阅读说明：本技术 一种金属配合物储氢材料及其制备方法 (Metal complex hydrogen storage material and preparation method thereof ) 是由 郑欣 李宗红 邱方程 李寒煜 刘荣海 杨雪滢 于 2021-07-16 设计创作，主要内容包括：本发明公开了一种金属配合物储氢材料及其制备方法,制备步骤简捷,是一种具备自催化功能的有机储氢材料,通过金属配位化合物的方法,能够有效的实现有机分子的自催化吸放氢,从而改善有机化合物储氢材料的吸放氢性能,无需添加其他催化剂,能够简化加氢装置要求,提高化学储氢材料的适用性。(The invention discloses a metal complex hydrogen storage material and a preparation method thereof, the preparation steps are simple, the metal complex hydrogen storage material is an organic hydrogen storage material with an autocatalysis function, and the autocatalysis hydrogen absorption and desorption of organic molecules can be effectively realized by a method of a metal coordination compound, so that the hydrogen absorption and desorption performance of the organic compound hydrogen storage material is improved, other catalysts are not required to be added, the requirement of a hydrogenation device can be simplified, and the applicability of a chemical hydrogen storage material is improved.)

1. A metal complex hydrogen storage material characterized by: the metal ion complex is a complex generated by the reaction of metal ions and a nitrogen heterocyclic compound ligand, wherein the nitrogen heterocyclic compound ligand is a derivative of quinoline, a derivative of acridine or a derivative of phenanthridine, and the nitrogen heterocyclic compound contains at least one pyridine group and does not contain an oxygen-containing group.

2. A metal complex hydrogen storage material according to claim 1, wherein: the metal ions are nickel ions, and the nickel ions are from nickel nitrate or nickel chloride.

3. A preparation method of a metal complex hydrogen storage material is characterized by comprising the following steps: dissolving a mixture of a proper amount of nitrogen heterocyclic compound ligand and nickel salt in a DMF solution to obtain a mixed solution, wherein the concentration of nickel ions in the mixed solution is 0.1mol/L, and the concentration of the nitrogen heterocyclic compound ligand is 0.5-2 times of the concentration of the nickel ions, then heating the mixed solution for 72 hours at the temperature of 120 ℃ and 150 ℃, and then cleaning and filtering to obtain a green solid.

4. The method of claim 3, wherein the metal complex hydrogen storage material comprises: adding a proper amount of nitric acid into the mixed solution, and heating for 72 hours.

5. The method of claim 3, wherein the metal complex hydrogen storage material comprises: the nitrogen heterocyclic compound ligand is a quinoline derivative, an acridine derivative or a phenanthridine derivative, and the nitrogen heterocyclic compound contains at least one pyridine group.

6. The method of claim 3, wherein the metal complex hydrogen storage material comprises: the nickel salt is nickel nitrate or nickel chloride.

Technical Field

The invention belongs to the technical field of chemical hydrogen storage, and particularly relates to a metal complex hydrogen storage material and a preparation method thereof.

Background

In the technical field of hydrogen storage, the chemical hydrogen storage technology has the characteristics of stable hydrogen storage and high safety and is widely applied, but the ethyl carbazole which is taken as a representative heterocyclic chemical hydrogen storage material can realize hydrogenation under the action of a noble metal solid catalyst, so that a device for carrying out hydrogenation reaction is complex, the cost is high, and the operation is complex. Therefore, a chemical hydrogen storage material with an autocatalysis effect is developed, the requirements of a hydrogenation device can be simplified, and the applicability of the chemical hydrogen storage material is improved.

Disclosure of Invention

The invention aims to overcome the defect that the prior heterocyclic chemical hydrogen storage material can realize hydrogenation only by adding a noble metal solid catalyst, so that the equipment is complex, and provides a metal complex hydrogen storage material and a preparation method thereof.

The invention adopts the following technical scheme:

the key point of the metal complex hydrogen storage material is as follows: the metal ion complex is a complex generated by the reaction of metal ions and a nitrogen heterocyclic compound ligand, wherein the nitrogen heterocyclic compound ligand is a derivative of quinoline, a derivative of acridine or a derivative of phenanthridine, and the nitrogen heterocyclic compound contains at least one pyridine group and does not contain an oxygen-containing group.

Preferably, the metal ions are nickel ions, and the nickel ions are derived from nickel nitrate or nickel chloride.

The preparation method of the metal complex hydrogen storage material is characterized in that: dissolving a mixture of a proper amount of nitrogen heterocyclic compound ligand and nickel salt in a DMF solution to obtain a mixed solution, wherein the concentration of nickel ions in the mixed solution is 0.1mol/L, and the concentration of the nitrogen heterocyclic compound ligand is 0.5-2 times of the concentration of the nickel ions, then heating the mixed solution for 72 hours at the temperature of 120 ℃ and 150 ℃, and then cleaning and filtering to obtain a green solid.

Preferably, the mixed solution is heated for 72 hours after adding a proper amount of nitric acid.

Preferably, the nitrogen heterocyclic compound ligand is a quinoline derivative, an acridine derivative or a phenanthridine derivative.

Preferably, the nickel salt is nickel nitrate or nickel chloride.

Has the advantages that: the metal complex hydrogen storage material and the preparation method thereof have simple and convenient preparation steps, are organic hydrogen storage materials with self-catalysis function, and can effectively realize self-catalysis hydrogen absorption and desorption of organic molecules by a method of metal coordination compounds, thereby improving the hydrogen absorption and desorption performance of the organic compound hydrogen storage material, needing no addition of other catalysts, simplifying the requirements of hydrogenation devices and improving the applicability of chemical hydrogen storage materials.

Drawings

FIG. 1 is an X-ray diffraction pattern of the synthetic starting material and the product of example 1;

FIG. 2 is a graph comparing the kinetics of hydrogen absorption of 6- (pyridin-4-yl) isoquinoline with 50% metallic Ni catalysis for the synthesized product of example 1;

FIG. 3 is a graph comparing the hydrogen evolution kinetics of the product of the synthesis of example 1 with 6- (pyridin-4-yl) isoquinoline catalyzed by 50% metallic Ni;

FIG. 4 is a graph showing the X-ray diffraction pattern of the synthesized product of example 1 after hydrogen absorption;

FIG. 5 is an XRD test pattern of the synthesized product of example 2;

FIG. 6 is a graph showing the hydrogen absorption kinetics of the synthesized product of example 2;

FIG. 7 is a graph showing the hydrogen evolution kinetics of the synthesized product of example 2.

Detailed Description

The invention is described in further detail below with reference to the following figures and examples:

a metal complex hydrogen storage material is a complex generated by the reaction of metal ions and a nitrogen heterocyclic compound ligand, wherein the nitrogen heterocyclic compound ligand is a derivative of quinoline, a derivative of acridine or a derivative of phenanthridine, and the nitrogen heterocyclic compound contains at least one pyridine group and does not contain an oxygen-containing group. Wherein the metal ions are nickel ions, and the nickel ions are from nickel nitrate or nickel chloride.

A method for preparing a metal complex hydrogen storage material comprises the steps of dissolving a mixture of a proper amount of nitrogen heterocyclic compound ligand and nickel salt in a DMF solution to obtain a mixed solution, wherein the concentration of nickel ions in the mixed solution is 0.1mol/L, and the concentration of the nitrogen heterocyclic compound ligand is 0.5-2 times of the concentration of the nickel ions, heating the mixed solution at the temperature of 120-150 ℃, cleaning and filtering to obtain a green solid.

Adding a proper amount of nitric acid into the mixed solution, and heating for 72 hours. The nitrogen heterocyclic compound ligand is a quinoline derivative, an acridine derivative or a phenanthridine derivative. The nickel salt is nickel nitrate or nickel chloride.

Example 1:

using analytically pure Ni (NO)₃)₂·6H₂O is used as a Ni ion donor, 6- (pyridine-4-yl) isoquinoline (PIQ, 95%) is used as a nitrogen heterocyclic compound ligand, and a metal complex is synthesized by a solvothermal method. Dissolving the raw material in 40ml of N-Dimethylformamide (DMF) solvent, controlling Ni²⁺The ion concentration is 1mol/L, and the ligand concentration is 2 mol/L. The solution was placed in a stainless steel reaction vessel with a 50ml volume and sealed with a polytetrafluoroethylene liner, and heated at 120 ℃ for reaction for 72 hours. And the reaction product is solid powder insoluble in DMF, and is subjected to suction filtration separation, then methanol and deionized water are adopted for rinsing and filtration for 2 times respectively, and finally the filtration product is dried in an air-blast drying oven at 100 ℃ for 4 hours to obtain a synthetic product.

Comparative experiment: metallic nickel catalyst made of Ni (NO)₃)₂·6H₂Calcining O at 873K for 4 hours, and heating to 523K under a hydrogen atmosphere of 5MPa to reduce to obtain the catalyst. Metal Ni catalyst with 6- (pyridin-4-yl) isoquinoline according to 1: 1 mass ratio in a mortar, and then, the mixture was used for the hydrogen absorption and desorption test.

The phase change of the synthetic product and before and after hydrogen absorption and desorption is characterized by adopting a Japan science MiniFlex 600X-ray diffractometer, and a Cu-K alpha radiation source with the voltage of 40kV is adopted. Hydrogen absorption and desorption kinetics tests are carried out by adopting a PCT-2000Pro type gas adsorption instrument of Setaram company, the testing temperature is 483K, the initial hydrogen absorption pressure is 5.5MPa, the initial hydrogen desorption pressure is 0.02MPa, the testing dosage of a synthetic product is 0.1g, and the testing dosage of a 50 percent Ni/6- (pyridine-4-yl) isoquinoline mixture is 0.2 g. The results are as follows:

1) characterization of the synthesized product: miningXRD on Ni (NO)₃)2·6H₂The characterization of O, 6- (pyridine-4-yl) isoquinoline and the synthesized product shows that the diffraction pattern is shown in figure 1, and the product with a brand new crystal structure is generated in the synthesis process. Tests show that the synthesized product is insoluble in DMF, ethyl acetate, acetonitrile and other common solvents, and the product cannot be purified and crystallized, so that the specific crystal structure of the synthesized product cannot be calibrated by single crystal diffraction analysis.

2) Testing the hydrogen absorption and desorption performance of the synthesized product:

as shown in attached figures 2 and 3, a hydrogen absorption and desorption test is carried out on the synthetic product under the condition of 483K, the hydrogen absorption and desorption performance of 6- (pyridine-4-yl) isoquinoline under the catalysis of 50 percent of metal Ni is tested as a comparison, the hydrogen absorption kinetic curve is shown in figure 2, and the hydrogen absorption pressure is 5.5 MPa; the hydrogen evolution kinetics are shown in FIG. 3, with an initial hydrogen evolution pressure of 0.02 MPa. The synthesized product showed a maximum hydrogen absorption of 0.93 wt%, and a hydrogen release of 0.33 wt% was achieved within 2 hours; the 6- (pyridine-4-yl) isoquinoline catalyzed by 50 percent of metal Ni achieves the maximum hydrogen absorption of 1.4 weight percent, and the hydrogen release reaches 0.38 weight percent after 2 hours. Compared with the hydrogen absorption kinetics of the ligand catalyzed by Ni, the hydrogen absorption kinetics speed of the synthesized product is obviously improved, the saturated hydrogen absorption time is reduced to about 0.3 hour from 4 hours, but the saturated hydrogen absorption amount is reduced; both have similar hydrogen evolution kinetic rates, but the hydrogen evolution of the synthesized product is reduced.

3) Characterization of the synthesized product after hydrogen sorption:

as shown in figure 4, XRD is used for phase analysis of the product after hydrogen absorption, diffraction pattern is shown in figure 4, diffraction data shows that significant metal Ni crystal structure exists, steamed bread-shaped diffraction peak and part of unknown diffraction peak formed by amorphous substance exist in 2-40 degree interval, and ligand material Ni (NO) is obtained₃)₂· 6H₂Comparison of O, 6- (pyridin-4-yl) isoquinoline shows that these unknown diffraction peaks do not originate from the starting materials of synthesis. Diffraction analysis results show that the synthesized product is decomposed during hydrogenation to generate metal Ni.

From the analysis results of example 1 and its comparative test, it can be seen that: ni is synthesized by solvothermal reaction²⁺6- (pyridin-4-yl) isoquinoline ComplexThe formation of the complex was confirmed by X-ray diffraction analysis of the compound. . The hydrogen absorption and desorption tests show that the coordination compound can realize autocatalytic hydrogen absorption and desorption, the hydrogen absorption and desorption amount respectively reaches 0.93 wt% and 0.33 wt%, and compared with 6- (pyridine-4-yl) isoquinoline catalyzed by 50% of metal Ni, the maximum hydrogen absorption amount is reduced (0.93 wt% to 1.4 wt%), but the hydrogen absorption kinetics is greatly improved, and the synthetic product can reach saturated hydrogen absorption within about 0.3 hour; the hydrogen release kinetic speed of the synthesized product is close to that of a ligand catalyzed by Ni, the maximum hydrogen release amount is 0.33 wt%, and the maximum hydrogen release amount of the ligand under the catalysis of Ni is 0.35%. The hydrogen absorption and desorption mechanism of the catalyst is the catalytic effect generated by the reduction of metallic nickel. Metallic Ni in coordinated state²⁺The ions have better dispersibility and smaller particles after reduction, thus having better catalytic effect in the process of absorbing and releasing hydrogen, and explaining the reason that the synthesized product has better hydrogen absorption dynamic performance. Research shows that the self-catalysis hydrogen absorption and desorption of organic molecules can be effectively realized by a method of metal coordination compounds, so that the hydrogen absorption and desorption performance of the organic compound hydrogen storage material is improved.

Example 2: the nitrogen heterocyclic compound ligand adopts 5, 8-di (4-carboxyl benzene) quinoline (DPC) (10mg, 0.03mmol) and Ni (NO)₃)₂·6H₂A mixture of O (18mg, 0.06mmol) was dissolved in a mixed solvent of 2mL of DMF and 2mL of water, 100. mu.L of nitric acid was added, and the mixture was placed in a 25mL stainless steel reaction vessel lined with polytetrafluoroethylene and reacted at 150 ℃ for 72 hours to obtain green needle-like crystals. XRD test of the synthesized product of example 2 showed that the green needle-like crystals were not any of the starting materials as shown in FIG. 5; the results of the hydrogen absorption and desorption tests are shown in fig. 6 and fig. 7, the hydrogen absorption and desorption area line is similar to the curve ratio of the synthetic product of the example 1, and the synthetic product of the example 2 has good hydrogen absorption and desorption performance.

Finally, it should be noted that the above-mentioned description is only a preferred embodiment of the present invention, and those skilled in the art can make various similar representations without departing from the spirit and scope of the present invention.