Hydrogen storage material, hydrogen storage composition and use, hydrogen storage and desorption method

Abstract

The application provides a hydrogen storage material and a hydrogen storage and desorption method. The hydrogen storage material provided by the application comprises a compound shown in formula I: wherein R comprises hydrogen or methyl, the hydrogen storage capacity of the hydrogen storage material can reach 7.2 wt%, the hydrogen storage capacity meets the demand of the hydrogen energy storage field for the hydrogen storage material, meanwhile, the thermal stability of the hydrogen storage material is good, the hydrogen storage material is in a liquid state in the range of-40 to 250 DEG C, the hydrogen storage material can keep a liquid state in the hydrogenation and dehydrogenation process, so that the hydrogenation and dehydrogenation reaction efficiency can be maintained, and the hydrogen storage material has practicability and a good application prospect. The hydrogen storage and desorption method provided by the application can realize hydrogen storage and desorption at a lower temperature, and solves the problems of material decomposition, high energy consumption and catalyst deactivation caused by excessively high hydrogenation and dehydrogenation temperature.

Description

Technical Field

[0001] This invention belongs to the field of liquid organic hydrogen storage technology, and designs a hydrogen storage material, a hydrogen storage composition and its application, and a method for hydrogen storage and desorption; specifically, it relates to a hydrogen storage material and its application, a hydrogen storage composition and its application, and a method for hydrogen storage and desorption. Background Technology

[0002] Hydrogen has a high calorific value and its combustion product is water, making it one of the cleanest energy sources in the world. Therefore, developing hydrogen energy is an important choice for achieving dual-carbon goals. Hydrogen storage is the bridge connecting hydrogen production and consumption, and it is one of the bottleneck technologies for achieving large-scale hydrogen energy utilization. Currently, the main hydrogen storage methods include: high-pressure gaseous hydrogen storage, cryogenic liquid hydrogen storage, solid-state hydrogen storage, and liquid organic hydrogen storage. Different hydrogen storage methods have their own advantages and disadvantages, and can complement each other to adapt to different application scenarios. Among them, liquid organic hydrogen storage has the advantage of good hydrogen storage stability and is the only hydrogen storage technology that operates at room temperature and pressure. It can also be transported using existing oil and gas transportation systems, giving it a unique advantage in long-distance transportation.

[0003] Liquid organic hydrogen storage technology generally uses organic materials as hydrogen storage materials, utilizing metal catalysts to achieve hydrogen storage and release. Currently developed organic hydrogen storage systems include those based on cyclic alkanes and aromatics, such as the benzene / cyclohexane system (7.1 wt% hydrogen storage capacity), the toluene / methylcyclohexane system (6.1 wt% hydrogen storage capacity), or dibenzyltoluene and its corresponding cyclohexane system (6.2 wt% hydrogen storage capacity). Hydrogen storage systems based on nitrogen heterocycles include N-ethylcarbazole / dodecylhydro-N-ethylcarbazole (5.8 wt% hydrogen storage capacity) and 2,6-dimethylpyridine / 2,6-dimethylpiperidine (5.3 wt% hydrogen storage capacity). Catalysts are mainly ruthenium, palladium, and platinum.

[0004] However, hydrogen storage systems based on cyclic alkanes generally require temperatures above 230°C for dehydrogenation, which is often higher than the boiling point of the storage material. Nitrogen heterocyclic hydrogen storage materials typically require temperatures above 170°C. These high dehydrogenation temperatures not only consume a lot of energy but also place high demands on the pressure resistance and cooling of the equipment, and can lead to adverse effects such as material decomposition and catalyst deactivation. Furthermore, the U.S. Department of Energy has calculated that hydrogen storage materials meeting future development requirements need a mass hydrogen storage capacity of 6.5 wt%, but most current hydrogen storage systems based on liquid organic materials have low mass hydrogen storage capacities and poor practicality. Therefore, developing organic hydrogen storage methods with high hydrogen storage capacity and mild dehydrogenation conditions is one of the urgent problems to be solved in the field of liquid organic hydrogen storage technology. Summary of the Invention

[0005] To address all or part of the above-mentioned problems, one objective of this invention is to provide a hydrogen storage material comprising the compound shown in Formula I:

[0006]

[0007] R includes hydrogen or methyl.

[0008] In some embodiments, the hydrogen storage capacity of the hydrogen storage material is 6.53 wt% to 7.2 wt%.

[0009] A second objective of this invention is to provide a hydrogen storage composition comprising the hydrogen storage material and hydrogen storage catalyst described in the above-mentioned technical solutions.

[0010] In some preferred embodiments, the hydrogen storage catalyst includes one or more of Ru, Pt, Pd, and Co-NPs.

[0011] In some preferred embodiments, the hydrogen storage catalyst is supported on a first support, which includes one or more of Al2O3, AC, TiO2, SiO2, CeO2 and ZnO.

[0012] In some preferred embodiments, the molar ratio of the hydrogen storage catalyst to the hydrogen storage material is 1:5000 to 1:20.

[0013] The third objective of this invention is to provide the application of the hydrogen storage materials or hydrogen storage catalysts described in the above-mentioned technical solutions in hydrogen storage.

[0014] The fourth objective of this invention is to provide a hydrogen storage method, comprising: in the presence of a hydrogen storage catalyst, contacting the hydrogen storage material described in the above technical solution with a hydrogen-containing gas and performing a hydrogenation reaction.

[0015] In some preferred embodiments, the reaction temperature of the hydrogenation reaction is 80–180°C.

[0016] In some preferred embodiments, the hydrogenation reaction takes 0.5 to 24 hours.

[0017] In some preferred embodiments, the hydrogen storage catalyst includes one or more of Ru, Pt, Pd, and Co-NPs.

[0018] In some preferred embodiments, the hydrogen storage catalyst is supported on a first support, which includes one or more of Al2O3, AC, TiO2, SiO2, CeO2, and ZnO.

[0019] In some preferred embodiments, the molar ratio of the hydrogen storage catalyst to the hydrogen storage material is 1:5000 to 1:20.

[0020] In some preferred embodiments, the products of the hydrogenation reaction include one or more compounds represented by Formula II, Formula III, and Formula IV.

[0021]

[0022] In some embodiments, the hydrogen storage method specifically includes: placing at least the hydrogen storage material and the hydrogen storage catalyst in a reaction vessel; replacing the gas in the reaction vessel with hydrogen-containing gas; and introducing hydrogen-containing gas at a set pressure into the reaction vessel to carry out the hydrogenation reaction.

[0023] In some embodiments, introducing hydrogen-containing gas at a set pressure into the reaction vessel can specifically mean: introducing hydrogen-containing gas at a set pressure into the reaction vessel multiple times at set time intervals.

[0024] In some preferred embodiments, the reaction vessel is a high-pressure reactor.

[0025] In some preferred embodiments, the set pressure is 0.1 to 8 MPa.

[0026] In some preferred embodiments, the hydrogen-containing gas is hydrogen.

[0027] In some embodiments, the hydrogen storage method specifically includes: placing a mixed reaction system containing the hydrogen storage material, the hydrogen storage catalyst, and the first solvent in the reaction vessel to carry out the hydrogenation reaction.

[0028] Of course, the hydrogen storage method may also be without the need to add a first solvent. In some embodiments, the hydrogen storage material shown in Formula I can itself be used as a solvent. After being mixed with the hydrogen storage catalyst, it is placed in the reaction vessel to carry out the hydrogenation reaction.

[0029] In some preferred embodiments, the first solvent includes one or more of n-hexane, cyclohexane, n-heptane, tetrahydrofuran, and dioxane.

[0030] In some preferred embodiments, the volume ratio of the first solvent to the hydrogen storage material is 10:1 to 0.0001:1, wherein the amount of hydrogen storage material used is greater than zero.

[0031] The fifth objective of this invention is to provide a hydrogen desorption method, comprising: subjecting a material storing hydrogen to a dehydrogenation reaction in the presence of a dehydrogenation catalyst to obtain a hydrogen storage material and hydrogen.

[0032] The material storing hydrogen includes compounds of formula IV:

[0033]

[0034] The hydrogen storage material includes the compound shown in Formula I:

[0035]

[0036] Wherein, R includes hydrogen or methyl.

[0037] In some embodiments, the dehydrogenation reaction temperature is 110–230°C.

[0038] In some embodiments, the dehydrogenation reaction time is 1 to 180 hours.

[0039] In some embodiments, the dehydrogenation catalyst includes, but is not limited to, one or more of Pd(OAc)2, Ir, Pt, and Pd.

[0040] In some embodiments, the dehydrogenation catalyst is supported on a second support, which includes one or more of γ-Al2O3, ZnO, SiO2, CeO2, TiO2, and AC.

[0041] In some preferred embodiments, the dehydrogenation catalyst and the second support comprise one or more of Pd(OAc)2-γ-Al2O3, Pd(OAc)2-CeO2, Pd(OAc)2-TiO2, and Pd(OAc)2-AC. In some preferred embodiments, the dehydrogenation catalyst and the second support comprise Pt / AC and Pd / AC.

[0042] In some embodiments, the molar ratio of the dehydrogenation catalyst to the hydrogen-containing material is 1:5000 to 1:20.

[0043] In some embodiments, the hydrogen desorption method specifically includes: carrying out a dehydrogenation reaction in a mixed reaction system containing the hydrogen-containing material, a dehydrogenation catalyst, and a second solvent under a protective atmosphere.

[0044] Of course, the hydrogen desorption method may also be performed without adding a second solvent. In some embodiments, the material containing hydrogen as shown in Formula IV can itself be used as a solvent to mix with the dehydrogenation catalyst to carry out the dehydrogenation reaction.

[0045] In some embodiments, the second solvent includes one or more of toluene, xylene, trimethylbenzene, dioxane, nonane, and dodecane.

[0046] In some preferred embodiments, the second solvent includes one or more of nonane, dodecane, and trimethylbenzene. More preferably, the second solvent includes trimethylbenzene.

[0047] In some embodiments, the volume ratio of the second solvent to the hydrogen-containing material is 10:1 to 0.0001:1, wherein the amount of hydrogen-containing material is greater than zero.

[0048] In some embodiments, the protective atmosphere includes nitrogen and / or an inert gas.

[0049] The sixth objective of this invention is to provide a method for hydrogen storage and desorption, comprising: obtaining a material storing hydrogen using the hydrogen storage method described in any one of the above technical solutions; and releasing hydrogen from the hydrogen-stored material using the hydrogen desorption method described in any one of the above technical solutions, wherein the hydrogen yield during the hydrogen desorption process is 1-100%.

[0050] Compared with the prior art, the present invention has at least the following beneficial effects:

[0051] (1) The hydrogen storage material provided by the present invention has a hydrogen storage capacity of up to 7.2 wt%, which is higher than the hydrogen storage system of cyclic alkanes that have been disclosed so far. It meets the hydrogen storage capacity requirements of hydrogen storage materials in the field of hydrogen energy storage and has practicality and good application prospects.

[0052] (2) The hydrogen storage material provided by the present invention has good thermal stability and is in liquid state in the range of -40 to 250°C. It can remain liquid during hydrogenation and dehydrogenation to maintain good hydrogenation and dehydrogenation reaction efficiency.

[0053] (3) The present invention provides a hydrogen storage method that can be realized in the range of 80 to 180°C, and a hydrogen desorption method that can be realized in the range of 110 to 230°C. The reaction temperature of the hydrogenation process and the dehydrogenation process is mild, which is not likely to cause material decomposition or catalyst deactivation.

[0054] (4) The hydrogen storage and desorption method provided by the present invention has a simple reaction process, low energy consumption, low equipment requirements, and has the prospect of large-scale development. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is a gas chromatogram of the product in Example 1 of this application;

[0057] Figure 2 This is a gas chromatogram of the product in Example 39 of this application. Detailed Implementation

[0058] The technical solutions of the present invention will be described in detail below with reference to specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention. The specific functional details disclosed herein should not be construed as limiting, but are merely intended to form the basis of the claims and to teach those skilled in the art to employ the representative basis of the invention in different ways in any suitable detailed embodiment.

[0059] Unless otherwise specified, all experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0060] Example 1

[0061] This embodiment provides a hydrogen storage method, the reaction process of which is as follows:

[0062]

[0063] Add the hydrogen storage catalyst Ru (100 mg, 0.5 mol%; Ru supported on Al2O3), 2-methylquinoline (1.43 g, 10 mmol), and n-hexane (10 mL) to a 50 mL high-pressure reactor, and cover the reactor.

[0064] The gas inside the high-pressure reactor was replaced six times with hydrogen gas at 1.0 MPa.

[0065] Hydrogen gas was pressurized to 5.0 MPa and subjected to a hydrogenation reaction at 150 °C. After 5 hours of reaction, the hydrogen pressure no longer decreased. The mixture was then cooled to room temperature, the gas was released, and Ru / Al2O3 and the reaction liquid were separated by filtration. The catalyst Ru / Al2O3 could be recycled.

[0066] Figure 1 This is the gas chromatogram of the reaction solution in this embodiment. Figure 1 As can be seen, 2-methylquinoline (the compound shown in Formula Ia) is completely converted to 2-methyldecahydroquinoline (the compound shown in Formula IV-a). The reaction solution is concentrated under vacuum to obtain pure 2-methyldecahydroquinoline with a yield of 100% and a hydrogen storage capacity of 6.53 wt%. It should be noted that because the compound shown in Formula IV has three chiral centers and four diastereomers, therefore... Figure 1 The gas chromatogram shown has 4 peaks.

[0067] Example 2

[0068] This embodiment provides a hydrogen storage method, the reaction process of which is as follows:

[0069]

[0070] Add hydrogen storage catalyst Pd (100 mg, 0.5 mol%; Pd supported on Al2O3), 2-methylquinoline (1.43 g, 10 mmol) and dioxane (10 mL) to a 50 mL high-pressure reactor, and cover the reactor.

[0071] The gas inside the high-pressure reactor was replaced six times with hydrogen gas at 1.0 MPa.

[0072] Hydrogen gas was pressurized to 5.0 MPa and subjected to a hydrogenation reaction at 150 °C. After 5 hours of reaction, the hydrogen pressure no longer decreased. The mixture was then cooled to room temperature, the gas was released, and the Pd / Al2O3 and the reaction liquid were separated by filtration. The Pd / Al2O3 catalyst can be recycled.

[0073] Gas chromatography was used to detect the reaction solution, and 2-methylquinoline was completely converted to 2-methyldecahydroquinoline. The reaction solution was then concentrated under vacuum to obtain pure 2-methyldecahydroquinoline with a yield of 98%.

[0074] Example 3

[0075] This embodiment provides a hydrogen storage method, the reaction process of which is as follows:

[0076]

[0077] Add hydrogen storage catalyst Co-NPs (15 mg, 7.5 mol%), 2-methylquinoline (143 mg, 1 mmol) and n-hexane (2 mL) to a 50 mL high-pressure reactor, and cover the reactor.

[0078] The gas inside the high-pressure reactor was replaced six times with hydrogen gas at 1.0 MPa.

[0079] Hydrogen gas is pressurized to 3.0 MPa and subjected to a hydrogenation reaction at 150 °C. After 24 hours of reaction, the hydrogen pressure no longer decreases. The mixture is then cooled to room temperature, the gas is released, and the catalyst and reaction liquid are separated by filtration. The catalyst can be recycled.

[0080] Gas chromatography was used to detect the reaction solution, and 2-methylquinoline (the compound shown in formula Ia) was completely converted into 2-methyldecahydroquinoline (the compound shown in formula IV-a). After vacuum concentration, pure 2-methyldecahydroquinoline was obtained with a yield of 100% and a hydrogen storage capacity of up to 6.53 wt%.

[0081] Example 4

[0082] This embodiment provides a hydrogen storage method, the reaction process of which is as follows:

[0083]

[0084] Add the hydrogen storage catalyst Ru (3.5 g, 0.5 mol%; Ru supported on Al2O3) and 2-methylquinoline (50.5 g, 353 mmol) to a 300 mL high-pressure reactor, and cover the reactor.

[0085] The gas inside the high-pressure reactor was replaced six times with hydrogen gas at 1.0 MPa.

[0086] Hydrogen gas was pressurized to 6.5 MPa and subjected to a hydrogenation reaction at 150 °C. After 2 hours of reaction, the pressure was reduced to 0.4 MPa and the mixture was cooled.

[0087] Add hydrogen to 6.5 MPa and react at 150°C. Add hydrogen every 2 hours for a total of 3 times until the pressure remains constant. After cooling to room temperature, release the gas and filter to separate Ru / Al2O3 and the reaction liquid. The catalyst Ru / Al2O3 can be recycled.

[0088] Gas chromatography was used to detect the reaction solution, and 2-methylquinoline was completely converted to 2-methyldecahydroquinoline. The reaction solution was then concentrated under vacuum to obtain pure 2-methyldecahydroquinoline with a yield of 98%.

[0089] Example 5

[0090] This embodiment provides a hydrogen storage method, the reaction process of which is as follows:

[0091]

[0092] Add the hydrogen storage catalyst Ru (350 mg, 0.5 mol%; Ru supported on Al2O3) and 2-methylquinoline (5.1 g, 35.3 mmol) to a 50 mL high-pressure reactor, and cover the reactor.

[0093] The gas inside the high-pressure reactor was replaced six times with hydrogen gas at 1.0 MPa.

[0094] Hydrogen gas was pressurized to 6.5 MPa and subjected to a hydrogenation reaction at 180 °C. After 1.5 h of reaction, the pressure was reduced to 0.1 MPa and the mixture was cooled.

[0095] Add hydrogen to 6.5 MPa and react at 180 °C. Add hydrogen every 2 hours to ensure that 2-methylquinoline fully absorbs hydrogen, for a total of 2 times, until the pressure remains constant. After cooling to room temperature, release the gas, filter to separate Ru / Al2O3 and the reaction solution. The catalyst Ru / Al2O3 can be recycled.

[0096] Gas chromatography was used to detect the reaction solution, and 2-methylquinoline was completely converted to 2-methyldecahydroquinoline. The reaction solution was then concentrated under vacuum to obtain pure 2-methyldecahydroquinoline with a yield of 100%.

[0097] Example 6

[0098] This embodiment provides a hydrogen storage method, the reaction process of which is as follows:

[0099]

[0100] Add the hydrogen storage catalyst Ru (100 mg, 0.5 mol%; the hydrogen storage catalyst Ru is supported on Al2O3), quinoline (1.29 g, 10 mmol) and n-hexane (2 mL) to a 50 mL high-pressure reactor, and cover the reactor.

[0101] The gas inside the high-pressure reactor was replaced six times with hydrogen gas at 1.0 MPa.

[0102] Hydrogen gas was pressurized to 5.0 MPa and subjected to a hydrogenation reaction at 150 °C for 5 hours. After the hydrogen pressure stopped decreasing, the mixture was cooled to room temperature, the gas was released, and Ru / Al2O3 and the reaction liquid were separated by filtration. The catalyst Ru / Al2O3 can be recycled.

[0103] Gas chromatography was used to detect the reaction solution, and quinoline was completely converted into decahydroquinoline. After vacuum concentration, pure decahydroquinoline was obtained with a yield of 100% and a hydrogen storage capacity of 7.2 wt%.

[0104] Example 7

[0105] This embodiment provides a hydrogen storage method, the reaction process of which is as follows:

[0106]

[0107] Add the hydrogen storage catalyst Ru (100 mg, 0.5 mol%; the hydrogen storage catalyst Ru is supported on Al2O3), quinoline (1.29 g, 10 mmol) and n-hexane (2 mL) to a 50 mL high-pressure reactor, and cover the reactor.

[0108] The gas inside the high-pressure reactor was replaced six times with hydrogen gas at 1.0 MPa.

[0109] Hydrogen gas was pressurized to 5.0 MPa and subjected to a hydrogenation reaction at 80°C for 5 hours. Once the hydrogen pressure no longer decreased, the mixture was cooled to room temperature, the gas was released, and Ru / Al2O3 and the reaction liquid were separated by filtration. The Ru / Al2O3 catalyst can be recycled.

[0110] Gas chromatography was used to detect the reaction solution, and it was found that quinoline had been completely converted to tetrahydroquinoline. After vacuum concentration, pure tetrahydroquinoline was obtained with a yield of 100%.

[0111] Examples 8-17:

[0112] Examples 8-17 provide a method for hydrogen desorption, the reaction process of which is as follows:

[0113]

[0114] Under an argon atmosphere, a dehydrogenation catalyst (1.0 mol%), 2-methyldecahydroquinoline (153 mg, 1 mmol), and xylene (1 mL) were added to a 10 mL Shoelock reaction tube. The mixture was heated to reflux for hydrogenation at 137 °C for 24 h. The reaction was monitored by gas chromatography-mass spectrometry (GC-MS), and the product yield was determined by the internal standard method.

[0115] The only difference between Examples 8-17 is the dehydrogenation catalyst used; all other reaction conditions are the same. The dehydrogenation catalysts used in Examples 8-17 and the corresponding product yields are shown in Table 1.

[0116] Table 1. Catalysts used in Examples 8-17 and corresponding product yields

[0117]

[0118]

[0119] In the above embodiments, Examples 8, 11, 12, 13, and 14 have high conversion rates. Therefore, their corresponding catalyst systems Pd(OAc)2-γ-Al2O3, Pd(OAc)2-CeO2, Pd(OAc)2-T1O2, Pd(OAc)2-AC, and Pd+Pt / AC are preferred dehydrogenation catalysts and catalyst supports for the 2-methyldecahydroquinoline dehydrogenation reaction (i.e., the second support described in this invention).

[0120] Comparing Examples 8-13, it can be seen that the catalytic performance of Pd(OAc)2 supported by γ-Al2O3, CeO2, TiO2, and AC is better than that of Pd(OAc)2 supported by ZnO and SiO2. This may be because the acidity of the support surface affects the dehydrogenation efficiency. Among them, the dehydrogenation catalysts of Pd(OAc)2 supported by CeO2, TiO2, and AC show the best performance.

[0121] Comparing Examples 13 and 17, it can be seen that in this reaction system, the catalytic performance of Pd(OAc)2-AC is better than that of Pd / AC. Comparing Examples 14 and 16 and 17, it can be seen that in this reaction system, the catalytic performance of Pd+Pt / AC is better than that of Pd / AC or Pt / AC alone, indicating that the simultaneous use of Pd and Pt has a synergistic catalytic effect.

[0122] As shown in Table 1, Examples 8-17 of the present invention provide a hydrogen desorption method that can be implemented at a relatively low temperature (137°C). The dehydrogenation process has a mild reaction temperature, which is less likely to cause material decomposition or catalyst deactivation. The present invention further provides a preferred dehydrogenation catalyst in this reaction system. The hydrogen desorption method provided by the present invention has a simple reaction process, low energy consumption, and low equipment requirements.

[0123] Examples 18-27:

[0124] Examples 18-27 provide a method for hydrogen desorption, the reaction process of which is as follows:

[0125]

[0126] Under an argon atmosphere, Pd(OAc)₂ (1.0-2.0 mol%) and a second support (AC, TiO₂, or CeO₂) were added to a 10 mL Shoelock reaction tube, along with 153 mg (1 mmol) of 2-methyldecahydroquinoline and 1 mL of a second solvent. The mixture was then heated to reflux for hydrogenation. The reaction was monitored by gas chromatography-mass spectrometry (GC-MS), and the conversion and product yield were determined using the internal standard method.

[0127] The differences between Examples 18-27 lie in the amount of Pd(OAc)2 used, the type and amount of the second support, the second solvent used, and the temperature and time of the dehydrogenation reaction. The specific reaction conditions and corresponding conversions and yields for Examples 18-27 are shown in Table 2.

[0128] Table 2 shows the specific reaction conditions and corresponding conversion and yield rates for Examples 18-27.

[0129]

[0130] Comparing Examples 18, 19, 20, and 27, it is evident that nonane, dodecane, and trimethylbenzene are preferred solvents in the 2-methyldecahydroquinoline dehydrogenation reaction system. These solvents enable the dehydrogenation of 2-methyldecahydroquinoline to produce hydrogen at relatively low temperatures (151–174°C) with a high conversion rate. Although the system using toluene as a solvent can achieve dehydrogenation at an even lower temperature (110°C), the conversion rate is lower. Among these, trimethylbenzene is a more preferred solvent in the 2-methyldecahydroquinoline dehydrogenation reaction system, enabling the dehydrogenation of 2-methyldecahydroquinoline at 162°C with a higher conversion rate compared to the systems using nonane and dodecane as solvents.

[0131] Comparing Examples 20, 21, and 22, it can be seen that the dehydrogenation reaction system using AC as the catalyst support has a higher conversion rate than the reaction system using TiO2 and CeO2 as the support. This is because activated carbon has a larger specific surface area.

[0132] Comparing Examples 20 and 24, the catalytic performance is better when the mass ratio of Pd(OAc)2 to AC is 1:10 than that of the reaction system with a mass ratio of Pd(OAc)2 to AC of 1:5. This is because excessive palladium content easily leads to agglomeration.

[0133] Comparing Examples 20 and 25, it can be seen that when the molar ratio of Pd(OAc)2 to 2-methyldecahydroquinoline is between 1% and 2%, the conversion rate increases with the increase of this molar ratio.

[0134] As shown in Table 2, this invention further discloses a hydrogen desorption method using nonane, dodecane, and trimethylbenzene as solvents, which can achieve hydrogen desorption at 151–174 °C, solving the problems of material decomposition and catalyst deactivation caused by the higher dehydrogenation temperatures in existing technologies. This invention further discloses that Pd(OAc)₂ and AC exhibit superior catalytic performance as dehydrogenation catalysts. This invention further discloses that the optimal mass ratio of the dehydrogenation catalyst to 2-methyldecahydroquinoline is within the range of 1%–2%, and the conversion rate can be increased by increasing the amount of dehydrogenation catalyst. By controlling the solvent, reaction time, type and amount of dehydrogenation catalyst, the hydrogen desorption method provided by this invention can achieve high conversion rates at lower temperatures, showing promising application prospects.

[0135] Examples 28-37

[0136] Examples 28-37 provide a method for hydrogen desorption, the reaction process of which is as follows:

[0137]

[0138] Under an argon atmosphere, Pd(OAc)₂ (1.0 mol%) and activated carbon (AC, 200 mg) were added to a 10 mL Shoelock reaction tube, followed by 2-methyldecahydroquinoline (1.53 mg, 10 mmol). The reaction was carried out by reflux in an oil bath at 200 °C. Gas chromatography was used to detect the reaction, and the conversion and product yield were determined by internal standard method.

[0139] The only difference between Examples 28-37 is the reaction time; all other reaction conditions are the same. The specific reaction times and corresponding conversion and yields for Examples 28-37 are shown in Table 3.

[0140] Table 3 shows the specific reaction times and corresponding conversion and yields for Examples 28-37.

[0141]

[0142]

[0143] As shown in Table 3, in the dehydrogenation reaction system of 2-methyldecahydroquinoline, under reaction conditions without the use of other solvents, when the reaction temperature is 200℃ and the reaction time is more than 36 hours, the H2 yield reaches more than 80%; when the reaction time reaches 108 hours, the H2 yield can reach more than 90%.

[0144] Examples 38-52

[0145] Examples 38-52 provide a method for hydrogen desorption, the reaction process of which is as follows:

[0146]

[0147] Under an argon atmosphere, Pd(OAc)₂ (1.0 mol%) and activated carbon (AC, 200 mg) were added to a 10 mL Shoelock reaction tube, followed by 2-methyldecahydroquinoline (1.53 mg, 10 mmol). The reaction was carried out by reflux in an oil bath at 180 °C. Gas chromatography was used to detect the reaction, and the conversion and product yield were determined by internal standard method.

[0148] The only difference between Examples 38-52 is the reaction time; all other reaction conditions are the same. The specific reaction times and corresponding conversion and yields for Examples 38-52 are shown in Table 4.

[0149] Table 4 shows the specific reaction times and corresponding conversion and yields for Examples 38-52.

[0150]

[0151] Table 4 shows that in the dehydrogenation reaction system of 2-methyldecahydroquinoline, under reaction conditions without the use of other solvents, at a reaction temperature of 180℃ and a reaction time of 108 h, the H2 yield reaches over 83%; when the reaction time reaches 144 h, the H2 yield can reach over 90%. Referring to Tables 3 and 4, it can be seen that within a certain temperature range, by increasing the reaction temperature, a higher H2 yield can be obtained in a shorter reaction time. The 2-methyldecahydroquinoline dehydrogenation method provided by this invention can achieve a hydrogen conversion rate of over 96%.

[0152] Figure 2 This is the gas chromatogram of the product of Example 39, from... Figure 2 It can be seen that after 24 hours of reaction, most of the 2-methyldecahydroquinoline loses hydrogen and produces the compound shown in formula II.

[0153] Examples 53-65:

[0154] Examples 53-65 provide a method for hydrogen desorption, the reaction process of which is as follows:

[0155]

[0156] Under an argon atmosphere, Pd(OAc)₂ (1.0 mol%) and activated carbon (AC, 200 mg) were added as dehydrogenation catalysts to a 10 mL Shoelock reaction tube, followed by the addition of decahydroquinoline (1.39 mg, 10 mmol). The reaction was carried out under reflux in an oil bath at 180 °C. Gas chromatography was used to detect the reaction, and the conversion and product yield were determined by internal standard method.

[0157] The only difference between Examples 53-65 is the reaction time; all other reaction conditions are the same. The specific reaction times and corresponding conversion and yields for Examples 53-65 are shown in Table 5.

[0158] Table 5 shows the specific reaction times and corresponding conversion and yields for Examples 53-65.

[0159]

[0160] As shown in Table 5, the decahydroquinoline dehydrogenation method provided by the present invention can achieve a hydrogen conversion rate of over 67%.

[0161] Comparing Tables 4 and 5, it can be seen that, under the same temperature and catalyst conditions, compared to the dehydrogenation reaction system of decahydroquinoline, 2-methyldecahydroquinoline can achieve dehydrogenation in a shorter time, and 2-methyldecahydroquinoline can achieve complete conversion, while having a higher H2 yield in the same time. Therefore, this invention discloses a preferred hydrogen desorption method using a material including 2-methyldecahydroquinoline as a hydrogen storage material, which can achieve a higher H2 yield.

[0162] All aspects, embodiments, features, and examples of this invention are to be regarded as illustrative in all respects and are not intended to limit the invention, the scope of which is defined only by the claims. Other embodiments, modifications, and uses will become apparent to those skilled in the art without departing from the spirit and scope of the invention as claimed.

[0163] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0164] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims. Moreover, unless specifically stated otherwise, any use of the terms first, second, etc., does not indicate any order or importance, but is used to distinguish one element from another.

Claims

1. A method for hydrogen desorption, characterized in that, include: A mixed reaction system comprising a material containing hydrogen storage, a dehydrogenation catalyst, and a second solvent is subjected to a dehydrogenation reaction at 151-174°C under a protective atmosphere to obtain a hydrogen storage material and hydrogen; wherein the dehydrogenation catalyst is Pd(OAc)2, the dehydrogenation catalyst is supported on a second support, the second support being AC; and the second solvent is selected from one or more of thiol, nonane, and dodecane. The material storing hydrogen includes the compound shown in Formula IV: ； The hydrogen storage material is a compound of Formula I: 。 2. The hydrogen desorption method according to claim 1, characterized in that: The dehydrogenation reaction time is 1~180 h.

3. The hydrogen desorption method according to claim 1, characterized in that: The molar ratio of the dehydrogenation catalyst to the hydrogen-containing material is 1:5000 to 1:

20.

4. The hydrogen desorption method according to claim 1, characterized in that: The volume ratio of the second solvent to the material containing hydrogen is 20:1 to 0.0001:

1.

5. The hydrogen desorption method according to claim 1, characterized in that: The protective atmosphere includes nitrogen and / or an inert gas.

6. A method for hydrogen storage and desorption, characterized in that, include: In the presence of a hydrogen storage catalyst, the hydrogen storage material of the compound shown in Formula I is brought into contact with a hydrogen-containing gas and subjected to a hydrogenation reaction to obtain a material storing hydrogen. Hydrogen is released from the hydrogen-containing material according to any one of claims 1-5, wherein the hydrogen yield during the hydrogen desorption process is 1-100%.

7. The method according to claim 6, characterized in that: The hydrogen storage catalyst includes one or more of Ru, Pt, Pd and Co-NPs; the hydrogen storage catalyst is supported on a first support, the first support including one or more of Al2O3, AC, TiO2, SiO2, CeO2 and ZnO.

8. The method according to claim 6, characterized in that: The molar ratio of the hydrogen storage catalyst to the hydrogen storage material is 1:5000 to 1:

20.

9. The method according to claim 6, characterized in that: The reaction temperature for the hydrogenation reaction is 80~180℃.

10. The method according to claim 6, characterized in that: The reaction time for the hydrogenation reaction is 0.5 to 24 hours.

11. The method according to claim 6, characterized in that, Specifically, it includes: The hydrogen storage material and the hydrogen storage catalyst are placed in a reaction vessel; the gas in the reaction vessel is replaced with hydrogen-containing gas; and hydrogen-containing gas at a pressure of 0.1 to 8 MPa is introduced into the reaction vessel to carry out the hydrogenation reaction.

12. The method according to claim 11, characterized in that, Specifically, it includes: The hydrogenation reaction is carried out in the reaction vessel by placing the mixed reaction system containing the hydrogen storage material, the hydrogen storage catalyst and the first solvent; the first solvent includes one or more of n-hexane, cyclohexane, n-heptane, tetrahydrofuran and dioxane.

13. The method according to claim 12, characterized in that: The volume ratio of the first solvent to the hydrogen storage material is 10:1 to 0.0001:1, wherein the amount of hydrogen storage material used is greater than zero.

14. The method according to claim 6, characterized in that: The hydrogen-containing gas is hydrogen.

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