Hydrogen storage catalytic composite material, preparation method and application thereof

Abstract

The application belongs to the technical field of advanced energy materials and green catalytic technology, and relates to a hydrogen storage catalytic composite material and a preparation method and application thereof. The hydrogen storage catalytic composite material is composed of a solid hydrogen storage material and a supported catalyst in 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 loaded on the inside and surface of the carrier, the carrier comprises one of Al2O3, SiO2, activated carbon and molecular sieve, and the active components are one or more of Ni, W, Mo, Co, Pd and Pt. The application forms a close contact interface between the two materials through ball milling, hydrogen atoms released by the hydrogen storage material at a reaction temperature rapidly overflow to the surface of the catalyst through the interface, and a local hydrogen-rich environment is created.

Description

Technical Field

[0001] This invention belongs to the interdisciplinary field of advanced energy materials and green catalysis technology, specifically relating to a hydrogen storage catalytic composite material, its preparation method, and its application. Background Technology

[0002] Catalytic hydrogenation is a chemical reaction process in which hydrogen (H2) molecules are activated and added to unsaturated organic compounds (such as alkenes and aromatics) under the action of a catalyst. This increases the hydrogen-to-carbon ratio of the feedstock and reduces its degree of unsaturation, thereby achieving the purpose of refining, modifying, or synthesizing specific chemicals. The hydrogenation of polycyclic aromatic hydrocarbons (such as anthracene) is a key step in the production of high-value-added chemicals. However, traditional catalytic hydrogenation processes typically require high temperatures (often above 300°C) and high pressures (often above 3 MPa, and sometimes even up to 20 MPa) to overcome reaction kinetic barriers and thermodynamic equilibrium limitations. This results in enormous energy consumption, high equipment investment, and potential safety risks.

[0003] The efficiency and economic benefits of catalytic hydrogenation directly depend on the performance of the catalyst. Supported catalysts are a type of heterogeneous catalyst in which active components (such as metals like Ni, Mo, and Co) are loaded onto the surface or pores of a support (such as alumina (Al₂O₃) or silica (SiO₂)) using specific methods. Due to their high specific surface area and tunable active centers, they are widely used in various hydrogenation reactions. However, their catalytic efficiency is still limited by the mass transfer efficiency of hydrogen in the reaction system, the rate of active hydrogen generation, and the hydrogen concentration on the catalyst surface. To overcome these limitations, harsh reaction conditions of high temperature and high pressure are often required to forcibly improve the mass transfer and activation efficiency of hydrogen, but this inevitably leads to problems such as high energy consumption, large equipment investment, and increased safety risks. Summary of the Invention

[0004] The purpose of this invention is to provide a hydrogen storage catalytic composite material, its preparation method, and its application, thereby overcoming the shortcomings of the prior art. By mechanically ball milling in an inert / hydrogen-argon mixed atmosphere, a solid hydrogen storage material and catalyst (supported type) composite material are constructed. When applied to the hydrogenation conversion of polycyclic aromatic hydrocarbons, it achieves efficient hydrogen overflow, significantly reduces hydrogenation reaction conditions, and improves reaction efficiency.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention 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 materials are MgH2 particles and LaNi5 particles; Supported catalysts include 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, and the active components are one or more of Ni, W, Mo, Co, Pd and Pt.

[0006] Solid hydrogen storage materials are functional materials capable of reversibly absorbing and releasing hydrogen under specific conditions, such as magnesium-based hydrogen storage materials (e.g., MgH2) and rare-earth-based hydrogen storage alloys (e.g., AB5-type LaNi5). They can reversibly absorb and release hydrogen under mild conditions. Traditionally, research and applications of these materials have mainly focused on hydrogen storage and transportation. By ball milling and mixing supported catalysts with solid hydrogen storage materials, the controllable release of hydrogen by the solid hydrogen storage materials under reaction conditions is utilized to provide a high concentration of active hydrogen in situ near the active sites of the catalyst, eliminating dependence on high-pressure external hydrogen sources and achieving efficient hydrogenation under milder conditions. This invention forms a large, tight contact interface between the two materials through ball milling. Hydrogen atoms released by the hydrogen storage material at the reaction temperature can rapidly "overflow" to the catalyst surface through the interface, providing a continuous supply of active hydrogen species for the hydrogenation reaction. This avoids the mass transfer limitations of hydrogen dissolution and diffusion in traditional systems, creating a localized hydrogen-rich environment.

[0007] In some other embodiments, the composite 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.

[0008] Solid hydrogen storage materials, especially magnesium-based hydrogen storage materials (such as MgH2), can reversibly absorb and release hydrogen under mild conditions, introducing it into catalytic reactions. By utilizing their "hydrogen pump" characteristics, they can provide active hydrogen to the reaction in situ, thereby reducing the severity of reaction conditions.

[0009] In some other embodiments, the loading of the active component in the supported catalyst is 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.

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

[0011] In a second aspect, the present invention provides a method for preparing the hydrogen storage catalytic composite material described in the first aspect, comprising the following steps: A mixture is prepared by mixing solid hydrogen storage material, supported catalyst and ball milling aid; the mixture is ball milled in an atmosphere of argon-hydrogen mixture (5% hydrogen, 95% argon) 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.

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

[0013] This invention utilizes high-energy ball milling technology to composite and fluidize solid hydrogen storage particles with supported catalysts at the nanoscale, using tetrahydrofuran (THF) or cyclohexane as milling aids, thus constructing a tight hydrogen storage-catalysis micro-reaction interface. This composite system not only utilizes the hydrogen storage material as an additional hydrogen source, but more importantly, the tight interface formed during ball milling greatly promotes the hydrogen spillover effect—that is, hydrogen atoms rapidly migrate from the surface of the hydrogen storage material to the active sites of the catalyst, thereby creating a locally high-concentration active hydrogen environment on the catalyst surface, 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; the supported catalyst is a nickel-tungsten catalyst. The inert atmosphere is a mixture of hydrogen and argon to isolate it from air and prevent the active powder generated by high-energy collisions during ball milling from being oxidized.

[0015] Thirdly, the present invention provides the application of the hydrogen storage catalytic composite material described in the first aspect in the hydrogenation reaction of polycyclic aromatic hydrocarbons.

[0016] Fourthly, the present invention provides a method for hydrogenation of polycyclic aromatic hydrocarbons, using the hydrogen storage catalytic composite material described in the first aspect as a catalyst, comprising 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.

[0017] Hydrogen storage materials act as a dynamic "hydrogen pool" in the reaction system, which can smooth out fluctuations in hydrogen concentration during the reaction process, stabilize the hydrogenation performance of the catalyst, and prevent the catalyst from becoming deactivated or carbonized due to local hydrogen deficiency.

[0018] In some other embodiments, 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.

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

[0020] In some other embodiments, 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 ~ 3 MPa, the reaction temperature is 280 ~ 300 ℃, and the reaction time is 2 ~ 4 h.

[0021] The beneficial effects of this invention are: (1) This invention establishes a tight interfacial contact between the hydrogen storage material and the catalyst through hydrogenation and ball milling processes. This allows the hydrogen storage material to act as an "in-situ hydrogen pump," continuously releasing active hydrogen atoms during the reaction and rapidly overflowing to the active sites of the catalyst through the interface, creating a localized high-concentration active hydrogen environment. This effectively overcomes the mass transfer limitations of hydrogen dissolution and diffusion in traditional processes, becoming key to improving reaction kinetics. Simultaneously, the hydrogen storage material can act as a dynamic "hydrogen pool," smoothing hydrogen concentration fluctuations during the reaction process and providing stable hydrogen supply to the active sites of the catalyst. This effectively prevents problems such as catalyst deactivation and coking caused by localized instantaneous hydrogen deficiency, improving the operational stability and lifespan of the system.

[0022] (2) The ball milling process adopted in this invention is relatively mature, widely applicable, green, and easy to scale up, with good industrialization prospects. It is expected to be widely used in fields requiring efficient hydrogenation, such as heavy oil processing and deep coal tar processing, providing a brand-new solution for developing a new generation of mild, efficient, and safe catalytic hydrogenation technology.

[0023] (3) The hydrogen storage catalytic composite material prepared in this invention achieves a hydrogenation conversion rate of up to 93.9% for typical polycyclic aromatic hydrocarbons (anthracene) under optimized conditions of 300 °C and 2 MPa, which is far higher than the conversion rate of a single catalyst system under the same conditions (25.6%). This proves that the composite is not a simple superposition of functions, but rather significantly improves the intrinsic catalytic efficiency through interfacial synergy. It can achieve high-efficiency conversion under milder conditions. Under conditions of 280 °C (reduced by 20 °C) and 1 MPa (pressure reduced by 50%), the conversion rate of anthracene can still be maintained at extremely high levels of 98.7% and 98.4%, respectively. This characteristic of "enhancing efficiency with cooling and high efficiency with pressure reduction" subverts the traditional catalytic model that relies on increasing reaction intensity to strengthen the process, fundamentally reducing energy consumption, equipment requirements, and safety risks. Attached Figure Description

[0024] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0025] Figure 1 The X-ray powder diffraction pattern of magnesium hydride solid hydrogen storage powder, the test material in Comparative Example 2 of this invention; Figure 2 The X-ray powder diffraction patterns of the materials tested in Example 1 and Comparative Example 1 of this invention are shown below. Figure 3 This is a scanning electron microscope image of the commercial nickel-tungsten catalyst tested in Comparative Example 1 of this invention; Figure 4 This is a scanning electron microscope image of magnesium hydride solid hydrogen storage powder, the test material in Comparative Example 2 of this invention. Figure 5 This is a scanning electron microscope image of the compact composite of solid hydrogen storage material and supported catalyst in Example 1 of the present invention; Figure 6 This is a schematic diagram of the hydrogen overflow effect in Embodiment 1 of the present invention; Figure 7 This is a schematic diagram of the synergistic reinforcement mechanism of the hydrogenation reaction micro-interface in the composite material system of Example 1 of the present invention. Detailed Implementation

[0026] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of the invention. Specific conditions are not specified in the embodiments; they were performed under conventional conditions or conditions recommended by the manufacturer. Components not specifying a manufacturer are all commercially available conventional products. The type of supported catalyst is not specifically limited; generally, any common supported catalyst is acceptable. In the embodiments, a commercially available nickel-tungsten catalyst, selectable from Shandong Gaodulutian Catalyst Co., Ltd., was used.

[0027] To address the problems of poor interfacial contact between hydrogen storage materials and catalysts, low hydrogen spillover efficiency, and limited enhancement effects in current methods of introducing hydrogen storage materials into supported catalysts through simple physical mixing, this invention develops a novel catalytic system that achieves efficient hydrogen spillover, significantly reduces hydrogenation reaction conditions, and improves reaction efficiency. The core concept involves using high-energy ball milling technology to composite and fluidize solid hydrogen storage particles with a supported catalyst at the nanoscale, using tetrahydrofuran (THF) or cyclohexane as milling aids to construct a tight hydrogen storage-catalysis micro-reaction interface. This composite system not only utilizes the hydrogen storage material as an additional hydrogen source, but more importantly, the tight interface formed during ball milling greatly promotes the hydrogen spillover effect—that is, hydrogen atoms rapidly migrate from the surface of the hydrogen storage material to the active center of the catalyst, thereby creating a locally high-concentration active hydrogen environment on the catalyst surface and promoting hydrogen spillover.

[0028] The present invention will be further described below with reference to embodiments, but the scope of protection of the present invention is not limited thereto.

[0029] Example 1 First, this embodiment provides a hydrogen storage catalytic composite material and its preparation method, specifically including the following steps: Solid hydrogen storage material (using MgH2 hydrogen storage alloy particles as an example) was mixed with a supported catalyst (using a commercial nickel-tungsten catalyst as an example) at a mass ratio of 2:1 to obtain a mixture. The mixture and zirconia grinding balls were then placed together in a planetary ball mill at a ball-to-material ratio of 15:1. After sealing, hydrogen gas was introduced as a protective atmosphere. Tetrahydrofuran (THF) was used as a grinding aid, and the mixture was ball-milled at 400 rpm for 5 hours. After ball milling, a hydrogen storage catalytic composite material (containing 0.22 g of commercial nickel-tungsten catalyst and 0.44 g of magnesium hydride hydrogen storage material) was obtained.

[0030] During their research, the inventors discovered that the mixing mass ratio of solid hydrogen storage material (MgH2) to supported nickel-tungsten catalyst is a key parameter for regulating the performance of the composite material. When the mass ratio of solid hydrogen storage material to supported nickel-tungsten catalyst is 2:1, the interfacial bonding between the two is most complete. This ensures both the hydrogen storage capacity of MgH2 to provide a continuous hydrogen source and the full exposure of the catalyst's active sites, achieving a highly efficient synergistic effect of "hydrogen storage and release - catalytic hydrogenation." If MgH2 is excessive (e.g., 3:1), it easily covers the catalyst's active sites, weakening the synergistic effect. If the supported nickel-tungsten catalyst is excessive (e.g., 1:2), insufficient hydrogen storage leads to a limited internal hydrogen source. Therefore, a mass ratio of 2:1 for solid hydrogen storage material to supported nickel-tungsten catalyst is the optimal range for balancing hydrogen storage capacity, catalytic activity, mass transfer efficiency, and stability, and is the core guarantee for achieving efficient hydrogenation at low temperature and low pressure.

[0031] Secondly, this embodiment provides a method for hydrogenating polycyclic aromatic hydrocarbons using a hydrogen storage catalytic composite material, specifically including the following steps: Take 0.66 g of the hydrogen storage catalytic composite material prepared above (containing 0.22 g of commercial nickel-tungsten catalyst and 0.44 g of magnesium hydride hydrogen storage material), add it to a high-pressure reactor along with 0.3 g of anthracene (model compound) and 20 mL of n-heptane (solvent). Purge with hydrogen at 2 MPa, maintain the temperature at 300 °C, and react for 3 hours. After the reaction is complete, allow it to cool naturally to room temperature. Add toluene to rinse the inner wall and pipelines of the reactor, and analyze the products using gas chromatography (GC) with FID.

[0032] The inventors also discovered during their research that selecting an appropriate feed ratio between the hydrogen storage catalytic composite material and the model compound (such as anthracene) can achieve economical and efficient hydrogenation. If the feed ratio of the hydrogen storage catalytic composite material is too high, there will be an excess of catalytically active hydrogen, which, while accelerating the feed conversion rate, will significantly increase the cost of the catalyst material. Conversely, insufficient catalytically active hydrogen will result in a lack of the required catalytic hydrogen-donating active sites, leading to a decrease in conversion rate. Only when the mass ratio of the hydrogen storage catalytic composite material to the feed containing polycyclic aromatic hydrocarbons is 2.2:1 does the hydrogen release rate of the hydrogen storage material and the hydrogenation consumption rate of anthracene reach a dynamic equilibrium, resulting in the highest conversion rate.

[0033] Example 2 Unlike Example 1, in the method for hydrogenating polycyclic aromatic hydrocarbons using a hydrogen storage catalytic composite material, the hydrogenation reaction temperature is 280°C, while other preparation methods are the same as in Example 1. The specific catalytic hydrogenation method is as follows: 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 magnesium hydride hydrogen storage material) was added to a high-pressure reactor along with 0.3 g of anthracene (model compound) and 20 mL of n-heptane (solvent). Hydrogen gas was introduced at 2 MPa, the temperature was set at 280 °C, and the reaction time was 3 hours. After the reaction was complete, the reactor was allowed to cool naturally to room temperature. Toluene was added to rinse the inner wall and pipelines of the reactor, and the products were detected by gas chromatography (GC) with FID.

[0034] Example 3 Unlike Example 1, in the method for catalytic hydrogenation of polycyclic aromatic hydrocarbons using a hydrogen storage catalytic composite material, the pressure of the hydrogenation reaction is 1 MPa, while other preparation methods are the same as in Example 1. The specific catalytic hydrogenation method is as follows: Take 0.66 g of the hydrogen storage catalytic composite material prepared above (containing 0.22 g of commercial nickel-tungsten catalyst and 0.44 g of magnesium hydride hydrogen storage material), add it to a high-pressure reactor along with 0.3 g of anthracene (model compound) and 20 mL of n-heptane (solvent). Purge with hydrogen gas at 1 MPa, maintain the temperature at 280 °C, and react for 3 hours. After the reaction is complete, allow it to cool naturally to room temperature. Add toluene to rinse the inner wall and pipelines of the reactor, and analyze the products using gas chromatography (GC) with FID.

[0035] Example 4 Unlike Example 1, in the method for catalytic hydrogenation of polycyclic aromatic hydrocarbons using a hydrogen storage catalytic composite material, the hydrogen storage material in the composite material is a rare earth-based hydrogen storage alloy (LaNi5), while the other preparation methods are the same as in Example 1. The specific catalytic hydrogenation method is as follows: Take 0.66 g of the hydrogen storage catalytic composite material prepared above (containing 0.22 g of commercial nickel-tungsten catalyst and 0.44 g of rare earth-based hydrogen storage alloy), add it to a high-pressure reactor along with 0.3 g of anthracene (model compound) and 20 mL of n-heptane (solvent). Purge with hydrogen gas at 1 MPa, maintain the temperature at 280 °C, and react for 3 hours. After the reaction is complete, allow it to cool naturally to room temperature. Add toluene to rinse the inner wall and pipelines of the reactor, and analyze the products using gas chromatography (GC) with FID.

[0036] Comparative Example 1 Unlike Example 1, the catalyst used in the catalytic hydrogenation method for polycyclic aromatic hydrocarbons is a commercially available nickel-tungsten catalyst; the other preparation methods are the same as in Example 1. The specific catalytic hydrogenation method is as follows: 0.22 g of commercial nickel-tungsten catalyst, 0.3 g of anthracene (model compound), and 20 mL of n-heptane (solvent) were added to a high-pressure reactor. Hydrogen gas was introduced at 2 MPa, the temperature was set at 300 °C, and the reaction time was 3 hours. After the reaction was complete, the reactor was allowed to cool naturally to room temperature. Toluene was added to rinse the inner wall and pipelines of the reactor. The products were detected by gas chromatography (GC) with FID.

[0037] Comparative Example 2 Unlike Example 1, the catalyst used in the catalytic hydrogenation method for polycyclic aromatic hydrocarbons is magnesium hydride hydrogen storage material; other preparation methods are the same as in Example 1. The specific catalytic hydrogenation method is as follows: 0.44 g of magnesium hydride hydrogen storage material, 0.3 g of anthracene (model compound), and 20 mL of n-heptane (solvent) were added to a high-pressure reactor. Hydrogen gas was introduced at 2 MPa, the temperature was set at 300 °C, and the reaction time was 3 hours. After the reaction was complete, the reactor was allowed to cool naturally to room temperature. Toluene was added to rinse the inner wall and pipelines of the reactor. The products were detected by gas chromatography (GC) with FID.

[0038] Comparative Example 3 Unlike Example 1, the catalyst used in the catalytic hydrogenation method for polycyclic aromatic hydrocarbons is a rare earth-based hydrogen storage alloy; other preparation methods are the same as in Example 1. The specific catalytic hydrogenation method is as follows: 0.44 g of rare earth-based hydrogen storage alloy, 0.3 g of anthracene (model compound), and 20 mL of n-heptane (solvent) were added to a high-pressure reactor. Hydrogen gas was introduced at 2 MPa, the temperature was set at 300 °C, and the reaction time was 3 hours. After the reaction was complete, the reactor was allowed to cool naturally to room temperature. Toluene was added to rinse the inner wall and pipelines of the reactor. The products were then analyzed by gas chromatography (GC) with FID.

[0039] The test results of hydrogenation using different materials in the examples and comparative examples are shown in Table 1. The stability test method is to separate the composite catalyst after the first use, wash, centrifuge, dry it, and then carry out the reaction according to the original catalytic steps.

[0040] Table 1. Hydrogenation test results for different materials

[0041] As shown in Table 1, in Example 1, the hydrogen conversion rate of the hydrogen storage catalyst composite material for anthracene was 100%, exceeding that of Comparative Example 1 (71.6%) using a supported catalyst alone and Comparative Example 2 (5.1%) using a hydrogen storage material alone. This result confirms that the synergistic effect produced by the ball milling composite of the solid hydrogen storage material and the supported catalyst is not a simple physical additive effect.

[0042] Example 2 showed a conversion rate of 98.6% under catalytic hydrogenation reaction parameters of 280 °C, 2 MPa, and 3 h, maintaining high efficiency even at a temperature at least 20 °C lower than the conventional reaction temperature (≥300 °C). Example 3 achieved a conversion rate of 96.4% under catalytic hydrogenation reaction parameters of 280 °C, 1 MPa, and 3 h, indicating no significant performance degradation after a 1 MPa pressure reduction. This demonstrates that the hydrogen storage catalytic composite material improves reaction efficiency through internal interface reinforcement rather than external conditions, providing a research approach to address the high energy consumption and high equipment costs of traditional hydrogenation processes.

[0043] In Example 3, the hydrogenation conversion rate of anthracene was still as high as 96.4% at a relatively low pressure of 1 MPa, demonstrating that the system's dependence on reaction pressure was significantly reduced.

[0044] In Example 4, the hydrogen storage material in the composite material was changed, and the magnesium hydride hydrogen storage material in Example 1 was replaced with a rare earth-based hydrogen storage alloy. Other conditions were the same as in Example 1. The hydrogenation conversion rate of anthracene was still as high as 98.8%, which proved the universality of the system.

[0045] Comparative Examples 2 and 3 demonstrate that the hydrogen storage material itself has no catalytic activity. The core function of Example 1 is to "pump" atomic hydrogen to the active sites of the catalyst through a tight interface, thereby creating a local hydrogen-rich environment and overcoming mass transfer limitations. At the same time, the hydrogen storage material acts as a dynamic "hydrogen pool," smoothing out hydrogen concentration fluctuations, preventing catalyst deactivation or carbon buildup due to hydrogen deficiency, and ensuring reaction stability.

[0046] Figure 1 This is the XRD pattern of magnesium hydride in Example 2 of this invention. Figure 2 It can be seen that the characteristic diffraction peaks of magnesium hydride (MgH2) are sharp and without obvious impurities, which confirms the proper characteristics of the solid hydrogen storage material phase and provides a material basis for the hydrogen storage and release performance of the composite system.

[0047] Figure 2 These are the XRD patterns of the materials used in Example 1 and Comparative Example 1 of this invention. Figure 2 As can be seen, the diffraction patterns of the hydrogen storage catalytic composite material in Example 1 retain the characteristic diffraction peaks of both the commercial nickel-tungsten catalyst and MgH2, without the appearance of new impurity phase diffraction peaks. This indicates that after mechanical ball milling and composite, the phase structures of the two components remain intact, and no harmful chemical reactions occur, providing structural assurance for the realization of synergistic effects.

[0048] Figure 3 This is a SEM image of the commercial nickel-tungsten catalyst used in Comparative Example 1 of this invention. Figure 3 It can be seen that the pure commercial nickel-tungsten catalyst particles are in a dispersed state and have a relatively smooth surface.

[0049] Figure 4 This is a SEM image of the magnesium hydride hydrogen storage material in Comparative Example 2 of this invention. Figure 4 It is known that magnesium hydride particles are irregularly shaped lumps with large sizes (micrometers) and dense surfaces. Without effective ball milling, they are difficult to form effective contact with the catalyst when used directly.

[0050] Figure 5 This is a SEM image of the hydrogen storage catalytic composite material in Example 1 of the present invention. The supported catalyst is circled in red, and the magnesium hydride hydrogen storage particles are marked in orange. Figure 5 It is evident that the hydrogen storage catalyst composite material particles exhibit a tightly aggregated morphology at the nanoscale, with close contact and interfacial fusion between the hydrogen storage material and catalyst particles, forming a large contact area between the supported catalyst and the magnesium hydride hydrogen storage particles. This morphological feature directly confirms the "interface engineering" effect of the mechanical ball milling process, providing crucial structural support for the rapid overflow of hydrogen atoms, echoing the synergistic effect observed in the reaction results.

[0051] Figure 6In this embodiment of the invention, the solid hydrogen storage material is ball-milled to achieve a tight bond between the supported catalyst and its surface. This bond enhances the dispersion of the catalyst and the interfacial interaction. In this system, 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 support or reaction region to directly participate in the hydrogenation reaction. The tight interface constructed by ball milling further optimizes the activation and migration efficiency of hydrogen, which is an important mechanism for achieving efficient coupling of hydrogen storage and catalytic functions.

[0052] Figure 7 This figure, as an embodiment of the present invention, is a schematic diagram of the hydrogen storage catalytic composite material enhancing the hydrogenation reaction mechanism. By comparing the mass transfer bottleneck of H2 dissolution-diffusion in the traditional hydrogenation system, it intuitively demonstrates that the hydrogen storage catalytic composite material of the present invention, as an "extra hydrogen source," constructs a micro-reaction interface in the hydrogenation reaction system. This enables hydrogen to rapidly migrate to the active center of the catalyst after the hydrogen storage particles release hydrogen, thereby reducing mass transfer resistance. At the same time, it focuses on the core reaction region, allowing the hydrogenation feedstock to directly contact the active center and undergo a hydrogenation reaction, fully demonstrating the technical advantages of "hydrogen storage-catalysis" synergistic enhancement of hydrogenation.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The application of a hydrogen storage catalytic composite material in the hydrogenation reaction of polycyclic aromatic hydrocarbons, characterized in that, The application includes the following steps: adding the hydrogen storage catalytic composite material and polycyclic aromatic hydrocarbons into a reaction vessel, removing the air, and then filling with hydrogen to carry out a hydrogenation reaction; The hydrogen storage catalytic composite material is composed of a solid hydrogen storage material and a supported catalyst. The supported catalyst includes a support and active components supported inside and on the surface of the support; 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 one of Al2O3 and SiO2, and the active components are Ni and W. The preparation method of hydrogen storage catalytic composite material 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.

2. The application according to claim 1, 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.

3. The application according to claim 1, characterized in that, The ball milling aid is one of tetrahydrofuran and cyclohexane.

4. The application according to claim 1, 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.

5. The application according to claim 1, 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.

6. The application according to claim 1, 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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