阅读说明：本技术 单甲基喹喔啉类化合物的应用及其制备方法、单甲基喹喔啉类化合物的加氢方法及脱氢方法 (Application of monomethyl quinoxaline compound, preparation method thereof, hydrogenation method and dehydrogenation method of monomethyl quinoxaline compound ) 是由 闫缓 刘振洁 贺挺 于 2021-07-29 设计创作，主要内容包括：本发明提供了一种单甲基喹喔啉类化合物的应用及其制备方法、单甲基喹喔啉类化合物的加氢方法及脱氢方法,涉及储氢材料的技术领域。本发明将单甲基喹喔啉类化合物应用在储氢材料中,可在常温常压下进行液态储氢,无需构建低共熔体系,从而减少了加氢或脱氢过程中的副产物,增加了储氢材料使用寿命；同时,本发明的单甲基喹喔啉类化合物应用在储氢材料中,解决了储氢材料热力学能耗高、储氢材料的储氢密度低且氢化之后脱氢温度高的技术问题,达到了低热力学能耗、高质量储氢密度及氢化之后脱氢温度低的技术效果,进一步提升了能量的利用率。本发明提供的单甲基喹喔啉类化合物的加氢方法及脱氢方法具有安全、高效以及便捷的特点。(The invention provides application and a preparation method of a monomethyl quinoxaline compound, a hydrogenation method and a dehydrogenation method of the monomethyl quinoxaline compound, and relates to the technical field of hydrogen storage materials. The monomethyl quinoxaline compound is applied to the hydrogen storage material, and can carry out liquid hydrogen storage at normal temperature and normal pressure without constructing a eutectic system, thereby reducing byproducts in the hydrogenation or dehydrogenation process and prolonging the service life of the hydrogen storage material; meanwhile, the monomethyl quinoxaline compound disclosed by the invention is applied to the hydrogen storage material, so that the technical problems of high thermodynamic energy consumption of the hydrogen storage material, low hydrogen storage density of the hydrogen storage material and high dehydrogenation temperature after hydrogenation are solved, the technical effects of low thermodynamic energy consumption, high quality hydrogen storage density and low dehydrogenation temperature after hydrogenation are achieved, and the utilization rate of energy is further improved. The hydrogenation method and the dehydrogenation method of the monomethyl quinoxaline compound provided by the invention have the characteristics of safety, high efficiency and convenience.)

1. Application of monomethyl quinoxaline compound in hydrogen storage material.

2. The use according to claim 1, characterized in that the monomethylquinoxalines comprise at least one of the following compounds:

preferably, the monomethyl quinoxaline compound is a combination of any two or three.

3. A preparation method of monomethyl quinoxaline compound is characterized by comprising the following steps:

mixing monomethyl quinoxaline compounds according to a ratio to obtain the monomethyl quinoxaline compounds;

the mixing method comprises ultrasonic oscillation or stirring.

4. A hydrogenation method of monomethyl quinoxaline compound is characterized by comprising the following steps:

the monomethyl quinoxaline compound and hydrogen are subjected to hydrogenation reaction under the action of a hydrogenation catalyst to obtain a fully hydrogenated compound.

5. The hydrogenation process of claim 4, wherein the hydrogenation catalyst comprises Ru/Al₂O₃、Pd/Al₂O₃、Pt/Al₂O₃、Rh/Al₂O₃Ru/C, Pd/C, Pt/C and Rh/C.

6. The hydrogenation method according to claim 4, wherein the hydrogenation temperature is 150 to 200 ℃ and the hydrogenation pressure is 5 to 8 MPa;

preferably, the hydrogenation temperature is 190 ℃ and the hydrogenation pressure is 7 MPa.

7. The hydrogenation method according to claim 4, wherein the hydrogenation rotation speed is 300 to 800 r/min;

preferably, the hydrogenation rotation speed is 500 r/min.

8. A dehydrogenation method of monomethyl quinoxaline compounds is characterized by comprising the following steps:

the monomethyl quinoxaline compound and hydrogen are subjected to hydrogenation reaction under the action of a hydrogenation catalyst to obtain a fully hydrogenated compound;

and carrying out dehydrogenation reaction on the fully hydrogenated compound under the action of a dehydrogenation catalyst to obtain hydrogen.

9. The dehydrogenation process of claim 8, wherein the dehydrogenation process is carried out in the presence of a catalystThe dehydrogenation catalyst comprises Ru/Al₂O₃、Pd/Al₂O₃、Pt/Al₂O₃、Rh/Al₂O₃Ru/C, Pd/C, Pt/C and Rh/C.

10. The dehydrogenation process of claim 8, wherein the dehydrogenation temperature is from 150 ℃ to 200 ℃;

preferably, the dehydrogenation rotating speed is 500-800 r/min.

Technical Field

The invention relates to the technical field of hydrogen storage materials, in particular to application and a preparation method of a monomethyl quinoxaline compound, a hydrogenation method and a dehydrogenation method of the monomethyl quinoxaline compound.

Background

The storage and transportation of hydrogen energy is mainly divided into high-pressure hydrogen and liquid hydrogen. The high-pressure hydrogen storage and transportation are widely applied at home, but the hydrogen storage density is low and the safety performance is poor; liquid hydrogen is widely applied abroad, but the liquefaction energy consumption is large, the liquid hydrogen still vaporizes in transportation, and the hydrogen needs to be discharged for pressure relief, so that the safety performance needs to be improved. The liquid organic hydrogen storage can realize hydrogen storage and transportation at normal temperature and normal pressure, has the advantages of safety, high efficiency and convenience, and is an important development direction of hydrogen storage and transportation in the future.

Currently, there are two main types of hydrogen storage materials that are most widely used: the first is benzyl toluenes, toluenes; the second group is nitrogen-containing fused heterocyclic aromatic compounds. The first type of hydrogen storage material has high thermodynamic energy consumption for addition and dehydrogenation, the dehydrogenation temperature is higher and is more than 300 ℃, and the method is difficult to implement in practical application, especially in mobile application; the thermodynamic energy consumption of the second hydrogen storage material during the addition and dehydrogenation is relatively reduced, the dehydrogenation temperature is relatively low and is about 200 ℃ mostly, and the method has obvious advantages in practical application. However, the nitrogen-containing fused heterocyclic aromatic compound mainly comprises carbazole and derivatives thereof, including N-ethyl carbazole and N-propyl carbazole, which are solid at normal temperature and pressure, and thus practical use is limited, so that the two substances or a newly added low-melting-point substance is required to form a eutectic mixture, and thus, the actual hydrogen storage density is reduced, generally about 5.5 wt%, and the increase of the types of the substances of the system is likely to cause the increase of byproducts in the addition and dehydrogenation processes, thereby reducing the service life of the hydrogen storage material.

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

Disclosure of Invention

One of the purposes of the invention is to provide application of monomethyl quinoxaline compounds in hydrogen storage materials, and solve the technical problems of high thermodynamic energy consumption, low hydrogen storage density and high dehydrogenation temperature after hydrogenation of the hydrogen storage materials.

The second purpose of the invention is to provide a preparation method of monomethyl quinoxaline compound.

The invention also aims to provide a hydrogenation method of the monomethyl quinoxaline compound.

The fourth purpose of the invention is to provide a dehydrogenation method of monomethyl quinoxaline compound.

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

in a first aspect, the invention provides an application of monomethyl quinoxaline compounds in hydrogen storage materials.

Further, the monomethyl quinoxaline compound comprises at least one of the following compounds:

further preferably, the monomethyl quinoxaline compound is a combination of any two or three.

In a second aspect, the invention provides a preparation method of monomethyl quinoxaline compounds, which comprises the following steps:

mixing monomethyl quinoxaline compounds according to a ratio to obtain the monomethyl quinoxaline compounds;

the mixing method comprises ultrasonic oscillation or stirring.

In a third aspect, the invention provides a hydrogenation method of monomethyl quinoxaline compounds, which comprises the following steps:

the monomethyl quinoxaline compound and hydrogen are subjected to hydrogenation reaction under the action of a hydrogenation catalyst to obtain a fully hydrogenated compound.

Further, the hydrogenation catalyst comprises Ru/Al₂O₃、Pd/Al₂O₃、Pt/Al₂O₃、Rh/Al₂O₃Ru/C, Pd/C, Pt/C and Rh/C.

Further, the hydrogenation temperature is 150-200 ℃, and the hydrogenation pressure is 5-8 MPa;

further preferably, the hydrogenation temperature is 190 ℃ and the hydrogenation pressure is 7 MPa.

Further, the hydrogenation rotating speed is 300-800 r/min;

further preferably, the hydrogenation rotation speed is 500 r/min.

In a fourth aspect, the invention provides a dehydrogenation method of monomethyl quinoxaline compounds, which comprises the following steps:

the monomethyl quinoxaline compound and hydrogen are subjected to hydrogenation reaction under the action of a hydrogenation catalyst to obtain a fully hydrogenated compound;

and carrying out dehydrogenation reaction on the fully hydrogenated compound under the action of a dehydrogenation catalyst to obtain hydrogen.

Further, the dehydrogenation catalyst comprises Ru/Al₂O₃、Pd/Al₂O₃、Pt/Al₂O₃、Rh/Al₂O₃Ru/C, Pd/C, Pt/C and Rh/C.

Further, the dehydrogenation temperature is 150-200 ℃;

further preferably, the dehydrogenation rotating speed is 500-800 r/min.

Compared with the prior art, the invention has at least the following beneficial effects:

the monomethyl quinoxaline compound is applied to the hydrogen storage material, and can carry out liquid hydrogen storage at normal temperature and normal pressure without constructing a eutectic system, thereby reducing byproducts in the hydrogenation or dehydrogenation process and prolonging the service life of the hydrogen storage material; meanwhile, the monomethyl quinoxaline compound is applied to the hydrogen storage material, and has the advantages of low thermodynamic energy consumption, high-quality hydrogen storage density and low dehydrogenation temperature after hydrogenation, so that the utilization rate of energy is further improved.

The preparation method of the monomethyl quinoxaline compound provided by the invention is simple and convenient to operate and simple in process.

The hydrogenation method of the monomethyl quinoxaline compound provided by the invention has the characteristics of safety, high efficiency and convenience.

The dehydrogenation method of the monomethyl quinoxaline compound provided by the invention has the characteristics of safety, high efficiency and convenience.

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 reaction equation diagram of the hydrogenation of monomethyl quinoxalines according to one embodiment 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 a first aspect of the present invention, a monomethyl quinoxaline compound is used in a hydrogen storage material.

The monomethyl quinoxaline compound is applied to the hydrogen storage material, so that liquid hydrogen storage can be carried out at normal temperature and normal pressure, a eutectic system does not need to be constructed, byproducts in the hydrogenation or dehydrogenation process are reduced, the service life of the hydrogen storage material is prolonged, the advantages of low thermodynamic energy consumption, high quality hydrogen storage density and low dehydrogenation temperature after hydrogenation are achieved, and the utilization rate of energy is further improved.

In a preferred embodiment, the methyl position on the monomethylquinoxaline of the present invention may be any of 2-position, 5-position and 6-position, respectively, 2-methylquinoxaline, 5-methylquinoxaline and 6-methylquinoxaline, that is, at least one of the following compounds:

2-methylquinoxaline, 5-methylquinoxaline and 6-methylquinoxaline, the thermodynamic enthalpy of reversible hydrogenation being 6.4 to 6.7kWh/kg H₂The mass hydrogen storage density was 6.5 wt%. The 2-methylquinoxaline, the 5-methylquinoxaline and the 6-methylquinoxaline are liquid at normal temperature and normal pressure, so that a eutectic system is not required to be constructed, byproducts in the hydrogenation or dehydrogenation process are reduced, the service life is prolonged, and the method has the advantages of low energy consumption and high hydrogen storage density. Therefore, the 2-methylquinoxaline, the 5-methylquinoxaline and the 6-methylquinoxaline can be applied to the fields of rail transit, medium and long-distance commercial vehicles and the like, wherein the rail transit mainly comprises a high-speed train, a normal-speed motor train unit, a common train, a subway train, a light rail train, a monorail train and the like; the medium and long-distance commercial vehicles mainly comprise medium and heavy commercial vehicles and the like.

Meanwhile, the monomethyl quinoxaline compound can be single 2-methylquinoxaline, 5-methylquinoxaline and 6-methylquinoxaline, or a composition of any two or three of the 2-methylquinoxaline, the 5-methylquinoxaline and the 6-methylquinoxaline, the composition not only can ensure the mass hydrogen storage density of 6.5 wt%, but also can further reduce the melting point of the hydrogen storage material, enlarge the use environment range of the hydrogen storage material, can be used in a harsher environment, can not reduce the service life of the hydrogen storage material, has similar structures, and has consistent positions of groups subjected to catalytic hydrogenation and dehydrogenation, so that the hydrogen storage material and the fully hydrogenated hydrogen storage material are the most main materials in the hydrogenation and dehydrogenation reaction range, and other byproducts are few.

According to a second aspect of the present invention, a method for preparing monomethylquinoxalines, comprising the steps of:

weighing the single 2-methylquinoxaline, 5-methylquinoxaline or 6-methylquinoxaline, and mixing the single 2-methylquinoxaline, 5-methylquinoxaline or 6-methylquinoxaline in proportion to obtain a mixed monomethylquinoxaline compound; the mixing method includes, but is not limited to, ultrasonic oscillation or stirring.

The preparation method provided by the invention is convenient to operate, simple in process and high in efficiency.

According to a third aspect of the present invention, a hydrogenation method of monomethyl quinoxalines comprises the following steps:

the monomethyl quinoxaline compound and hydrogen are subjected to hydrogenation reaction under the action of a hydrogenation catalyst to obtain a fully hydrogenated compound.

In a preferred embodiment, the hydrogenation catalyst of the present invention comprises Ru/Al₂O₃、Pd/Al₂O₃、Pt/Al₂O₃、Rh/Al₂O₃Ru/C, Pd/C, Pt/C and Rh/C.

Note that, the catalyst of the present invention Ru/Al₂O₃、Pd/Al₂O₃、Pt/Al₂O₃、Rh/Al₂O₃Ru/C, Pd/C, Pt/C and Rh/C, Ru, Pd, Pt and Rh before "/" are catalysts, and Al after "/" is catalyst₂O₃And C as a carrier, e.g. Ru/Al₂O₃Expressed that the catalyst Ru is loaded on Al₂O₃The above.

In a preferred embodiment, the hydrogenation temperature of the present invention is 150 to 200 ℃, and typical but non-limiting temperatures are, for example, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, 200 ℃; the hydrogenation pressure is 5 to 8MPa, and typical but non-limiting pressures are, for example, 5MPa, 6MPa, 7MPa, and 8 MPa.

In a preferred embodiment, the hydrogenation is carried out at a rate of rotation of 300 to 800r/min, typical but not limiting rates being, for example, 300r/min, 400r/min, 500r/min, 600r/min, 700r/min, 800 r/min.

A typical hydrogenation method of monomethyl quinoxaline compound is shown as figure 1, and comprises the following steps:

1) the monomethyl quinoxaline compound comprises one or more of 2-methyl quinoxaline, 5-methyl quinoxaline and 6-methyl quinoxaline;

wherein, the mixed monomethyl quinoxaline compound can be in any proportion, and the preparation process comprises the following steps: respectively weighing single raw materials according to a ratio, pouring the single raw materials into a beaker, and performing ultrasonic vibration or stirring to obtain a mixed hydrogen storage material;

2) weighing the monomethyl quinoxaline compound and the catalyst according to the proportion, and placing the mixture in a reaction kettle for hydrogenation reaction; wherein the catalyst comprises Ru/Al₂O₃、Pd/Al₂O₃、Pt/Al₂O₃、Rh/Al₂O₃One or more of Ru/C, Pd/C, Pt/C and Rh/C; the hydrogenation reaction conditions are as follows: the heating temperature is 150-200 ℃, and 190 ℃ is preferred; the hydrogen pressure is 5-8 MPa, preferably 7 MPa; the rotating speed is 300-800 r/min, preferably 500 r/min;

3) and after the reaction is finished, reducing the temperature and releasing the pressure, separating the fully hydrogenated compound from the catalyst, and collecting the fully hydrogenated compound for later use.

The hydrogenation method provided by the invention is simple, convenient and efficient.

According to a fourth aspect of the present invention, a dehydrogenation method of monomethylquinoxalines, comprising the steps of:

carrying out hydrogenation reaction on the monomethyl quinoxaline compound and hydrogen under the action of a hydrogenation catalyst to obtain a fully hydrogenated compound;

the fully hydrogenated compound is subjected to dehydrogenation reaction under the action of a dehydrogenation catalyst to obtain hydrogen.

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

the catalyst Ru/Al₂O₃、Pd/Al₂O₃、Pt/Al₂O₃、Rh/Al₂O₃Ru/C, Pd/C, Pt/C and Rh/C, Ru, Pd, Pt and Rh before "/" are catalysts, and Al after "/" is catalyst₂O₃And C as a carrier, e.g. Ru/Al₂O₃Expressed that the catalyst Ru is loaded on Al₂O₃The above.

In a preferred embodiment, the dehydrogenation temperature of the present invention is 150 to 200 ℃, and typical but non-limiting temperatures are, for example, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, 200 ℃;

in a preferred embodiment, the dehydrogenation rate of the present invention is 500 to 800r/min, and typical but not limiting rotation rates thereof are, for example, 500r/min, 600r/min, 700r/min, 800 r/min.

A typical dehydrogenation method of monomethyl quinoxaline compounds comprises the following steps:

1) weighing the fully hydrogenated monomethyl quinoxaline compound and the dehydrogenation catalyst according to the weight ratio of 10: 1-5: 1, placing the mixture in a dehydrogenation reactor, wherein the dehydrogenation catalyst is Ru/Al₂O₃、Pd/Al₂O₃、Pt/Al₂O₃、Rh/Al₂O₃One or more of Ru/C, Pd/C, Pt/C and Rh/C;

2) and carrying out dehydrogenation reaction under the action of a dehydrogenation catalyst at the temperature of 150-200 ℃ and the rotating speed of 500-800 r/min to obtain hydrogen.

The invention is further illustrated by the following examples. The materials in the examples are prepared according to known methods or are directly commercially available, unless otherwise specified.

Examples 1 to 3

Examples 1 to 3 hydrogenation reactions were carried out using 2-methylquinoxaline, 5-methylquinoxaline and 6-methylquinoxaline, respectively, and the hydrogenation conditions, thermodynamic changes in the hydrogenation process and hydrogenation energy consumption are shown in Table 1.

The energy calculation method of the hydrogen storage system is as follows:

under the conditions of introducing hydrogen to pressurize and raise the temperature, LOHC + nH can be carried out₂＝LOHC*nH₂Carrying out reaction; wherein LOHC represents hydrogen storage material, LOHC nH₂Representing a perhydrogenated hydrogen storage material, the hydrogenation process involving the enthalpy of reaction (Δ H), the heating energy (Δ Q)_{T plus}) And boost energy (Δ Q)_p)。

Reaction enthalpy Δ H: the hydrogenation reaction outputs energy to the outside of the system. The calculation method is that the total energy of the resultant is subtracted by the total energy of the reactant to obtain reaction enthalpy delta H;

heating ofEnergy Δ Q_{T plus}: the energy required to heat the hydrogen and LOHC hydrogen storage materials from the initial temperature to the reaction temperature. The portion of energy is the energy input into the system. The calculation formula is as follows:

wherein, C_p1Is the constant pressure specific heat capacity of hydrogen, C_p2Is the constant pressure specific heat capacity of the LOHC material.

Supercharging energy DeltaQ_p: the compressed hydrogen energy required for maintaining the hydrogen pressure relates to the gas compression principle, and the temperature energy of the outlet gas is ignored because the staged compression is not carried out and the required maintained pressure is lower. The partial energy is the energy input into the system, the gas adiabatic index k of diatomic molecules is 1.4, η is the mechanical efficiency of the compressor, and η is 0.75.

Energy consumption: the heat exchange result of the hydrogenation reaction is the result of adding the three data. The calculation method is as follows:

Q_{energy source}＝ΔH+ΔQ_{T plus}+ΔQ_P

The hydrogenation catalysts used in examples 1-3 were all Ru/Al₂O₃。

TABLE 1 (energy units: kWh/kg H₂)

Material	Hydrogenation conditions	ΔH	ΔQT plus	ΔQp	Energy consumption
						2-methylquinoxaline	190℃、7MPa	-6.4	+1.52	+3.54	-1.34
5-methylquinoxaline	190℃、7MPa	-6.6	+1.47	+3.54	-1.59
						6-methylquinoxaline	190℃、7MPa	-6.7	+1.48	+3.54	-1.68

The energy loss is measured by 33.3kWh energy of 1kg hydrogen, and "+" represents energy required to be supplied to the system from the outside, and "-" represents energy released to the outside from the system.

Examples 4 to 6

Examples 4 to 6 were performed with dehydrogenation reaction of 10H-2-methylquinoxaline, 10H-5-methylquinoxaline and 10H-6-methylquinoxaline, respectively, and the dehydrogenation conditions, dehydrogenation energy consumption and dehydrogenation energy loss are shown in Table 2.

The dehydrogenation process is under normal pressure, and the fully hydrogenated hydrogen storage material needs to absorb energy from the outside to generate dehydrogenation reaction. The partial energy comprises two parts, one partThe reaction enthalpy is divided into reversible reaction enthalpy delta H and energy delta Q required by the process of heating from the initial temperature to the reaction temperature_{T-shaped stripper}。

Reversible reaction enthalpy Δ H: the value of delta H is the same as that of hydrogenation reaction, hydrogenation and dehydrogenation are reversible reactions and are obtained by calculation in the hydrogenation reaction, and the dehydrogenation reaction can be directly used.

ΔQ_{T-shaped stripper}: the energy required for the perhydrogenated LOHC material to heat up from the initial temperature to the reaction temperature. The portion of energy is the energy input into the system. The calculation formula is as follows:

C_p3is the constant pressure specific heat capacity of the perhydrogenated LOHC material.

Energy consumption: heat exchange results of the dehydrogenation reaction.

Q_{Energy source}＝ΔH+ΔQ_{T-shaped stripper}

The dehydrogenation catalysts used in examples 4-6 were Pd/C.

TABLE 2 (energy units: kWh/kg H₂)

Material	Dehydrogenation conditions	Energy consumption (Δ H + Δ Q)T-shaped stripper)	Ratio of energy loss
				10H-2-methylquinoxaline	150～200℃	7.36～7.9	22.1～23.7％
10H-5-methylquinoxaline	150～200℃	7.56～8.1	22.7％～24.3％
				10H-6-methylquinoxaline	150～200℃	7.66～8.2	23.0％～24.6％

Examples 7 to 10

Example 7 with a molar ratio of 3: 1, taking 2-methylquinoxaline and 5-methylquinoxaline, placing the 2-methylquinoxaline and the 5-methylquinoxaline in a beaker, and then fully mixing the 2-methylquinoxaline and the 5-methylquinoxaline by ultrasonic oscillation to obtain a hydrogen storage mixed material A; the hydrogenation reaction of the hydrogen storage mixed material A is carried out, and the hydrogenation conditions, the thermodynamic change of the hydrogenation process and the hydrogenation energy consumption are shown in Table 3.

Example 8 in a molar ratio of 2: 1, taking 2-methylquinoxaline and 6-methylquinoxaline, placing the 2-methylquinoxaline and the 6-methylquinoxaline in a beaker, and then fully mixing the 2-methylquinoxaline and the 6-methylquinoxaline by ultrasonic oscillation to obtain a hydrogen storage mixed material B; the hydrogen storage mixed material B is subjected to hydrogenation reaction, and the hydrogenation conditions, the thermodynamic change of the hydrogenation process and the hydrogenation energy consumption are shown in Table 3.

Example 9 with a molar ratio of 5: 1, taking 5-methylquinoxaline and 6-methylquinoxaline, placing the 5-methylquinoxaline and the 6-methylquinoxaline in a beaker, and then fully mixing the 5-methylquinoxaline and the 6-methylquinoxaline by ultrasonic oscillation to obtain a hydrogen storage mixed material C; the hydrogenation reaction of the hydrogen storage mixed material C is carried out, and the hydrogenation conditions, the thermodynamic change of the hydrogenation process and the hydrogenation energy consumption are shown in Table 3.

Example 10 with a molar ratio of 3: 1: 1, taking 2-methylquinoxaline, 5-methylquinoxaline and 6-methylquinoxaline, placing the 2-methylquinoxaline, the 5-methylquinoxaline and the 6-methylquinoxaline in a beaker, and then fully mixing the 2-methylquinoxaline, the 5-methylquinoxaline and the 6-methylquinoxaline by ultrasonic oscillation to obtain a hydrogen storage mixed material D; the hydrogenation reaction of the hydrogen storage mixed material D is carried out, and the hydrogenation conditions, the thermodynamic change of the hydrogenation process and the hydrogenation energy consumption are shown in Table 3.

The hydrogenation catalysts used in examples 7-10 were all Ru/Al₂O₃。

TABLE 3 (energy units: kWh/kg H₂)

The energy loss is measured by 33.3kWh energy of 1kg hydrogen, and "+" represents energy required to be supplied to the system from the outside, and "-" represents energy released to the outside from the system.

Examples 11 to 14

In examples 11 to 14, dehydrogenation reactions were carried out on the hydrogen storage mixture material a after full hydrogenation, the hydrogen storage mixture material B after full hydrogenation, the hydrogen storage mixture material C after full hydrogenation, and the hydrogen storage mixture material D after full hydrogenation, respectively, and the dehydrogenation conditions, dehydrogenation energy consumption, and dehydrogenation energy loss ratios are shown in table 4.

The dehydrogenation catalysts used in examples 11-14 were all Pd/C.

TABLE 4 (energy units: kWh/kg H₂)

Comparative example 1

The dehydrogenation energy loss based on perhydrodibenzyltoluene from the German HT company is 37.4%.

Comparative example 2

The methylcyclohexane-based dehydrogenation energy loss of the thousand dairies in japan was 35%.

Analysis of

As can be seen from tables 1 and 2, the hydrogenation of 2-methyl quinoxaline, 5-methyl quinoxaline and 6-methyl quinoxaline of the present invention has low thermodynamic energy consumption, and the dehydrogenation energy consumption after hydrogenation is about 7.36 to 8.2kWh/kg H₂The lowest energy loss ratio is 22.1 percent; from Table 1 andas can be seen in Table 2, the hydrogen storage material of the present invention, which releases energy to the outside during hydrogenation, is an exothermic reaction and does not take into account energy loss; meanwhile, the dehydrogenation reaction after perhydrogenation, even at 200 ℃, has an energy loss lower than 25%, much lower than that of the German HT company based on perhydro dibenzyl toluene (37.4%), and lower than that of the Japan Kyoho based on methylcyclohexane (35%).

In addition, the mass hydrogen storage density of the hydrogen storage material of the invention, namely the monomethyl quinoxaline, is 6.5wt percent, which is superior to the hydrogen storage density of dibenzyltoluene (6.2wt percent), toluene (6.1wt percent) and carbazoles (less than 5.75wt percent).

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.