Hydrogen storage catalytic composite material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of crossing of advanced energy materials and green catalysis technologies, and relates to a hydrogen storage catalytic composite material as well as a preparation method and application thereof. The hydrogen storage catalytic composite material is formed by compounding a solid hydrogen storage material and a supported catalyst according to a mass ratio of (1-3), the solid hydrogen storage material is MgH2 particles and LaNi5 particles; the supported catalyst comprises a carrier and active components supported inside and on the surface of the carrier, the carrier comprises one of Al2O3, SiO2, activated carbon and a molecular sieve, and the active components are one or more of Ni, W, Mo, Co, Pd and Pt. A close contact interface is formed between the two materials through ball milling, hydrogen atoms released by the hydrogen storage material at the reaction temperature rapidly overflow to the surface of the catalyst through the interface, continuous active hydrogen is provided for the hydrogenation reaction, mass transfer limitations such as hydrogen dissolution and diffusion in a traditional system are avoided, and a local hydrogen-rich environment is created.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of advanced energy materials and green catalytic technology, and particularly relates to a hydrogen storage catalytic composite material and a preparation method and application thereof. BACKGROUND

[0002] Catalytic hydrogenation is a chemical reaction process in which hydrogen (H2) molecules are activated and added to unsaturated organic compounds (such as olefins, aromatic hydrocarbons, etc.) under the action of a catalyst, in order to increase the hydrogen-carbon ratio of the raw material, reduce the unsaturation, and thus achieve the purpose of refining, upgrading or synthesizing specific chemicals. The hydrogenation of condensed ring aromatic hydrocarbons (such as anthracene, etc.) is a key step in the production of high-value chemicals. However, the traditional catalytic hydrogenation process usually needs to be carried out at high temperature (usually higher than 300°C) and high pressure (usually higher than 3 MPa, and even up to 20 MPa), in order to overcome the kinetic barrier and thermodynamic equilibrium limit. This results in huge energy consumption, high equipment investment and potential safety risks.

[0003] The efficiency and economic benefit of catalytic hydrogenation directly depend on the performance of the catalyst. Supported catalysts are a kind of heterogeneous catalysts in which active components (such as Ni, Mo, Co, etc. metals) are supported on the surface or inside the pores of a carrier (such as alumina (Al2O3), silica (SiO2), etc.) by a specific method. They are widely used in various hydrogenation reactions due to their high specific surface area and controllable active centers. However, their catalytic efficiency is still limited by the mass transfer efficiency of hydrogen in the reaction system, the generation rate of active hydrogen, and the hydrogen concentration on the surface of the catalyst. In order to overcome the above limitations, it is often necessary to use harsh reaction conditions of high temperature and high pressure to forcibly improve the mass transfer and activation efficiency of hydrogen, which inevitably leads to high energy consumption, large equipment investment and increased safety risks. SUMMARY

[0004] The purpose of the present application is to provide a hydrogen storage catalytic composite material and a preparation method and application thereof, so as to overcome the deficiencies of the prior art, and to realize efficient hydrogen overflow, significantly reduce the hydrogenation reaction conditions and improve the reaction efficiency by mechanical ball milling under the atmosphere of inert / hydrogen-argon mixed gas to construct a solid hydrogen storage material and a catalyst (supported) composite material, and applying it to the hydrogenation conversion of condensed ring aromatic hydrocarbons.

[0005] In order to achieve the above purpose, the technical scheme of the present application is as follows: In a first aspect, the present application provides a hydrogen storage catalytic composite material, which is composed of a solid hydrogen storage material and a supported catalyst; The mass ratio of the solid hydrogen storage material to the supported catalyst is (1-3): 1; The solid hydrogen storage material is MgH2 particles and LaNi5 particles; The supported catalyst comprises a carrier and active components supported on the carrier, the carrier comprises one or more of Al2O3, SiO2, activated carbon and molecular sieve, and the active components are one or more of Ni, W, Mo, Co, Pd and Pt.

[0006] The solid hydrogen storage material is a functional material capable of reversibly absorbing and releasing hydrogen under specific conditions, such as magnesium-based hydrogen storage material (e.g., MgH2) and rare earth-based hydrogen storage alloy (e.g., AB5 type LaNi5), which can reversibly absorb and release hydrogen under mild conditions. Traditionally, the research and application of such materials are mainly concentrated in the field of hydrogen storage and transportation. By mixing the supported catalyst and the solid hydrogen storage material through ball milling, the characteristics of the solid hydrogen storage material in releasing hydrogen under reaction conditions are utilized to provide a high concentration of active hydrogen near the active sites of the catalyst in situ, thereby getting rid of the dependence on external high-pressure hydrogen and realizing efficient hydrogenation under milder conditions. The present application forms a large and tight contact interface between the two materials through ball milling. The hydrogen atoms released by the hydrogen storage material at the reaction temperature can quickly "overflow" to the surface of the catalyst through the interface, thereby providing a continuous supply of active hydrogen species for the hydrogenation reaction, avoiding the mass transfer limitations such as hydrogen dissolution and diffusion in the traditional system, and creating a local hydrogen-rich environment.

[0007] In some other embodiments, the mass ratio of the solid hydrogen storage material to the supported catalyst is 2:1. The solid hydrogen storage material is MgH2 particles; the carrier of the supported catalyst is one of Al2O3 and SiO2, and the active component is Ni and W.

[0008] The solid hydrogen storage material, particularly the magnesium-based hydrogen storage material (e.g., MgH2), can reversibly absorb and release hydrogen under mild conditions, and is introduced into the catalytic reaction to utilize its "hydrogen pump" characteristics to provide active hydrogen in situ for the reaction, so as to reduce the harshness of the reaction conditions.

[0009] In some other embodiments, the loading amount of the active component in the supported catalyst is 25-35%, and the mass ratio of Ni to W is (1.5-2.5):1. The particle size of the hydrogen storage catalytic composite material is 110 nm-3 μm.

[0010] Specifically, the loading amount of the active component in the supported catalyst is 30%, and the mass ratio of Ni to W is 2:1.

[0011] In a second aspect, the present application provides a preparation method of the hydrogen storage catalytic composite material of the first aspect, comprising the following steps: The solid hydrogen storage material, the supported catalyst and the ball milling aid are mixed to obtain a mixture; and the mixture is ball milled in an argon-hydrogen mixed gas (5% hydrogen and 95% argon) atmosphere to obtain the hydrogen storage catalytic composite material. The ball milling ball-to-material ratio is (10-20):1, the ball milling rotation speed is 300-500 rpm, and the ball milling time is 1-5 h.

[0012] Specifically, the ball milling ball-to-material ratio is 10:1, 15:1 or 20:1, the ball milling rotation speed is 300 rpm, 400 rpm or 500 rpm, and the ball milling time is 1 h, 2 h, 3 h, 4 h or 5 h.

[0013] The present application uses high-energy ball milling technology to composite and fluidize the solid hydrogen storage particles and the supported catalyst in a nanoscale by using tetrahydrofuran (THF) or cyclohexane as a ball milling aid, so as to construct a compact "hydrogen storage-catalysis" micro-reaction interface. The composite system not only uses the hydrogen storage material as an additional hydrogen source, but more importantly, the compact interface formed in the ball milling process greatly promotes the hydrogen overflow effect, that is, the hydrogen atoms quickly migrate from the surface of the hydrogen storage material to the active centers of the catalyst, so as to create a local high-concentration active hydrogen environment on the surface of the catalyst, which can significantly accelerate the hydrogenation reaction kinetics.

[0014] In some other embodiments, the ball milling aid is one of tetrahydrofuran and cyclohexane. The mass ratio of the solid hydrogen storage material to the supported catalyst is (1-3):1. The solid hydrogen storage material is MgH2 particles, and the supported catalyst is a nickel-tungsten catalyst. The inert atmosphere is a hydrogen-argon mixed gas, which is air-tight to avoid oxidation of the active powder generated by high-energy collision in the ball milling.

[0015] In a third aspect, the present application provides an application of the hydrogen storage catalytic composite material in the first aspect in a hydrogenation reaction of a condensed aromatic hydrocarbon.

[0016] In a fourth aspect, the present application provides a method for a hydrogenation reaction of a condensed aromatic hydrocarbon, which uses the hydrogen storage catalytic composite material in the first aspect as a catalyst and includes the following steps: The hydrogen storage catalytic composite material and the condensed aromatic hydrocarbon are added into a reaction kettle, air is excluded, and hydrogen is filled to perform a hydrogenation reaction.

[0017] The hydrogen storage material acts as a dynamic "hydrogen pool" in the reaction system, which can smooth the hydrogen concentration fluctuation in the reaction process, stabilize the hydrogenation performance of the catalyst, and prevent the catalyst from being deactivated or carbonized due to local hydrogen deficiency.

[0018] In some other embodiments, the condensed aromatic hydrocarbon is one of anthracene, phenanthrene, pyrene, benzpyrene, heavy crude oil, atmospheric residue and vacuum residue. The mixing mass ratio of the hydrogen storage catalytic composite material to the raw material containing the condensed ring aromatic hydrocarbon is (0.5~2.5):1.

[0019] In some other embodiments, the initial pressure of the hydrogenation reaction is 0.1~3 MPa, the reaction temperature is 250~320 ℃, and the reaction time is 1~5h.

[0020] In some other embodiments, the condensed ring aromatic hydrocarbon is anthracene; The mixing mass ratio of the hydrogen storage catalytic composite material to the raw material containing the condensed ring aromatic hydrocarbon is (2~2.5):1; The initial pressure of the hydrogenation reaction is 1~3 MPa, the reaction temperature is 280~300 ℃, and the reaction time is 2~4h.

[0021] The beneficial effects of the present application are: (1) The present application builds a close interface contact between the hydrogen storage material and the catalyst through hydrogenation and ball milling process, so that the hydrogen storage material acts as an "in-situ hydrogen pump" to continuously release active hydrogen atoms in the reaction and quickly overflow to the catalyst active center through the interface, creating a local high-concentration active hydrogen environment. It effectively breaks through the mass transfer limitations such as hydrogen dissolution and diffusion in traditional processes, becoming the key to improving reaction kinetics. At the same time, the hydrogen storage material can act as a dynamic "hydrogen pool" to smooth the hydrogen concentration fluctuations in the reaction process, stably supplying hydrogen to the catalyst active sites. It effectively prevents the deactivation and carbon deposition of the catalyst caused by local transient hydrogen deficiency, and improves the operation stability and service life of the system.

[0022] (2) The ball milling process route adopted by the present application is mature, universal, green and easy to scale up, and has good industrialization prospects. It is expected to be widely used in heavy oil processing, coal tar deep processing and other fields that require efficient hydrogenation, and provides a new solution for developing a new generation of mild, efficient and safe catalytic hydrogenation technology.

[0023] (3) The hydrogen storage catalytic composite material prepared by the present application has a hydrogenation conversion rate of anthracene, a typical condensed ring aromatic hydrocarbon, as high as 93.9% under the optimized conditions of 300 °C and 2 MPa, which is much higher than the conversion rate (25.6%) of a single catalyst system under the same conditions. This proves that the compounding is not a simple superposition of functions, but significantly improves the intrinsic catalytic efficiency through interface synergy. It can achieve efficient conversion under milder conditions. The conversion rate of anthracene can still remain at a high level of 98.7% and 98.4% respectively under the conditions of 280 °C (reduced by 20 °C) and 1 MPa (pressure reduced by 50%). This "temperature reduction and efficiency increase, pressure reduction and high efficiency" feature overturns the traditional catalytic mode of relying on the strengthening of reaction intensity to intensify the process, and fundamentally reduces energy consumption, equipment requirements and safety risks. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The embodiments of the application, and their

[0025] Figure 1 X-ray powder diffraction pattern of the tested material, magnesium hydride solid hydrogen storage powder in the comparative example 2 of the present application; Figure 2 X-ray powder diffraction pattern of the tested material in the example 1 and comparative example 1 of the present application; Figure 3 Scanning electron microscope image of the tested commercial nickel tungsten catalyst in the comparative example 1 of the present application; Figure 4 Scanning electron microscope image of the tested material, magnesium hydride solid hydrogen storage powder in the comparative example 2 of the present application; Figure 5 Scanning electron microscope image of the tested material, magnesium hydride solid hydrogen storage powder in the comparative example 2 of the present application; Figure 6 Schematic diagram of hydrogen overflow effect in the example 1 of the present application; Figure 7 Schematic diagram of hydrogen overflow effect in the example 1 of the present application; DETAILED DESCRIPTION

[0026] Those skilled in the art will appreciate that the following examples are intended to be illustrative only and are not intended to limit the scope of the present application. Unless otherwise indicated, conventional conditions are used in the examples, or the conditions recommended by the manufacturer are used. Where the manufacturer of a component is not indicated, a conventional product available from a commercial vendor is used. In the examples, the type of supported catalyst is not specifically limited, and any commonly used supported catalyst can be used, and a commercial nickel tungsten catalyst is used in the examples, which can be selected from Shandong Gaodelutian Catalyst Co., Ltd.

[0027] In view of the problems that the hydrogen storage material is introduced into the supported catalyst by simple physical mixing, the interface contact between the hydrogen storage material and the catalyst is poor, the hydrogen overflow efficiency is low, and the strengthening effect is limited, a new type of catalytic system capable of realizing efficient hydrogen overflow, significantly reducing hydrogenation reaction conditions and improving reaction efficiency is developed. The core idea adopted is that: through high-energy ball milling technology, solid hydrogen storage particles and supported catalyst are treated by "nanoscale" compounding and fluidization with tetrahydrofuran (THF) or cyclohexane as a ball milling aid to build a close "hydrogen storage-catalysis" microreaction interface. The composite system not only uses the hydrogen storage material as an additional hydrogen source, but more importantly, the close interface formed in the ball milling process greatly promotes the hydrogen overflow effect, that is, the hydrogen atoms quickly migrate from the surface of the hydrogen storage material to the active sites of the catalyst, thereby creating a local high-concentration active hydrogen environment on the surface of the catalyst to promote the occurrence of hydrogen overflow.

[0028] The application will be further described below in conjunction with examples, but the protection scope of the application is not limited thereto.

[0029] Example 1 Firstly, the embodiment provides a hydrogen storage catalytic composite material and a preparation method thereof, which specifically comprises the following steps: The solid hydrogen storage material (taking MgH2 hydrogen storage alloy particles as an example) and the supported catalyst (taking a commercial nickel-tungsten catalyst as an example) are mixed in a mass ratio of 2:1 to obtain a mixture; the mixture and zirconium oxide grinding balls are put into a planetary ball mill in a ball-to-material ratio of 15:1. After sealing, hydrogen is introduced as a protective atmosphere. Tetrahydrofuran (THF) is used as a grinding aid, and the ball milling is carried out at a speed of 400 rpm for 5 hours. After the ball milling is completed, a hydrogen storage catalytic composite material (containing 0.22 g of a commercial nickel-tungsten catalyst and 0.44 g of magnesium hydride hydrogen storage material) is obtained.

[0030] The inventors found in the research process that the mixing mass ratio of the solid hydrogen storage material (MgH2) and the supported nickel-tungsten catalyst is a key parameter for regulating the performance of the composite material. When the mass ratio of the solid hydrogen storage material and the supported nickel-tungsten catalyst is 2:1, the interface between the two is most fully combined, which not only ensures the hydrogen storage capacity of MgH2 to provide a continuous hydrogen source, but also fully exposes the active sites of the catalyst to realize the efficient cooperation of "hydrogen storage and hydrogen release-catalytic hydrogenation"; if MgH2 is excessive (such as 3:1), it is easy to cover the active sites of the catalyst, which weakens the synergistic effect; if the supported nickel-tungsten catalyst is excessive (such as 1:2), the hydrogen storage is insufficient, which limits the internal hydrogen source. Therefore, the mass ratio of 2:1 of the solid hydrogen storage material and the supported nickel-tungsten catalyst is the optimal interval for balancing the hydrogen storage capacity, catalytic activity, mass transfer efficiency and stability, and is the core guarantee for realizing low-temperature and low-pressure hydrogenation.

[0031] Secondly, the embodiment provides a method for catalyzing hydrogenation of condensed ring aromatic hydrocarbon by using the hydrogen storage catalytic composite material, and the method specifically comprises the following steps: Take 0.66 g of the hydrogen storage catalytic composite material prepared in the above preparation (containing 0.22 g of commercial nickel-tungsten catalyst and 0.44 g of hydrogenated magnesium hydrogen storage material), 0.3 g of anthracene (model compound) and 20 mL of n-heptane (solvent) are added into a high-pressure reaction kettle. Hydrogen is filled at 2 Mpa, the temperature is 300 DEG C, and the reaction time is 3 hours. After the reaction is completed, the natural cooling is performed to room temperature, toluene is added to flush the inner wall of the reaction kettle and the pipeline, and the product is detected by using a gas chromatograph (GC) FID.

[0032] The inventors also found in the research process that, by selecting a suitable feeding ratio of the hydrogen storage catalytic composite material and the model compound (such as anthracene), the economic and efficient hydrogenation can be realized. If the feeding ratio of the hydrogen storage catalytic composite material is too large, the catalytic active hydrogen supply is excessive, although the conversion rate of the raw material can be accelerated, the catalyst material cost is significantly increased. On the contrary, the catalytic active hydrogen supply is insufficient, the required catalytic hydrogen supply active site is insufficient, and the conversion rate is reduced. Only when the mixing mass ratio of the hydrogen storage catalytic composite material and the raw material containing condensed ring aromatic hydrocarbon is 2.2:1, the hydrogen release rate of the hydrogen storage material and the hydrogenation consumption rate of anthracene reach a dynamic balance state, and the conversion rate is the highest.

[0033] Example 2 Different from example 1, in the method for catalyzing hydrogenation of condensed ring aromatic hydrocarbon by using the hydrogen storage catalytic composite material, the hydrogenation reaction temperature is 280 DEG C, and the preparation method is consistent with that of example 1. The specific catalytic hydrogenation method is as follows: Take 0.66 g of the hydrogen storage catalytic composite material prepared in example 1 (containing 0.22 g of commercial nickel-tungsten catalyst and 0.44 g of hydrogenated magnesium hydrogen storage material), 0.3 g of anthracene (model compound) and 20 mL of n-heptane (solvent) are added into a high-pressure reaction kettle. Hydrogen is filled at 2 Mpa, the temperature is 280 DEG C, and the reaction time is 3 hours. After the reaction is completed, the natural cooling is performed to room temperature, toluene is added to flush the inner wall of the reaction kettle and the pipeline, and the product is detected by using a gas chromatograph (GC) FID.

[0034] Example 3 Different from example 1, in the method for catalyzing hydrogenation of condensed ring aromatic hydrocarbon by using the hydrogen storage catalytic composite material, the hydrogenation reaction pressure is 1 Mpa, and the preparation method is consistent with that of example 1. The specific catalytic hydrogenation method is as follows: Take 0.66g of the above-prepared hydrogen storage catalytic composite material (containing 0.22g of commercial nickel-tungsten catalyst and 0.44g of hydrogen storage material), 0.3g of anthracene (model compound), and 20mL of n-heptane (solvent) into a high-pressure reactor. Charge 1Mpa of hydrogen, and set the temperature to 280°C. The reaction time is 3 hours. After the reaction is completed, the reactor is naturally cooled to room temperature, and toluene is added to flush the inner wall of the reactor and the pipeline. The product is detected by gas chromatography (GC) FID.

[0035] Example 4 Different from Example 1, in the method for catalyzing the hydrogenation of condensed polycyclic aromatic hydrocarbons, the hydrogen storage material in the hydrogen storage catalytic composite material is a rare earth-based hydrogen storage alloy (LaNi5), and the other preparation methods are consistent with those of Example 1. The specific catalytic hydrogenation method is as follows: Take 0.66g of the above-prepared hydrogen storage catalytic composite material (containing 0.22g of commercial nickel-tungsten catalyst and 0.44g of rare earth-based hydrogen storage alloy), 0.3g of anthracene (model compound), and 20mL of n-heptane (solvent) into a high-pressure reactor. Charge 1Mpa of hydrogen, and set the temperature to 280°C. The reaction time is 3 hours. After the reaction is completed, the reactor is naturally cooled to room temperature, and toluene is added to flush the inner wall of the reactor and the pipeline. The product is detected by gas chromatography (GC) FID.

[0036] Comparative Example 1 Different from Example 1, in the method for catalyzing the hydrogenation of condensed polycyclic aromatic hydrocarbons, the catalyst used is a commercial nickel-tungsten catalyst, and the other preparation methods are consistent with those of Example 1. The specific catalytic hydrogenation method is as follows: Take 0.22g of commercial nickel-tungsten catalyst, 0.3g of anthracene (model compound), and 20mL of n-heptane (solvent) into a high-pressure reactor. Charge 2Mpa of hydrogen, and set the temperature to 300°C. The reaction time is 3 hours. After the reaction is completed, the reactor is naturally cooled to room temperature, and toluene is added to flush the inner wall of the reactor and the pipeline. The product is detected by gas chromatography (GC) FID.

[0037] Comparative Example 2 Different from Example 1, in the method for catalyzing the hydrogenation of condensed polycyclic aromatic hydrocarbons, the catalyst used is a hydrogen storage material, and the other preparation methods are consistent with those of Example 1. The specific catalytic hydrogenation method is as follows: Take 0.44g of hydrogen storage material, 0.3g of anthracene (model compound), and 20mL of n-heptane (solvent) into a high-pressure reactor. Charge 2Mpa of hydrogen, and set the temperature to 300°C. The reaction time is 3 hours. After the reaction is completed, the reactor is naturally cooled to room temperature, and toluene is added to flush the inner wall of the reactor and the pipeline. The product is detected by gas chromatography (GC) FID.

[0038] Comparative Example 3 Different from example 1, the catalyst used in the method of catalytic hydrogenation of condensed ring aromatic hydrocarbon is a rare earth-based hydrogen storage alloy, and other preparation methods are consistent with example 1. The specific catalytic hydrogenation method is as follows: Take 0.44g of rare earth-based hydrogen storage alloy, 0.3g of anthracene (model compound) and 20mL of n-heptane (solvent) into a high-pressure reaction kettle. Fill in hydrogen 2Mpa, temperature 300℃, reaction time 3 hours. After the reaction is finished, cool it to room temperature naturally, add toluene to flush the inner wall and pipeline of the reaction kettle, and detect the product by gas chromatography (GC) FID.

[0039] The test results of different materials catalytic hydrogenation in examples and comparative examples are shown in table 1, wherein the stability test method is to separate the composite catalyst after first use, wash, centrifuge, dry and react according to the original catalytic steps.

[0040] Table 1 Hydrogenation test results of different materials

[0041] As can be seen from table 1, in example 1, the hydrogen storage catalytic composite material has 100% hydrogenation conversion rate of anthracene, which is higher than that of comparative example 1 (71.6%) using a supported catalyst alone and comparative example 2 (5.1%) using a hydrogen storage material alone. The results prove that the synergistic effect produced by the ball milling of solid hydrogen storage material and supported catalyst is not a simple physical superposition.

[0042] The conversion rate of example 2 is 98.6% under the catalytic hydrogenation reaction parameters of 280℃, 2MPa and 3h, which is at least 20℃ lower than the traditional reaction temperature (≥300℃) and still maintains high efficiency. The conversion rate of example 3 is 96.4% under the catalytic hydrogenation reaction parameters of 280℃, 1MPa and 3h, which means that the performance does not decrease obviously after the pressure is reduced by 1Mpa. It shows that the hydrogen storage catalytic composite material is strengthened by internal interface, rather than external conditions to improve reaction efficiency, which provides a certain research idea for the high energy consumption and high equipment cost of traditional hydrogenation process.

[0043] The hydrogenation conversion rate of anthracene in example 3 is still as high as 96.4% under the lower pressure of 1MPa, which proves that the dependence of the system on reaction pressure is significantly reduced.

[0044] In example 4, the hydrogen storage material in the composite material is switched, and the magnesium hydride hydrogen storage material in example 1 is replaced by a rare earth-based hydrogen storage alloy, and other conditions are the same as in example 1. The hydrogenation conversion rate of anthracene is still as high as 98.8%, which proves the universality of the system.

[0045] Comparative examples 2 and 3 prove that the hydrogen storage material itself has no catalytic activity, and the core role of example 1 is to "pump" atomic hydrogen to the active sites of the catalyst through the close interface, to build a local hydrogen-rich environment and break through the mass transfer limitation; at the same time, the hydrogen storage material acts as a dynamic "hydrogen pool" to smooth the hydrogen concentration fluctuation, avoid catalyst deactivation due to lack of hydrogen or carbon deposition, and ensure the stability of the reaction.

[0046] Figure 1 The XRD pattern of magnesium hydride in example 2 in the application is shown in Figure 2. Figure 2 It can be seen that the characteristic diffraction peak of magnesium hydride (MgH2) is sharp and has no obvious impurity peak, which confirms the characteristics of the phase of the solid hydrogen storage material used, and provides a material basis for the hydrogen storage and release performance of the composite system.

[0047] Figure 2 The XRD pattern of the material in example 1 and comparative example 1 in the application is shown in Figure 1. Figure 2 It can be seen that the diffraction pattern of the hydrogen storage catalytic composite material of example 1 retains the characteristic diffraction peaks of the commercial nickel-tungsten catalyst and MgH2 at the same time, and no new impurity phase diffraction peak appears. It shows that after mechanical ball milling, the phase structure of the two components remains complete and no harmful chemical reaction occurs, which provides a structural guarantee for the realization of synergistic effect.

[0048] Figure 3 The SEM image of the commercial nickel-tungsten catalyst in comparative example 1 in the application is shown in Figure 3. Figure 3 It can be seen that the particles of the pure commercial nickel-tungsten catalyst are in a dispersed state, and the surface is relatively smooth.

[0049] Figure 4 The SEM image of the magnesium hydride hydrogen storage material in comparative example 2 in the application is shown in Figure 4. Figure 4 It can be seen that the magnesium hydride particles are in the form of irregular blocks with large size (micron level) and dense surface, and it is difficult to form effective contact with the catalyst when used directly without effective ball milling.

[0050] Figure 5 The SEM image of the hydrogen storage catalytic composite material in example 1 in the application is shown in Figure 5, wherein the red circle encircled is the supported catalyst and the orange circle encircled is the magnesium hydride hydrogen storage particles. Figure 5 It can be seen that the hydrogen storage catalytic composite material particles are in the form of close agglomeration at the nanometer scale, the hydrogen storage material and the catalyst particles are in close contact and interface fusion, and the supported catalyst and the magnesium hydride hydrogen storage particles form a large contact area. This morphological feature directly verifies the "interface engineering" effect of the mechanical ball milling process, which provides a key structural support for the rapid overflow of hydrogen atoms, and echoes the phenomenon of synergistic effect in the reaction results.

[0051] Figure 6In the solid hydrogen storage material of the embodiment of the present application, the ball milling process is used to realize the close combination of the supported catalyst and the surface thereof, which strengthens the dispersion and interface interaction of the catalyst, in the system, the hydrogen atoms / hydrogen gas in the solid hydrogen storage material are first adsorbed on the surface of the catalyst metal particles, and then migrate from the metal surface to the carrier or the reaction region to directly participate in the hydrogenation reaction, the close interface constructed by the ball milling further optimizes the activation and migration efficiency of hydrogen, which is an important mechanism to realize the efficient coupling of the hydrogen storage and catalytic functions.

[0052] Figure 7 In the embodiment of the present application, the figure is a schematic diagram of the hydrogen storage catalytic composite material strengthening hydrogenation reaction mechanism, by comparing the mass transfer bottleneck of H2 dissolution-diffusion in the traditional hydrogenation system, the present application directly displays the hydrogen storage catalytic composite material as an "additional hydrogen source" to construct a micro-reaction interface in the hydrogenation reaction system, realize the rapid migration of hydrogen from the hydrogen storage particles to the catalyst active center after hydrogen release to reduce the mass transfer resistance, and focus on the core reaction region to make the hydrogenation raw materials and active centers directly contact to occur hydrogenation reaction, which fully reflects the technical advantages of "hydrogen storage-catalysis" synergistic hydrogenation.

[0053] The above only describes the preferred embodiments of the present application and is not used to limit the present application, for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hydrogen storage catalytic composite material, characterized in that, The hydrogen storage catalytic composite material is composed of a solid hydrogen storage material and a supported catalyst. The composite mass ratio of the solid hydrogen storage material and the supported catalyst is (1~3):1; The solid hydrogen storage material is MgH2 particles and LaNi5 particles; The supported catalyst includes a support and active components supported inside and on the surface of the support. The support includes one or more of Al2O3, SiO2, activated carbon, and molecular sieves. The active components are one or more of Ni, W, Mo, Co, Pd, and Pt.

2. The hydrogen storage catalytic composite material according to claim 1, characterized in that, The mass ratio of the solid hydrogen storage material to the supported catalyst is 2:

1. The solid hydrogen storage material is MgH2 particles; the support for the supported catalyst is either Al2O3 or SiO2, and the active components are Ni and W.

3. The hydrogen storage catalytic composite material according to claim 2, characterized in that, The supported catalyst has an active component loading of 25-35%, wherein the mass ratio of Ni to W is (1.5-2.5):1; The particle size of the hydrogen storage catalytic composite material is 110 nm-3 μm.

4. A method for preparing the hydrogen storage catalytic composite material according to any one of claims 1-3, characterized in that, Includes the following steps: A mixture is prepared by mixing solid hydrogen storage material, supported catalyst and ball milling aid; the mixture is then ball milled in an atmosphere of argon-hydrogen mixture to obtain hydrogen storage catalytic composite material. The ball-to-material ratio in the ball mill is (10~20):1, the ball mill speed is 300~500 rpm, and the ball milling time is 1~5 h.

5. The method for preparing the hydrogen storage catalytic composite material according to claim 4, characterized in that, The ball milling aid is one of tetrahydrofuran and cyclohexane; The mass ratio of the solid hydrogen storage material to the supported catalyst is (1~3):1; The solid hydrogen storage material is MgH2 particles; the supported catalyst is a nickel-tungsten catalyst. The inert atmosphere is either argon or a mixture of hydrogen and argon.

6. The application of the hydrogen storage catalytic composite material according to any one of claims 1-3 in the hydrogenation reaction of polycyclic aromatic hydrocarbons.

7. A method for hydrogenation reaction of polycyclic aromatic hydrocarbons, characterized in that, Using the hydrogen storage catalytic composite material according to any one of claims 1-3 as a catalyst, the method includes the following steps: The hydrogen storage catalytic composite material and polycyclic aromatic hydrocarbons were added to the reactor, and after the air was removed, hydrogen was introduced to carry out the hydrogenation reaction.

8. The method for hydrogenation reaction of polycyclic aromatic hydrocarbons according to claim 7, characterized in that, The polycyclic aromatic hydrocarbon is one of anthracene, phenanthrene, pyrene, benzo[a]pyrene, heavy crude oil, atmospheric residue, and vacuum residue; The mass ratio of the hydrogen storage catalytic composite material to the feedstock containing polycyclic aromatic hydrocarbons is (0.5~2.5):

1.

9. The method for hydrogenation reaction of polycyclic aromatic hydrocarbons according to claim 7, characterized in that, The initial pressure of the hydrogenation reaction is 0.1 ~ 3 MPa, the reaction temperature is 250 ~ 320 ℃, and the reaction time is 1 ~ 5 h.

10. The method for hydrogenation reaction of polycyclic aromatic hydrocarbons according to claim 7, characterized in that, The polycyclic aromatic hydrocarbon is anthracene; The mass ratio of the hydrogen storage catalytic composite material to the feedstock containing polycyclic aromatic hydrocarbons is (2~2.5):1; The initial pressure of the hydrogenation reaction is 1 to 3 MPa, the reaction temperature is 280 to 300 °C, and the reaction time is 2 to 4 hours.

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