centrifugation, washing, drying at 110°C for 12 h, and calcination at 560°C for 5 h in air atmosphere, a catalyst Cat3# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen was obtained.

[0109] The microcatalyst Cat3# was reduced under hydrogen atmosphere at 400°C for 4h. The average size of Pt metal clusters was about 0.9nm by electron microscopy analysis.

[0110] The catalyst Cat3# was used as catalyst for dehydrogenation reaction of perhydrodibenzyltoluene with hydrogen as carrier gas, as follows:

[0111] A fixed bed reactor was charged with 5g of catalyst Cat3#, and hydrogen was continuously fed into the reactor. The reactor was heated to 350°C and reduced for 3h. Then the temperature was kept constant, and the amount of H2 and perhydrodibenzyltoluene was adjusted. The molar ratio of perhydrodibenzyltoluene to hydrogen was 1:4, the pressure of the reactor was 0.1MPa, and the mass space velocity of perhydrodibenzyltoluene was 15h -1 The reaction product was obtained, and the product was analyzed online by gas chromatography.

[0112] Example 4

[0113] The catalyst composition of this example was 0.3wt% Pt, 0.6wt% K, 1.0wt% Sn, 1.0wt% Mn and 97.1wt% MFI molecular sieve (Silicalite-1 molecular sieve), which was recorded as catalyst Cat4#. The catalyst was prepared as follows:

[0114] S1, 81.2g of tetrapropylammonium hydroxide solution (40wt% in mass), 82.4g of tetraethyl orthosilicate, 0.27g of potassium chloride and 201.2g of water were mixed in an autoclave, and hydrolysis was carried out at 35°C for 6h under stirring to obtain a mixed slurry;

[0115] S2, 0.15g of chloroplatinic acid was mixed with 0.52g of tin tetrachloride, 0.59g of ammonium permanganate and 4.5g of ethylenediamine to obtain a mixed solution;

[0116] S3, the mixed solution in step S2 was added to the mixed slurry in step S1. After hydrothermal crystallization at 170°C for 96h, centrifugation, washing and drying at 110°C for 12h were carried out, and the catalyst Cat4# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen was obtained by calcination at 560°C for 5h in air atmosphere.

[0117] The microcatalyst Cat4# was reduced under hydrogen atmosphere at 400°C for 4h. The average size of Pt metal clusters was about 0.8nm by electron microscopy analysis.

[0118] The catalyst Cat4# was used as catalyst for dehydrogenation reaction of perhydrodibenzyltoluene with hydrogen as carrier gas, as follows:

[0119] A fixed bed reactor was charged with 5 g of catalyst Cat4#, and hydrogen was continuously fed into the reactor. The temperature was raised to 350°C and maintained for 3 h for reduction. Then, the temperature was kept constant, the H2 feed rate and the feed rate of perhydrodibenzyltoluene were adjusted, and the perhydrodibenzyltoluene and hydrogen were fed at a molar ratio of 1:4. The pressure in the reactor was 0.1 MPa, and the feed mass space velocity of perhydrodibenzyltoluene was 15 h-1. -1 The reaction product was obtained, and the product was analyzed online by gas chromatography.

[0120] Example 5

[0121] The catalyst used in this example had a composition of 0.4 wt% Rh, 0.8 wt% K, 1.2 wt% Sn, and 97.6 wt% MFI molecular sieve (Silicalite-1 molecular sieve), and was denoted as catalyst Cat5#. The catalyst was prepared according to the following steps:

[0122] S1, 81.2 g of tetrapropylammonium hydroxide solution (40 wt% by mass fraction), 82.4 g of tetraethyl orthosilicate, 0.36 g of potassium chloride, and 201.2 g of water were mixed in an autoclave, and hydrolysis was performed at 30°C for 8 h with stirring to obtain a mixed slurry;

[0123] S2, 0.19 g of rhodium trichloride was mixed with 0.62 g of tin tetrachloride and 4.5 g of ethylenediamine to obtain a mixed solution;

[0124] S3, the mixed solution in step S2 was added to the mixed slurry in step S1, and hydrothermal crystallization was performed at 190°C for 72 h. Then, centrifugation, washing, and drying at 120°C for 10 h were performed. Finally, calcination was performed at 580°C for 10 h in an air atmosphere to obtain the catalyst Cat5# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen.

[0125] A small amount of catalyst Cat5# was reduced at 400°C for 4 h in a hydrogen atmosphere. Electron microscopy analysis showed that the average size of Rh metal clusters was about 0.6 nm.

[0126] The catalyst Cat5# was used as the catalyst for dehydrogenation of perhydrodibenzyltoluene with hydrogen as the carrier gas. The specific conditions were as follows:

[0127] A fixed bed reactor was charged with 5 g of catalyst Cat5#, and hydrogen was continuously fed into the reactor. The temperature was raised to 380°C and maintained for 3 h for reduction. Then, the temperature was reduced to 360°C, the H2 feed rate and the feed rate of perhydrodibenzyltoluene were adjusted, and the perhydrodibenzyltoluene and hydrogen were fed at a molar ratio of 1:3. The pressure in the reactor was 0.15 MPa, and the feed mass space velocity of perhydrodibenzyltoluene was 10 h-1. -1 The reaction product was obtained, and the product was analyzed online by gas chromatography.

[0128] Example 6

[0129] The catalyst of this example has a composition of 0.4wt% Rh, 0.6wt% Cs, 1.0wt% Fe and 98.0wt% MFI molecular sieve (Silicalite-1 molecular sieve), and is denoted as catalyst Cat6#, which is prepared according to the following steps:

[0130] S1, 81.2g of tetrapropylammonium hydroxide solution (40wt% in mass fraction), 82.4g of tetraethyl orthosilicate, 0.18g of cesium chloride and 201.2g of water are mixed in an autoclave, and hydrolysis is carried out at 30°C under stirring for 10h to obtain a mixed slurry;

[0131] S2, 0.19g of rhodium trichloride is mixed with 1.03g of ferric nitrate and 4.5g of ethylenediamine to obtain a mixed solution;

[0132] S3, the mixed solution in step S2 is added to the mixed slurry in step S1, and after hydrothermal crystallization at 175°C for 72h, centrifugation, washing and drying at 110°C for 15h, calcination at 530°C for 10h in an air atmosphere is carried out to obtain the catalyst Cat6# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen.

[0133] A small amount of catalyst Cat6# is reduced at 400°C under a hydrogen atmosphere for 4h, and electron microscopy analysis shows that the average size of Rh metal clusters is about 0.8nm.

[0134] The catalyst Cat6# is used as a catalyst for dehydrogenation reaction of perhydrodibenzyltoluene with hydrogen as a carrier gas, and the specific process is as follows:

[0135] A fixed bed reactor containing 5g of catalyst Cat6# is continuously fed with hydrogen, heated to 400°C for reduction for 2h, then cooled to 350°C, and the H2 feed amount and the perhydrodibenzyltoluene feed amount are adjusted, and the molar ratio of perhydrodibenzyltoluene to hydrogen is 1:5, the pressure of the reactor is 0.1MPa, and the mass space velocity of perhydrodibenzyltoluene is 12h -1 , and the reaction product is obtained, which is analyzed online by gas chromatography.

[0136] Example 7

[0137] The catalyst of this example has a composition of 0.25wt% Pt, 0.5wt% Cs, 0.8wt% Ge and 98.45wt% MFI molecular sieve (Silicalite-1 molecular sieve), and is denoted as catalyst Cat7#, which is prepared according to the following steps:

[0138] S1, 81.2g of tetrapropylammonium hydroxide solution (40wt% in mass fraction), 82.4g of tetraethyl orthosilicate, 1.5g of cesium chloride and 201.2g of water are mixed in an autoclave, and hydrolysis is carried out at 35°C under stirring for 6h to obtain a mixed slurry;

[0139] S2, 0.12 g chloroplatinic acid was mixed with 0.56 g germanium tetrachloride, 4.5 g ethylenediamine to obtain a mixed solution;

[0140] S3, the mixed solution in step S2 was added to the mixed slurry in step S1, and after hydrothermal crystallization at 180℃ for 72 h, centrifugation, washing, drying at 120℃ for 8 h, and calcination at 550℃ for 8 h in air atmosphere, a catalyst Cat7# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen was obtained.

[0141] A small amount of catalyst Cat7# was reduced at 400℃ for 4 h in a hydrogen atmosphere, and electron microscopy analysis showed that the average size of Pt metal clusters was about 0.8 nm.

[0142] The catalyst Cat7# was used as a catalyst for dehydrogenation reaction of perhydrodibenzyltoluene with hydrogen as a carrier gas, as follows:

[0143] A fixed bed reactor containing 5 g of catalyst Cat7# was continuously fed with hydrogen, heated to 360℃ for 2 h, then cooled to 350℃, and the H2 feed rate and the perhydrodibenzyltoluene feed rate were adjusted to a molar ratio of perhydrodibenzyltoluene to hydrogen of 1:5, the reactor pressure was 0.15 MPa, and the perhydrodibenzyltoluene feed mass space velocity was 12 h -1 , to obtain a reaction product, which was analyzed online by gas chromatography.

[0144] Example 8

[0145] The catalyst composition of this example was 0.3 wt% Pt, 0.6 wt% K, 1.0 wt% Sn, 1.2 wt% Fe, and 96.9 wt% MFI molecular sieve (TS-1-a molecular sieve with Ti content of 2.0 wt%), denoted as catalyst Cat8#, which was prepared as follows:

[0146] S1, 81.2 g of tetrapropylammonium hydroxide solution (40 wt% mass fraction), 82.4 g of tetraethyl orthosilicate, 0.27 g of potassium chloride, and 201.2 g of water were mixed in a hydrothermal kettle, and hydrolysis was carried out at 35℃ with stirring for 6 h to obtain a mixed slurry 1; 3.36 g of tetrabutyl titanate and 39.28 g of isopropanol were stirred at room temperature for 1 h to obtain a mixed slurry 2; then the mixed slurry 1 and the mixed slurry 2 were mixed and stirred for 1 h to obtain a mixed slurry;

[0147] S2, 0.15 g of chloroplatinic acid was mixed with 0.52 g of tin tetrachloride, 1.23 g of iron nitrate, and 4.5 g of ethylenediamine to obtain a mixed solution;

[0148] S3, the mixed solution in step S2 is added to the mixed slurry in step S1, after hydrothermal crystallization at 170°C for 96h, centrifugation, washing, drying at 110°C for 12h, and calcination at 560°C for 5h in air atmosphere, a catalyst Cat8# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen gas is obtained.

[0149] A small amount of catalyst Cat8# is reduced at 400°C for 4h in a hydrogen atmosphere, and electron microscopy analysis shows that the average size of Pt metal clusters is about 0.7nm.

[0150] The catalyst Cat8# is used as a catalyst for dehydrogenation of perhydrodibenzyltoluene with hydrogen as a carrier gas, and the dehydrogenation reaction is carried out as follows:

[0151] A fixed bed reactor containing 5g of catalyst Cat8# is continuously fed with hydrogen, heated to 350°C for 3h, and then the temperature is kept constant. The H2 feed amount and the perhydrodibenzyltoluene feed amount are adjusted, and the molar ratio of perhydrodibenzyltoluene to hydrogen is 1:4. The pressure of the reactor is 0.1MPa, and the perhydrodibenzyltoluene feed mass space velocity is 15h -1 The reaction product is obtained, and the product is analyzed online by gas chromatography.

[0152] Example 9

[0153] The catalyst composition of this example is 0.3wt% Pt, 0.6wt% K, 1.0wt% Sn, 1.2wt% Fe, and 96.9wt% MFI molecular sieve (TS-1-b molecular sieve with Ti content of 1.3wt%), which is denoted as catalyst Cat9#, and is prepared as follows:

[0154] S1, 81.2g of tetrapropylammonium hydroxide solution (40wt% by mass), 82.4g of tetraethyl orthosilicate, 0.27g of potassium chloride, and 201.2g of water are mixed in a hydrothermal kettle, and hydrolysis is carried out at 35°C for 6h with stirring to obtain a mixed slurry 1; 2.24g of tetrabutyl titanate and 39.28g of isopropanol are stirred at room temperature for 1h to obtain a mixed slurry 2; then the mixed slurry 1 and the mixed slurry 2 are mixed and stirred for 1h to obtain a mixed slurry;

[0155] S2, 0.15g of chloroplatinic acid is mixed with 0.52g of tin tetrachloride, 1.23g of iron nitrate, and 4.5g of ethylenediamine to obtain a mixed solution;

[0156] S3, the mixed solution in step S2 is added to the mixed slurry in step S1, after hydrothermal crystallization at 170°C for 96h, centrifugation, washing, drying at 110°C for 12h, and calcination at 560°C for 5h in air atmosphere, a catalyst Cat9# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen gas is obtained.

[0157] A small amount of catalyst Cat9# was reduced under hydrogen atmosphere at 400°C for 4h. The average size of Pt metal clusters was about 0.7nm by electron microscopy analysis.

[0158] Catalyst Cat9# was used as catalyst for dehydrogenation reaction of perhydrodibenzyltoluene with hydrogen as carrier gas, as follows:

[0159] A fixed bed reactor was charged with 5g of catalyst Cat9#, and hydrogen was continuously fed into the reactor. The temperature was raised to 350°C and the reduction was carried out for 3h. Then the temperature was kept constant, and the amount of hydrogen and perhydrodibenzyltoluene was adjusted. The molar ratio of perhydrodibenzyltoluene to hydrogen was 1:4, the pressure of the reactor was 0.1MPa, and the mass space velocity of perhydrodibenzyltoluene was 15h -1 The reaction product was obtained, and the product was analyzed online by gas chromatography.

[0160] Example 10

[0161] The catalyst of this example was composed of 0.3wt% Pt, 0.6wt% K, 1.0wt% Sn, 1.2wt% Fe and 96.9wt% MFI molecular sieve (ZSM-5-a molecular sieve with Al content of 1.0wt%), and was recorded as catalyst Cat10#. It was prepared as follows:

[0162] S1, 81.2g of tetrapropylammonium hydroxide solution (40wt% in mass), 82.4g of tetraethyl orthosilicate, 0.27g of potassium chloride and 201.2g of water were mixed in an autoclave, and hydrolysis was carried out at 35°C for 6h under stirring to obtain a mixed slurry 1. Then, 2.45g of aluminum nitrate was added to the mixed slurry 1 and stirred for 1h to obtain a mixed slurry 2;

[0163] S2, 0.15g of chloroplatinic acid was mixed with 0.52g of tin tetrachloride, 1.23g of iron nitrate and 4.5g of ethylenediamine to obtain a mixed solution;

[0164] S3, the mixed solution in step S2 was added to the mixed slurry 2 in step S1. After hydrothermal crystallization at 170°C for 96h, centrifugation, washing and drying at 110°C for 12h were carried out, and then calcination was carried out at 560°C for 5h under air atmosphere to obtain catalyst Cat10# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen.

[0165] A small amount of catalyst Cat10# was reduced under hydrogen atmosphere at 400°C for 4h. The average size of Pt metal clusters was about 0.6nm by electron microscopy analysis.

[0166] Catalyst Cat10# was used as catalyst for dehydrogenation reaction of perhydrodibenzyltoluene with hydrogen as carrier gas, as follows:

[0167] Hydrogen was continuously introduced into a fixed-bed reactor containing 5g of Cat10# catalyst, and the reactor was heated to 350℃ for reduction for 3 hours. The temperature was then maintained constant, and the feed rates of H2 and perhydrodibenzyltoluene were adjusted to a molar ratio of 1:4 (perhydrodibenzyltoluene to hydrogen). The reactor pressure was 0.1 MPa, and the feed mass hourly space velocity (WHSV) of perhydrodibenzyltoluene was 15 h⁻¹. -1 The reaction products were obtained and analyzed online by gas chromatography.

[0168] Examples 11-16

[0169] The difference between Examples 11-12 and Example 2 is that the mass percentage of Pt was adjusted. The catalysts prepared are shown in Table 1 below.

[0170] The difference between Examples 13-14 and Example 2 is that the mass percentage of K was adjusted, and the catalysts prepared are shown in Table 1 below.

[0171] The difference between Examples 15-16 and Example 2 is that the mass percentage of Sn and Fe was adjusted. The catalysts prepared are shown in Table 1 below.

[0172] Comparative Example 1

[0173] The catalyst in this embodiment consists of 0.3 wt% Pt and 99.7 wt% MFI molecular sieve (Silicalite-1 molecular sieve), denoted as catalyst comparative example Cat1#, and was prepared according to the following steps:

[0174] S1. Mix 81.2g of tetrapropylammonium hydroxide solution (40wt%), 82.4g of tetraethyl orthosilicate and 201.2g of water in a hydrothermal reactor and hydrolyze at 35°C for 6 hours with stirring to obtain a mixed slurry.

[0175] S2. Mix 0.15g of chloroplatinic acid and 4.5g of ethylenediamine to obtain a mixed solution;

[0176] S3. Add the mixed solution from step S2 to the mixed slurry from step S1, perform hydrothermal crystallization at 170°C for 96 hours, centrifuge and wash, dry at 110°C for 12 hours, and calcine at 560°C for 5 hours in air atmosphere to obtain the comparative catalyst Cat1# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen.

[0177] A trace amount of catalyst, comparative example Cat1#, was reduced at 400℃ for 4 hours in a hydrogen atmosphere. Electron microscopy analysis showed that the average size of the Pt clusters was approximately 2.4 nm.

[0178] Using Catalyst Comparative Example Cat1# as the catalyst, a dehydrogenation reaction was carried out with perhydrodibenzyltoluene as the raw material and hydrogen as the carrier gas, as detailed below:

[0179] A fixed bed reactor was charged with 5 g of the catalyst Comparative Example Cat1#, and hydrogen was continuously fed into the reactor. The reactor was heated to 350°C and reduced for 3 h, and then the temperature was kept constant. The H2 feed amount and the feed amount of perhydrodibenzyltoluene were adjusted so that the molar ratio of perhydrodibenzyltoluene to hydrogen was 1:4. The pressure of the reactor was 0.1 MPa, and the feed mass space velocity of perhydrodibenzyltoluene was 15 h-1. -1 The reaction product was obtained, and the product was analyzed online by gas chromatography.

[0180] Comparative Example 2

[0181] The catalyst of this example had a composition of 0.4 wt% Rh and 99.6 wt% MFI molecular sieve (Silicalite-1 molecular sieve), denoted as Comparative Example Cat2#, and was prepared according to the following steps:

[0182] S1, 81.2 g of tetrapropylammonium hydroxide solution (40 wt% by mass fraction), 82.4 g of tetraethyl orthosilicate, and 201.2 g of water were mixed in an autoclave, and hydrolysis was performed at 30°C for 8 h with stirring to obtain a mixed slurry;

[0183] S2, 0.19 g of rhodium trichloride and 4.5 g of ethylenediamine were mixed to obtain a mixed solution;

[0184] S3, the mixed solution in step S2 was added to the mixed slurry in step S1, and hydrothermal crystallization was performed at 190°C for 72 h. Then, centrifugation, washing, and drying at 120°C for 10 h were performed, and calcination was performed at 580°C for 10 h in an air atmosphere to obtain the catalyst Comparative Example Cat2# for dehydrogenation of perhydrodibenzyltoluene to produce hydrogen.

[0185] A small amount of the catalyst Comparative Example Cat2# was reduced at 400°C for 4 h in a hydrogen atmosphere, and electron microscopy analysis showed that the average size of Rh clusters was about 2.3 nm.

[0186] The catalyst Comparative Example Cat2# was used as a catalyst, and dehydrogenation was performed using perhydrodibenzyltoluene as a raw material and hydrogen as a carrier gas, as follows:

[0187] A fixed bed reactor was charged with 5 g of the catalyst Comparative Example Cat2#, and hydrogen was continuously fed into the reactor. The reactor was heated to 380°C and reduced for 3 h, and then the temperature was reduced to 360°C. The H2 feed amount and the feed amount of perhydrodibenzyltoluene were adjusted so that the molar ratio of perhydrodibenzyltoluene to hydrogen was 1:3. The pressure of the reactor was 0.15 MPa, and the feed mass space velocity of perhydrodibenzyltoluene was 10 h-1. -1 The reaction product was obtained, and the product was analyzed online by gas chromatography.

[0188] Test method

[0189] 1. Method for detecting perhydrodibenzyltoluene and dibenzyltoluene

[0190] Gaseous product detection method:

[0191] Injection volume: 250 μL; column temperature: 40 °C for 3 min, ramp to 190 °C at 5 °C / min, hold for 10 min; injector temperature 250 °C; detector temperature: 300 °C.

[0192] Split injection at the injector, split ratio 10:1; septum purge flow rate: 3 mL / min; column 1 (3 Ft 1 / 8 2 mm HayeSep Q 80 / 100 UM + 6 Ft 1 / 8 2 mm HayeSep Q 80 / 100 UM + 8 Ft 1 / 8 2 mm MoiSieve 5A 60 / 80 LM) flow rate (He): 25 mL / min; column 2 (HP-AL / S) flow rate (N2): 5 mL / min; column 3 (HP-INNOWAX) flow rate (N2): 2 mL / min.

[0193] Front detector FID and back detector FID hydrogen flow rate: 30 mL / min; air flow rate: 400 mL / min; tail gas purge flow rate: 25 mL / min. Auxiliary detector TCD reference flow rate: 40 mL / min; tail gas purge flow rate: 5 mL / min.

[0194] Liquid product detection method:

[0195] Injection volume: 250 μL; column temperature: 40 °C for 3 min, ramp to 300 °C at 5 °C / min, hold for 60 min; injector temperature 300 °C; detector temperature: 300 °C.

[0196] Split injection at the injector, split ratio 19:1; septum purge flow rate: 3 mL / min; column (HP-5) flow rate (N2): 1 mL / min

[0197] Detector FID hydrogen flow rate: 30 mL / min; air flow rate: 400 mL / min; tail gas purge flow rate: 25 mL / min.

[0198] 2. Method for detecting the composition of the catalyst

[0199] About 0.02 g of the metal molecular sieve sample was accurately weighed using a precision electronic balance under a dust-free environment, and then the weighed sample was placed into a polytetrafluoroethylene beaker and 1 mL of a solution formed by mixing hydrofluoric acid and aqua regia at a ratio of 1 : 1 was added. Subsequently, the beaker was placed in an 80°C oil bath and 10 mL of deionized water was added for continuous stirring for 6 h to complete the digestion. After the digestion was completed and completely cooled, the solution was transferred to a 50 mL volumetric flask. The solution was diluted to the marked calibration line with deionized water, and the diluted solution was used for ICP-OES (inductively coupled plasma optical emission spectrometry) detection.

[0200] 3. Method for detecting the size of metal clusters

[0201] The sample powder was first dispersed in ethanol by ultrasonic and deposited on a copper grid coated with an ultrathin porous carbon film. Subsequently, the HAADF-STEM image of the metal molecular sieve sample was collected using a JEOL-2100F instrument at 200 kV.

[0202] 4. XRD test

[0203] The crystal structure of the powder sample was characterized using a Rigaku Smartlab 9kW X-ray diffractometer equipped with Cu Ka radiation. The powder sample was uniformly laid on the sample tray of the XRD instrument, and scanning was performed at a change rate of 10 degrees per minute to obtain the X-ray diffraction pattern of the catalyst. Before scanning, the powder sample was reduced at 350°C for 3 h.

[0204] Test results

[0205] Table 1. Reaction results of catalysts in a fixed bed reactor for catalyzing the dehydrogenation of perhydrodibenzyltoluene

[0206]

[0207] As can be seen from the data of Examples 1-16 in Table 1, the catalysts provided by the application are suitable for the dehydrogenation reaction of perhydrodibenzyltoluene, and have the advantages of high catalytic activity, high selectivity and high stability, etc. The possible reasons are as follows: the introduction of alkali metals such as K and Cs can regulate the ionic radius, charge effect and surface energy of the active components such as Rh and Pt, promote the high dispersion of the active components, so that a small amount of active components can expose a larger active surface area, thereby improving the catalytic activity, and the alkali metals such as K and Cs have high chemical stability, which can remain stable at high temperature and reaction atmosphere, thereby enhancing the overall stability and service life of the catalyst; secondly, the introduction of second metal promoters such as Sn, Ge, Fe and Mn can adjust the electronic structure, reactivity and lattice constant of the surface of the active component, for example, Sn can provide electrons to the active component Rh, Pt, which changes the surface electronic structure of the active component Rh, Pt through electronic effect and geometric effect, thereby improving the catalytic activity, and Fe improves the desorption of dibenzyltoluene, thereby improving the catalytic selectivity; thirdly, the molecular sieve carrier provided by the application stabilizes the metal cluster in the pore and the outer surface of the molecular sieve carrier through the action of physical confinement, the particle size of the metal cluster is less than 1 nm, the specific surface area is larger, which can provide more active sites, thereby increasing the contact area of the catalyst and the reactants, and further improving the catalytic efficiency.

[0208] As can be seen from the comparison of the data of Example 1 and Example 2 in Table 1, the simultaneous introduction of Fe and Sn can further improve the activity, selectivity and stability of the catalyst. The possible reasons are as follows: the simultaneous introduction of Fe and Sn can form stable multi-metal clusters with the active components such as Rh and Pt, producing a synergistic effect, specifically, the adjacency of Sn, Fe and Pt at the atomic level allows the construction of multifunctional active sites for effective C-H bond activation, which promotes the progress of the catalytic reaction, thereby exhibiting excellent catalytic activity.

[0209] As can be seen from the comparison of the data of Example 2 and Examples 8-10 in Table 1, among the optional types of molecular sieve carriers, Silicalite-1 has better catalytic activity, selectivity and stability, etc. The possible reasons are as follows: the specific pore structure and surface acidity of Silicalite-1 provide a more optimal environment for the catalytic reaction.

[0210] As can be seen from the comparison of the data of Example 2 and Examples 11-16 in Table 1, when the mass percentage content of the noble metal active component is controlled to be in the range of 0.3% to 0.4%, the mass percentage content of the first metal promoter is controlled to be in the range of 0.6% to 0.8%, and the mass percentage content of the second metal promoter is controlled to be in the range of 1.0% to 2.2%, the activity, selectivity and stability of the catalyst can be further improved. The possible reason is that, within the appropriate range, the first metal promoter and the second metal promoter can better cooperate to adjust the dispersion and electronic effect of the noble metal active component, thereby improving the catalytic activity, selectivity and stability of the catalyst.

[0211] Although illustrative embodiments have been shown and described, it is to be understood that the above-described embodiments are not be construed as limiting, and that changes, alternatives and modifications can be suggested as being apparent to one skilled in the art without departing from the spirit, principles and scope of the application.

Claims

1. A catalyst for the dehydrogenation of perhydrodibenzyltoluene, characterized in that, The catalyst comprises a first metal promoter, a metal cluster, and a molecular sieve support, wherein the metal cluster comprises a noble metal active component and a second metal promoter; The first metal additive and the metal clusters are distributed on the molecular sieve support; The particle size of the metal clusters is less than 1 nm.

2. The catalyst according to claim 1, wherein, Based on the mass of the catalyst The mass percentage of the noble metal active component is 0.05% to 0.5%; and / or, The first metal additive has a mass percentage content of 0.05% to 1.0%; and / or, The second metal additive has a mass percentage content of 0.1% to 3.0%; and / or, The molecular sieve carrier has a mass percentage content of 95.5% to 99.8%.

3. The catalyst according to claim 2, wherein, Based on the mass of the catalyst The mass percentage of the noble metal active component is 0.3% to 0.4%; and / or, The first metal additive has a mass percentage content of 0.6% to 0.8%; and / or, The second metal additive has a mass percentage content of 1.0% to 2.2%; and / or, The molecular sieve carrier has a mass percentage content of 96.6% to 98.1%.

4. The catalyst according to claim 1, wherein, The average particle size of the metal clusters is 0.6 nm to 0.9 nm.

5. The catalyst according to any one of claims 1 to 4, wherein, The catalyst satisfies at least one of the following conditions: (1) The noble metal active component includes one or more of Rh and Pt; (2) The first metal additive includes one or more of K, Rb and Cs; (3) The second metal additive includes one or more of Sn, Ge, Fe and Mn; (4) The molecular sieve carrier includes a molecular sieve carrier composed of all-silicon or high-silicon materials with an MFI topology.

6. The catalyst according to claim 5, wherein, The molecular sieve support includes one or more of Silicalite-1, ZSM-5, and TS-1.

7. The method for preparing the catalyst according to any one of claims 1 to 6, characterized in that, The preparation method includes: S1. Mix the molecular sieve template agent, silicon source, and water-soluble compound of the first metal additive with water, and hydrolyze to obtain a mixed slurry; S2. Mix the water-soluble compound of the noble metal active component, the water-soluble metal salt of the second metal auxiliary, and ethylenediamine to obtain a mixed solution; S3. The mixed solution obtained in step S2 is mixed with the mixed slurry obtained in step S1, and after hydrothermal crystallization treatment, it is centrifuged, washed, dried and calcined to obtain the catalyst.

8. The preparation method according to claim 7, wherein, The preparation method satisfies at least one of the following conditions: (1) The molecular sieve template agent includes one or more of tetrapropylammonium hydroxide, tetraethylammonium hydroxide and tetramethylammonium hydroxide; (2) The silicon source includes one or more of tetramethyl orthosilicate, tetraethyl orthosilicate, silica sol, sodium silicate and tetrabutyl orthosilicate; (3) The water-soluble compound of the first metal auxiliary includes one or more of KCl, KNO3, K2SO4, KOH, RbCl, RbNO3, CsCl and CsNO3; (4) The water-soluble compounds of the noble metal active components include one or more of chloroplatinic acid, ammonium hexachloroplatinate, platinum chloride, rhodium trichloride, rhodium nitrate and ammonium pentachlororhodium hydrate; (5) The water-soluble metal salt of the second metal additive includes one or more of tin tetrachloride, stannous chloride, stannous nitrate, stannous sulfate, germanium tetrachloride, ammonium germanate, germanium nitrate, ferric chloride, ferric sulfate, ferric nitrate, potassium permanganate, and ammonium permanganate. (6) In step S1, the hydrolysis conditions are: stirring at 30-50°C for 3-12 hours; (7) In step S3, the conditions for the hydrothermal crystallization treatment are: to be carried out at 150-200°C for 24-144 hours; (8) In step S3, the drying conditions are: 8 to 24 hours at 90 to 130°C; (9) In step S3, the calcination conditions are: under an air atmosphere, at 450-700°C for 2-15 hours; (10) In step S2, the mass ratio of the water-soluble compound of the active component to ethylenediamine is 1:(2-50).

9. The application of the catalyst according to any one of claims 1 to 6 or the catalyst prepared by the preparation method according to any one of claims 7 to 8 in the dehydrogenation reaction of perhydrodibenzyltoluene, characterized in that, During the dehydrogenation process, the reaction temperature is 300–500℃, the reaction pressure is 0.1–1.0 MPa, and the mass hourly space velocity (HHSV) of the perhydrodibenzyltoluene feed is 5–50 h⁻¹. -1 The carrier gas is hydrogen and / or nitrogen, and the feed molar ratio of the carrier gas to the perhydrodibenzyltoluene is (2-10):

1.

10. The application according to claim 9, characterized in that, Before carrying out the dehydrogenation process, the catalyst is first reduced in a hydrogen atmosphere; during the reduction process, the reduction temperature is 300-500℃ and the reduction time is 1-5h.

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