阅读说明：本技术 储氢材料以及基于该储氢材料的储放氢方法 (Hydrogen storage material and hydrogen storage and discharge method based on same ) 是由 刘振洁 闫缓 贺挺 于 2021-07-22 设计创作，主要内容包括：本发明提供了一种储氢材料以及基于该储氢材料的储放氢方法,涉及储氢材料技术领域。所述储氢材料主要由7-甲基吲哚10～80wt％、7-乙基吲哚20～90wt％组成。经试验和热力学验证得到,由本申请上述原料制得的有机储氢材料具有储氢量高、储放氢能量损失小、脱氢温度较低的优势,其能量损失低于27％,储氢量不低于5.5wt％,脱氢温度介于120℃-190℃,且加氢、储运氢、脱氢等环节均为液态,进而有效实现了储氢材料脱氢过程与用户端兼容,氢储运在常温常压下运输的技术效果。(The invention provides a hydrogen storage material and a hydrogen storage and discharge method based on the hydrogen storage material, and relates to the technical field of hydrogen storage materials. The hydrogen storage material mainly comprises 10-80 wt% of 7-methylindole and 20-90 wt% of 7-ethylindole. Experiments and thermodynamic verification prove that the organic hydrogen storage material prepared from the raw materials has the advantages of high hydrogen storage capacity, low energy loss of hydrogen storage and low dehydrogenation temperature, the energy loss is lower than 27%, the hydrogen storage capacity is not lower than 5.5 wt%, the dehydrogenation temperature is between 120 ℃ and 190 ℃, and links such as hydrogenation, hydrogen storage and transportation, dehydrogenation and the like are all liquid, so that the technical effects that the dehydrogenation process of the hydrogen storage material is compatible with a user terminal and the hydrogen storage and transportation are carried out at normal temperature and normal pressure are effectively realized.)

1. A hydrogen storage material is characterized in that the hydrogen storage material is mainly obtained by mixing 7-methylindole and 7-ethylindole;

the hydrogen storage material comprises the following components in percentage by mass: 10-80 wt% of 7-methylindole and 20-90 wt% of 7-ethylindole, wherein the sum of the mass percentages of the components in the hydrogen storage material is 100%.

2. A hydrogen storage material as claimed in claim 1, characterized in that it comprises, in mass percent: 40-80 wt% of 7-methylindole and 20-60 wt% of 7-ethylindole, wherein the sum of the mass percentages of the components in the hydrogen storage material is 100%;

preferably, the hydrogen storage material comprises, in mass percent: 80 wt% of 7-methylindole and 20 wt% of 7-ethylindole.

3. A method for the preparation of a hydrogen storage material according to claim 1 or 2, characterized in that the method comprises the steps of:

fully mixing 7-methylindole and 7-ethylindole to obtain a hydrogen storage material;

preferably, the mixing method comprises one or a combination of heating mixing and ultrasonic oscillation mixing.

4. A method for storing hydrogen based on the hydrogen storage material of claim 1 or 2.

5. The hydrogen storage method according to claim 4, comprising the steps of:

(a) and storing hydrogen: uniformly mixing a hydrogen storage material and a noble metal catalyst to obtain a material A; then under the condition of isolating air, the material A and hydrogen gas are subjected to hydrogen storage reaction to obtain a hydrogen-rich material; then, sequentially cooling and carrying out solid-liquid separation to obtain a regenerated solid noble metal catalyst and a liquid hydrogen storage material after storing hydrogen;

(b) and dehydrogenation: and (b) uniformly mixing the liquid hydrogen storage material obtained in the step (a) after hydrogen storage with a noble metal catalyst, heating to the decomposition temperature, and decomposing to obtain the liquid hydrogen storage material after dehydrogenation, a regenerated solid noble metal catalyst and hydrogen.

6. A hydrogen storage and release method as claimed in claim 5, wherein the noble metal catalyst comprises Pd/Al₂O₃、Pt/Al₂O₃、Ru/Al₂O₃、Rh/Al₂O₃At least one of Pd/C, Pt/C, Ru/C and Rh/C;

preferably, the loading amount of the noble metal in the noble metal catalyst is 1-5 wt%.

7. A hydrogen storage and release method as claimed in claim 5, wherein the mass ratio of the hydrogen storage material to the noble metal catalyst in the step (a) is 10-5: 1;

preferably, the mass ratio of the liquid hydrogen storage material after hydrogen storage in the step (b) to the noble metal catalyst is 10-5: 1.

8. A hydrogen storage and discharge method as claimed in claim 5, wherein the air isolation in step (a) is performed by charging nitrogen gas under a pressure of 0.3-1 MPa.

9. A hydrogen storage and release method as claimed in claim 5, wherein the temperature of the hydrogen storage reaction in the step (a) is 120 to 160 ℃, and the pressure is 3 to 7 MPa;

preferably, the hydrogen storage reaction in the step (a) is carried out under the condition of stirring, and the stirring revolution is 600-800 r/min;

preferably, the temperature for reducing the temperature in the step (a) is 22-25 ℃;

preferably, the solid-liquid separation method in step (a) is suction filtration.

10. A hydrogen storage and discharge method as claimed in claim 5, wherein the decomposition temperature in the step (b) is 120 to 190 ℃;

preferably, the step (b) decomposition is carried out under stirring, and the rotation speed of the stirring is 500-.

Technical Field

The invention relates to the technical field of hydrogen storage materials, in particular to a hydrogen storage material and a hydrogen storage and release method based on the hydrogen storage material.

Background

The main hydrogen storage technologies at present are high-pressure hydrogen storage and low-temperature liquefied hydrogen storage, and both the two hydrogen storage modes have non-negligible technical defects. The high-pressure hydrogen storage has the advantages of simplicity, common use and disadvantages of low volume energy density, high requirement on the pressure resistance of a container, insecurity and time-consuming hydrogenation link; although the low-temperature liquefied hydrogen storage has high volume energy density, the low-temperature liquefied hydrogen storage has large liquefaction energy consumption, large evaporation loss, high requirements on storage tank heat-insulating materials and accessory equipment, high manufacturing cost and poor economic competitiveness.

The organic liquid hydrogen storage technology can solve the defects of the two hydrogen storage modes to a certain extent. The organic liquid hydrogen storage technology is to store hydrogen atoms in unsaturated aromatic hydrocarbons to form hydrogen-rich compounds in a chemical mode, so that a pair of hydrogen-poor/hydrogen-rich reversible compounds realizes the hydrogen storage and release capacity. Related hydrogen storage carriers related to organic liquid hydrogen storage technology, such as carbazole hydrogen storage molecules, which are reported previously, have high melting points which are above 60 ℃ (e.g. N-ethylcarbazole melting point 68 ℃), are solid at normal temperature, and are not convenient to store and transport like liquid. Even if the organic hydrogen storage material is brought into a liquid state by compounding or adding a solvent, etc., this brings about various problems such as complexity of material components, increased risk of uncontrollable occurrence of side reactions, and reduced mass hydrogen storage density of the hydrogen storage material. Non-nitrogen heterocyclic organic hydrogen storage carriers such as toluene and benzyl toluene molecules are liquid at normal temperature and normal pressure, but the dehydrogenation temperature of the non-nitrogen heterocyclic organic hydrogen storage carriers is higher and is over 240 ℃, so that the energy consumption for storing and releasing hydrogen is too high, and the non-nitrogen heterocyclic organic hydrogen storage carriers cannot be accepted by end users in practical application.

Therefore, research and development of an organic hydrogen storage material which has high hydrogen storage capacity, small energy loss of hydrogen storage and storage, lower dehydrogenation temperature, liquid hydrogenation, hydrogen storage and transportation, dehydrogenation and other links are realized, so that the dehydrogenation process is compatible with a user side, and the hydrogen storage and transportation are carried out at normal temperature and normal pressure, which becomes necessary and urgent.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The first purpose of the invention is to provide a hydrogen storage material, which mainly comprises 10-80 wt% of 7-methylindole and 20-90 wt% of 7-ethylindole. Experiments and thermodynamic verification prove that the organic hydrogen storage material prepared from the raw materials has the advantages of high hydrogen storage capacity, small loss of hydrogen storage energy and low dehydrogenation temperature.

The second purpose of the invention is to provide a preparation method of hydrogen storage material, which has the advantages of simple process and easy operation.

The third purpose of the invention is to provide a hydrogen storage and discharge method, which is realized based on the hydrogen storage material.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

the hydrogen storage material provided by the invention is mainly obtained by mixing 7-methylindole and 7-ethylindole;

the hydrogen storage material comprises the following components in percentage by mass: 10-80 wt% of 7-methylindole and 20-90 wt% of 7-ethylindole, wherein the sum of the mass percentages of the components in the hydrogen storage material is 100%.

Further, the hydrogen storage material comprises the following components in percentage by mass: 40-80 wt% of 7-methylindole and 20-60 wt% of 7-ethylindole, wherein the sum of the mass percentages of the components in the hydrogen storage material is 100%;

preferably, the hydrogen storage material comprises, in mass percent: 80 wt% of 7-methylindole and 20 wt% of 7-ethylindole.

The invention provides a preparation method of the hydrogen storage material, which comprises the following steps:

fully mixing 7-methylindole and 7-ethylindole to obtain a hydrogen storage material;

preferably, the mixing method comprises one or a combination of heating mixing and ultrasonic oscillation mixing.

The invention provides a hydrogen storage and discharge method based on the hydrogen storage material.

Further, the hydrogen storage and release method comprises the following steps:

(a) and storing hydrogen: uniformly mixing a hydrogen storage material and a noble metal catalyst to obtain a material A, and then carrying out hydrogen storage reaction on the material A and hydrogen under the condition of isolating air to obtain a hydrogen-rich material; then, sequentially cooling and carrying out solid-liquid separation to obtain a regenerated solid noble metal catalyst and a liquid hydrogen storage material after storing hydrogen;

(b) and dehydrogenation: and (b) uniformly mixing the liquid hydrogen storage material obtained in the step (a) after hydrogen storage with a noble metal catalyst, heating to the decomposition temperature, and decomposing to obtain the liquid hydrogen storage material after dehydrogenation, a regenerated solid noble metal catalyst and hydrogen.

Further, the noble metal catalyst comprises Pd/Al₂O₃、Pt/Al₂O₃、Ru/Al₂O₃、Rh/Al₂O₃At least one of Pd/C, Pt/C, Ru/C and Rh/C;

preferably, the loading amount of the noble metal in the noble metal catalyst is 1-5 wt%.

Further, the mass ratio of the hydrogen storage material to the noble metal catalyst in the step (a) is 10-5: 1;

preferably, the mass ratio of the liquid hydrogen storage material after hydrogen storage in the step (b) to the noble metal catalyst is 10-5: 1.

Further, the method for isolating air in the step (a) is to fill nitrogen under the pressure of 0.3-1 Mpa.

Further, the temperature of the hydrogen storage reaction in the step (a) is 120-160 ℃, and the pressure is 3-7 Mpa;

preferably, the hydrogen storage reaction in the step (a) is carried out under the condition of stirring, and the stirring revolution is 600-800 r/min;

preferably, the temperature for reducing the temperature in the step (a) is 22-25 ℃;

preferably, the solid-liquid separation method in step (a) is suction filtration.

Further, the decomposition temperature of the step (b) is 120-190 ℃;

preferably, the step (b) decomposition is carried out under stirring, and the rotation speed of the stirring is 500-.

Compared with the prior art, the invention has the beneficial effects that:

the hydrogen storage material provided by the invention mainly comprises 10-80 wt% of 7-methylindole and 20-90 wt% of 7-ethylindole. Experiments and thermodynamic verification prove that the organic hydrogen storage material prepared from the raw materials has the advantages of high hydrogen storage capacity, low energy loss of hydrogen storage and low dehydrogenation temperature, the energy loss is lower than 27%, the hydrogen storage capacity is not lower than 5.5 wt%, the dehydrogenation temperature is between 120 ℃ and 190 ℃, and links such as hydrogenation, hydrogen storage and transportation, dehydrogenation and the like are all liquid, so that the technical effects that the dehydrogenation process of the hydrogen storage material is compatible with a user terminal and the hydrogen storage and transportation are carried out at normal temperature and normal pressure are effectively realized.

The preparation method of the hydrogen storage material provided by the invention comprises the steps of fully mixing 7-methylindole and 7-ethylindole to obtain the hydrogen storage material; the preparation method has the advantages of simple process and easy operation.

The hydrogen storage and release method provided by the invention is realized based on the hydrogen storage material and is determined by the characteristics of the hydrogen storage material, the hydrogen storage and release method has the advantages of small energy loss of hydrogen storage and release and low dehydrogenation temperature, the energy loss in the hydrogen storage and release process is lower than 22-27%, and the dehydrogenation temperature in the dehydrogenation stage is lower than 190 ℃.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a comparison of catalytic performance of different types of catalysts provided herein;

FIG. 2 is a graph showing the hydrogen adsorption amount of the hydrogen storage material according to the present invention at different temperatures according to the superimposed curves of the time-dependent change;

FIG. 3 is a graph showing the comparative curves of hydrogen storage performance of the hydrogen storage material of the present invention at different pressures according to examples 22 to 25 of the present invention;

FIG. 4 is a superimposed graph of the hydrogen release amount of the hydrogen storage material of the present application at different temperatures according to the variation with time, provided in examples 26 to 32 of the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

According to one aspect of the present invention, a hydrogen storage material is obtained by mixing 7-methylindole and 7-ethylindole;

the hydrogen storage material comprises the following components in percentage by mass: 10-80 wt% of 7-methylindole and 20-90 wt% of 7-ethylindole, wherein the sum of the mass percentages of the components in the hydrogen storage material is 100%.

The hydrogen storage material provided by the invention mainly comprises 10-80 wt% of 7-methylindole and 20-90 wt% of 7-ethylindole. Experiments and thermodynamic verification prove that the organic hydrogen storage material prepared from the raw materials has the advantages of high hydrogen storage capacity, low energy loss of hydrogen storage and low dehydrogenation temperature, the energy loss is lower than 27%, the hydrogen storage capacity is not lower than 5.5 wt%, the dehydrogenation temperature is between 120 ℃ and 190 ℃, and links such as hydrogenation, hydrogen storage and transportation, dehydrogenation and the like are all liquid, so that the technical effects that the dehydrogenation process of the hydrogen storage material is compatible with a user terminal and the hydrogen storage and transportation are carried out at normal temperature and normal pressure are effectively realized.

Specifically, the chemical reaction equation for charging and discharging hydrogen of the hydrogen storage material is as follows:

it should be noted that, in the hydrogen storage material screening stage, the organic liquid hydrogen storage technology is considered to be a chemical hydrogen storage mode, so that whether the hydrogen storage molecule has feasibility or not needs to be considered from the thermodynamic viewpoint, and the energy loss should be as small as possible. The organic liquid hydrogen storage materials 7-methylindole (7-MID) and 7-ethylindole (7-EID) developed in the present invention have less energy loss by calculation. Firstly, thermodynamic calculation is carried out on a hydrogenation and dehydrogenation reversible process based on 7-methylindole and 7-ethylindole, meanwhile, the hydrogenation and dehydrogenation processes are independently completed by combining practical application conditions, and energy balance calculation is carried out on the premise that heat exchange does not exist in the two processes. The results of the hydrogenation and dehydrogenation process calculations are shown in tables 1 and 2, respectively.

Table 1 hydrogenation process energy calculation results:

molecule	Hydrogenation conditions	Heating of delta T	Pressurized delta P	Enthalpy of reaction	Energy exchange
						7-MID	150℃ 7MPa	+1.1	+3.77	-7.32	-2.45
7-EID	150℃ 7MPa	+1.52	+3.77	-7.34	-2.05

Table 2 dehydrogenation process energy calculation results:

note: all units in the above tables are kWh/KgH₂The energy loss is measured by 33.3kWh energy of 1kg hydrogen gas, "+" indicates energy required to be supplied to the system from the outside, and "-" indicates energy released to the outside from the system.

From the above thermodynamic experiments, it can be seen that the hydrogenation process is actually an exothermic reaction, and the residual heat can be recycled except for the energy (mechanical efficiency of 0.75) for maintaining the temperature and pressure required by the reaction, so the hydrogenation process does not consider the energy loss. The dehydrogenation process is endothermic, a large amount of heat is consumed to maintain the reaction, and the energy loss of the dehydrogenation process is 22-27 percent (relative to 1 KgH)₂The energy of (c).

Energy exchange in the hydrogenation process is Q (Δ T) + Q (Δ P) + Δ H;

dehydrogenation process energy exchange ═ Δ H + Q (Δ T);

note: the dehydrogenation process is normal pressure;

the energy loss of the organic liquid hydrogen storage technology based on Methylcyclohexane (MCH) previously published in Kyowa of Japan is 35%.

The energy calculation method of the hydrogen storage system comprises the following steps:

LOHC+nH₂＝LOHC*nH₂pressurizing and heating;

1. the energy output to the outside of the system by the hydrogenation reaction is the delta H of the reaction;

the calculation method of the delta H is that the total energy of the product-the total energy of the reactant is calculated by theoretical calculation software to obtain the energy of each substance participating in the reaction, and then the delta H is calculated.

2. The hydrogen and the carrier are heated to the temperature required by the reaction, and parameters required are the specific heat capacity at constant pressure of the hydrogen and the specific heat capacity at constant pressure of the carrier.

The calculation results of the two numerical values in the step 1 are output and can be directly used.

This part of the energy is the energy that needs to be input into the system.

3. The required pressure for maintaining hydrogen requires hydrogen compression, the power consumption calculation relates to the gas compression principle, and considering that the energy of the outlet gas temperature is negligible and the mechanical efficiency of the compressor is taken as eta equal to 0.75 when the non-staged compression and the low pressure are not high.

Wherein k is a gas adiabatic index, and the gas adiabatic indexes of diatomic molecules are all 1.4;

this part of the energy is the energy that needs to be input into the system.

Heat exchange of the final hydrogenation reaction:

Q·＝·ΔH·+·Q·Δ(T)+·Q·Δ(P)；

4. and (3) dehydrogenation: because of the normal-pressure endothermic reaction, only energy is input into the system, and the input energy is divided into two parts:

one is Δ H for reversible reactions and the other is the temperature Q Δ (T) required to maintain the reaction

The deltah is calculated in the hydrogenation reaction for direct use,

cp2 herein is the specific heat capacity at constant pressure of the perhydrogenated product

Energy exchange of the final dehydrogenation process: q ═ Δ H · + · Q Δ (T)

In a preferred embodiment of the present invention, the hydrogen storage material comprises, in mass percent: 40-80 wt% of 7-methylindole and 20-60 wt% of 7-ethylindole, wherein the sum of the mass percentages of the components in the hydrogen storage material is 100%;

preferably, the hydrogen storage material comprises, in mass percent: 80 wt% of 7-methylindole and 20 wt% of 7-ethylindole.

In the invention, the technical effect of the hydrogen storage material is further optimized by further adjusting and optimizing the dosage proportion of the raw materials of each component.

According to an aspect of the present invention, a method for preparing the above hydrogen storage material, the method comprising the steps of:

fully mixing 7-methylindole and 7-ethylindole to obtain a hydrogen storage material;

the preparation method of the hydrogen storage material provided by the invention comprises the steps of fully mixing 7-methylindole and 7-ethylindole to obtain the hydrogen storage material; the preparation method has the advantages of simple process and easy operation.

In a preferred embodiment of the present invention, the mixing method comprises one or a combination of heating mixing and ultrasonic agitation mixing.

In a preferred embodiment, the time for the heating mixing or the ultrasonic vibration mixing is 5 to 90 min.

According to one aspect of the invention, a method of storing hydrogen is based on the above hydrogen storage material.

The hydrogen storage and release method provided by the invention is realized based on the hydrogen storage material and is determined by the characteristics of the hydrogen storage material, the hydrogen storage and release method has the advantages of small energy loss of hydrogen storage and release and low dehydrogenation temperature, the energy loss in the hydrogen storage and release process is lower than 22-27%, and the dehydrogenation temperature in the dehydrogenation stage is lower than 190 ℃.

In a preferred embodiment of the present invention, the hydrogen storage and release method comprises the following steps:

(a) and storing hydrogen: uniformly mixing a hydrogen storage material and a noble metal catalyst to obtain a material A, and then carrying out hydrogen storage reaction on the material A and hydrogen under the condition of isolating air to obtain a hydrogen-rich material; then, sequentially cooling and carrying out solid-liquid separation to obtain a regenerated solid noble metal catalyst and a liquid hydrogen storage material after storing hydrogen;

(b) and dehydrogenation: and (b) uniformly mixing the liquid hydrogen storage material obtained in the step (a) after hydrogen storage with a noble metal catalyst, heating to the decomposition temperature, and decomposing to obtain the liquid hydrogen storage material after dehydrogenation, a regenerated solid noble metal catalyst and hydrogen.

As a preferred embodiment, the hydrogen storage and release method does not need to add other liquid solvents or additives in all the hydrogenation and dehydrogenation links, and the components of the hydrogen storage material are simple in structure, so that the risk of side reactions is reduced, and the use convenience is improved; the hydrogenation and dehydrogenation conditions are mild, the catalyst is not poisoned and loses activity in the reaction process, and the catalyst can be recycled.

Based on the above technical effects, the applicable scenarios of the hydrogen storage and discharge method of the present application include:

based on the advantages of the above technology, the application scenarios of the technical scheme are rich and diverse, and specifically, the following application scenarios can be seen:

(1) the organic liquid hydrogen storage material has high volume energy storage density and mass energy storage density, is not limited by regions, can play an important role in the field of large-scale energy storage, can be used for a renewable energy power generation system, solves the grid connection problem of unstable electric energy (wind energy, solar energy, tidal energy and other electricity generation capacities are discontinuous), and realizes peak clipping and valley filling of the electric energy. The unstable renewable energy sources are converted into hydrogen energy to be transported on a large scale without being limited by regions, climates and environments. The hydrogen-rich organic liquid hydrogen storage material can also be transported to a use end such as coal-based natural gas for utilization. The liquid organic hydrogen storage material is used for wind power generation, photoelectric hydrogen production and liquid form storage, stored energy is transmitted to a client terminal by utilizing the existing fuel oil transportation mode, and the problems of wind energy and solar energy storage and transmission can be effectively solved.

(2) The hydrogen-rich organic liquid after hydrogenation is matched with a special hydrogen supply device as same as gasoline by using the organic liquid hydrogen storage material as a hydrogen source fuel of large-scale transportation vehicles such as rail transit, ships and the like, and devices utilizing a fuel cell power system are directly hydrogenated by each hydrogenation station to serve as a hydrogen source. The system can make full use of the existing oil and gas energy transportation and refueling system infrastructure, and can be directly used only by slightly modifying, so that a large amount of infrastructure construction cost is saved, the hydrogenation time is short, and the system is safe, efficient and rapid.

Preferably, the step (a) storing hydrogen comprises the steps of:

(1) accurately weighing 7-methylindole and 7-ethylindole with certain mass according to a proportion, and adding the 7-methylindole and the 7-ethylindole into a container; or heating or ultrasonically vibrating to fully mix and dissolve the two;

(2) accurately weighing the mixed solution and the catalyst in a corresponding mass ratio, and placing the mixed solution and the catalyst in a reaction kettle;

(3) the reaction kettle is installed and connected with the pressure sensor, the temperature sensor and the cooling water electromagnetic valve; filling a proper amount of nitrogen into the reaction kettle, emptying again, and circulating for several times to empty the air in the reaction kettle;

(4) setting specific reaction pressure, temperature and rotating speed, raising the hydrogen pressure to a set value after the temperature is raised to the reaction temperature by a program, and starting the reaction; stopping the reaction when the reactants are completely converted into hydrogen-rich products, setting the temperature to 25 ℃ at the moment, and cooling;

(5) and carrying out suction filtration to separate solid-liquid components, and collecting liquid-phase hydrogen-rich organic liquid and solid-state catalyst.

Preferably, the step (b) storing hydrogen comprises the steps of:

(1) accurately weighing hydrogen-rich organic liquid and a catalyst and placing the hydrogen-rich organic liquid and the catalyst in a dehydrogenation reactor;

(2) the reactor is installed and fixed in the constant temperature control heater;

(3) setting constant temperature reaction temperature and stirring speed, and starting reaction after the temperature reaches a set value to prepare pure hydrogen.

In a preferred embodiment of the present invention, the noble metal catalyst comprises Pd/Al₂O₃、Pt/Al₂O₃、Ru/Al₂O₃、Rh/Al₂O₃At least one of Pd/C, Pt/C, Ru/C and Rh/C;

the loading amount of the noble metal in the noble metal catalyst is 1-5 wt%.

In a preferred embodiment of the invention, the mass ratio of the hydrogen storage material to the noble metal catalyst in the step (a) is 10-5: 1;

preferably, the mass ratio of the liquid hydrogen storage material after hydrogen storage in the step (b) to the noble metal catalyst is 10-5: 1.

In a preferred embodiment, the mass ratio of the hydrogen storage material to the noble metal catalyst is adjusted to achieve the largest possible catalytic effect by using the smallest amount of the noble metal catalyst.

In a preferred embodiment of the present invention, the air isolation in step (a) is performed by filling nitrogen gas under a pressure of 0.3 to 1 Mpa.

In a preferred embodiment of the present invention, the temperature of the hydrogen storage reaction in step (a) is 120 to 160 ℃, and the pressure is 3 to 7 Mpa;

as a preferred embodiment, the process parameters of the hydrogen storage reaction are process parameters that are as mild as possible to achieve the final process effect, the given process parameters are specific ranges that can achieve the process effect, the parameters are lower than the given ranges and cannot achieve the effect, and the parameters are higher than the ranges, such as temperature and pressure, which can damage the molecular structure and cause ring breakage, and cannot achieve the effect of reversible hydrogen storage and release.

In a preferred embodiment of the present invention, the hydrogen storage reaction in step (a) is performed under stirring, and the stirring rotation number is 600 to 800 r/min;

in a preferred embodiment of the present invention, the temperature for reducing temperature in the step (a) is 22 to 25 ℃;

in a preferred embodiment of the present invention, the solid-liquid separation method in step (a) is suction filtration.

In a preferred embodiment of the present invention, the decomposition temperature in the step (b) is 120 to 190 ℃; the decomposition is carried out under the condition of stirring, and the rotation speed of the stirring is 500-800 r/min.

As a preferable embodiment, the decomposition temperature of the hydrogen is only 120-190 ℃, and the hydrogen dehydrogenation method has the technical advantage of mild dehydrogenation conditions.

The technical solution of the present invention will be further described with reference to the following examples.

Examples 1 to 8

A hydrogen storage material comprising, in mass percent:

group of	7-methylindole wt.%	7-Ethyl indole wt.%
			Example 1	10	90
Example 2	20	80
			Example 3	30	70
Example 4	40	60
			Example 5	50	50
Example 6	60	40
			Example 7	70	30
Example 8	80	20

The preparation method of the hydrogen storage material comprises the following steps:

(1) accurately weighing 7-methylindole and 7-ethylindole;

(2) heating or ultrasonic or the combination of the two materials to fully mix the two materials;

(3) standing for 30-120 min to ensure no solid precipitation and obtain the hydrogen storage material.

Examples 9 to 16

A hydrogen storage method, comprising the steps of:

the method for preparing the hydrogen-rich organic liquid by using the liquid material comprises the following steps:

(1) accurately weighing 5g of the hydrogen storage material liquid prepared in the embodiment 1-8 and a catalyst, and placing the hydrogen storage material liquid and the catalyst in a reaction kettle;

(2) the reaction kettle is installed and connected with the pressure sensor, the temperature sensor and the cooling water electromagnetic valve;

(3) filling a proper amount of nitrogen into the reaction kettle, emptying, and circulating for several times to empty the air in the reaction kettle;

the times of charging nitrogen and discharging air are 4 times, and the pressure is 0.3-1 MPa;

(4) setting specific reaction pressure, temperature and rotating speed, raising the hydrogen pressure to a set value after the temperature is raised to the reaction temperature by a program, and starting the reaction;

the reaction pressure is 4MPa, the temperature is 170 ℃, and the revolution is 700 r/m;

(5) stopping the reaction when the reactants are completely converted into hydrogen-rich products, setting the temperature to 25 ℃ at the moment, and cooling;

(6) and carrying out suction filtration to separate solid-liquid components, and collecting liquid-phase hydrogen-rich organic liquid and solid-state catalyst.

After the hydrogen storage, the hydrogen storage amount and the melting point of the hydrogen storage materials of examples 1 to 8 are as follows:

the dehydrogenation link of the hydrogen-rich organic liquid comprises the following steps:

(1) accurately weighing 5g of hydrogen-rich organic liquid and a catalyst, and placing the hydrogen-rich organic liquid and the catalyst in a dehydrogenation reactor;

(2) setting up a dehydrogenation reaction device, and fixing a reactor in a constant temperature control heater;

(3) setting the constant temperature reaction temperature of 190 ℃ and the stirring speed of 600 rpm, and starting the reaction after the temperature reaches a set value to prepare pure hydrogen.

FIG. 1 is a comparison of catalytic performance of different types of catalysts. As can be seen from FIG. 1, according to the test results of different types of catalysts, all types of catalysts have catalytic hydrogen storage performance for the material in the reaction within 60 minutes, and the types of the catalysts can be reasonably selected according to the cost and performance of the catalysts, and are only different in strength.

Examples 17 to 21

This example is the same as example 9 except that the "reaction temperature" in the step (i) and (4) is different from that in example 9, and the following details are given:

FIG. 2 is a superimposed graph of hydrogen adsorption capacity versus time at different temperatures for the hydrogen storage material of the present application.

As can be seen from fig. 2, the hydrogen adsorption rate gradually increases with an increase in temperature within the set temperature range. When the temperature rises to a certain value of 160 ℃, the reaction rate basically has no great change and basically has little difference with 150 ℃, and the reason for the result is that the hydrogenation reaction is an endothermic reaction, and when the temperature rises too high, the judgment according to the Lexhlet's series principle is unfavorable for the reaction to proceed to the right, and the inhibition effect is exerted on the forward reaction. At 130 deg.C, the hydrogen absorption rate is slow, and it may be that the temperature does not reach the activation temperature required by the reaction completely, so that the hydrogenation can not be performed quickly. The complete hydrogenation means that one hydrogen storage molecule can be added with four hydrogen molecules, and when all the hydrogen storage molecules are completely hydrogenated, 100 percent of complete hydrogenation can be realized to reach the theoretical hydrogen storage amount. As is clear from the graph, the hydrogen storage material can reach the theoretical hydrogen adsorption amount (5.389 wt%) within 60 minutes at 150 ℃. 100% hydrogenation was achieved completely even at 130 ℃ in 120 minutes, indicating that the hydrogen storage material also has faster hydrogenation kinetics under relatively mild conditions.

Examples 22 to 25

This example is the same as example 9 except that the "reaction pressure" in the step (i) and (4) is different from example 9, and the following details are as follows:

FIG. 3 is a graph showing the superposition of hydrogen storage performance comparison curves of the hydrogen storage material of the present application at different pressures.

As can be seen from fig. 3, the different pressures did not differ much from the hydrogenation rates of the hydrogen storage material, and 100% hydrogenation was achieved in 60 minutes. However, as the hydrogen pressure increases, the rate of the hydrogenation reaction increases only slightly, and the reason for this result may be that the hydrogenation reaction is mainly a reaction between a liquid-solid interface, and the hydrogen pressure mainly affects mass transfer between a gas-liquid phase, and the mass transfer resistance is negligible, so that the change of the reaction rate is less affected by the increase of the hydrogen pressure. (since the influence of the pressure on the hydrogen storage material is limited, the hydrogen pressure test of 3-6 MPa shows that the hydrogen pressure test of 7MPa is not carried out at a higher pressure)

Examples 26 to 32

This example is the same as example 9 except that the "decomposition temperature" in the second step (3) is different from that in example 9, and the following details are as follows:

FIG. 4 is a graph showing the overlay of hydrogen evolution versus time for hydrogen storage materials of the present application at various temperatures.

As can be seen from fig. 4, the hydrogen release rate is gradually increased with the gradual increase of the temperature, which shows that the temperature has a certain promotion effect on the dehydrogenation effect, and the rapid hydrogen release can be realized below 190 ℃.

Example 33

This example is the same as example 9 except that 5g of the solvent "mesitylene" was added in the second step (3).

The effect of the addition of solvent on the hydrogen evolution performance is as follows:

whether the added solvent has an influence on the hydrogen release performance:

with or without solvent	Amount of catalyst used	Reaction time	Conversion rate
				Is provided with	0.5g	4h	95.3％
Is free of	0.5g	4h	94.5％

It is demonstrated that the addition of solvent does not substantially affect the hydrogen release performance, so that the addition of solvent is not necessary for dehydrogenation, but rather the addition of solvent reduces the mass hydrogen storage density of the material.

Comparative examples 1 to 3

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.