Reversible hydrogen storage material and method for producing the same

Abstract

This invention provides a reversible hydrogen storage material and its preparation method, relating to the field of hydrogen energy storage technology. The reversible hydrogen storage material provided by this invention comprises, by weight percentage: 20-30% hydrogen storage catalyst, 10-15% support, and the balance rare earth oxides; the hydrogen storage catalyst includes at least one of cobalt-based and zinc-based catalysts. The preparation method provided by this invention includes the following steps: grinding and sieving the hydrogen storage catalyst and rare earth oxides, then adding them to an alkaline aqueous solution of sodium borohydride, stirring and reacting, filtering, washing, and drying to obtain a hydrogen storage precursor material; adding the hydrogen storage precursor material and support to a dispersion, heating to the boiling point of the dispersion, maintaining the temperature at boiling for 2-3 hours, filtering, and drying to obtain the hydrogen storage material. This invention can increase the mass fraction of hydrogen in the hydrogen storage material after hydrogen storage, while simultaneously improving its reversibility.

Description

Technical Field

[0001] This invention relates to the field of hydrogen energy storage technology, and in particular to a reversible hydrogen storage material and its preparation method. Background Technology

[0002] With the increasing depletion of petrochemical resources and the environmental pollution they cause, developing non-polluting renewable energy sources has become an urgent task facing humanity, and hydrogen energy is considered the most promising clean energy source of the 21st century. However, the lack of convenient and effective hydrogen storage materials and technologies has long hindered the application of hydrogen energy.

[0003] Current research on hydrogen storage materials mainly includes hydrogen storage alloys, coordination hydrides, amino compounds, organic liquids, carbon-based materials, and metal-organic frameworks. Among these, the more mature hydrogen storage alloy materials mainly fall into four major series: rare earth-based AB5 type, AB2 type, magnesium-based, and Fe-Ti series. The rare earth-based AB5 type hydrogen storage alloy LaNi5 is the earliest commercially available hydrogen storage alloy. Its advantages include easy activation, moderate hydrogen decomposition pressure, small hydrogen absorption / desorption equilibrium pressure difference, excellent kinetic performance, and low susceptibility to poisoning. However, its disadvantages include lattice expansion after hydrogen absorption, easy alloy pulverization, and a relatively low hydrogen mass fraction after storage due to lanthanum being a heavy element. Therefore, there is an urgent need to provide a solution to improve this problem. Summary of the Invention

[0004] The purpose of this invention is to provide a reversible hydrogen storage material and its preparation method, which can increase the mass fraction of hydrogen in the hydrogen storage material after hydrogen storage, and at the same time improve its reversibility of hydrogen storage.

[0005] In a first aspect, the present invention provides a reversible hydrogen storage material comprising, by weight percentage: 20-30% hydrogen storage catalyst, 10-15% support material and balance rare earth oxides; wherein the hydrogen storage catalyst comprises at least one of cobalt-based catalyst and zinc-based catalyst.

[0006] Optionally, when the hydrogen storage catalyst includes a cobalt-based catalyst, the preparation method of the cobalt-based catalyst includes the following steps: dissolving cobalt salt and calcium salt in a polyethylene glycol-water mixture and then evaporating the solvent to obtain a precursor, and calcining the precursor under a nitrogen atmosphere at 500-700°C to obtain the cobalt-based catalyst.

[0007] Optionally, after dissolving the cobalt salt and calcium salt in a polyethylene glycol aqueous solution, the molar ratio of cobalt ions to calcium ions in the mixed solution is 1:(0.2-0.3).

[0008] Optionally, when the hydrogen storage catalyst includes a zinc-based catalyst, the preparation method of the zinc-based catalyst includes the following steps: calcining zinc nitrate hydrate at 300-400°C to obtain a zinc precursor; adding the zinc precursor to a solution containing dissolved nickel salt, stirring and impregnating, and filtering to obtain a zinc intermediate; drying the zinc intermediate in an environment of 100-200°C and grinding to obtain a zinc catalyst.

[0009] Optionally, when the zinc precursor is added to a solution containing a nickel salt, the mass ratio of the zinc precursor to the nickel salt is 1:(5-8).

[0010] Optionally, when the hydrogen storage catalyst comprises a cobalt-based catalyst and a zinc-based catalyst, the mass ratio of the cobalt-based catalyst to the zinc-based catalyst is 1:(1-2).

[0011] Optionally, the rare earth oxide includes at least one of CeO2, Y2O3, Nd2O3, Gd2O3 and La2O3.

[0012] Optionally, the carrier material includes at least one of silicon dioxide and aluminum oxide.

[0013] Secondly, the present invention also provides a method for preparing a reversible hydrogen storage material, comprising the following steps: grinding and sieving a hydrogen storage catalyst and a rare earth oxide, then adding them to an alkaline aqueous solution of sodium borohydride, stirring and reacting, filtering, washing and drying to obtain a hydrogen storage precursor material; adding the hydrogen storage precursor material and a carrier to a dispersion, heating to the boiling point of the dispersion, keeping it at the boiling point for 2-3 hours, filtering and drying to obtain the hydrogen storage material.

[0014] Optionally, the dispersion comprises deionized water. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0016] The present invention provides a reversible hydrogen storage material comprising, by weight percentage: 20-30% hydrogen storage catalyst, 10-15% support and balance rare earth oxides; wherein the hydrogen storage catalyst comprises at least one of cobalt-based catalyst and zinc-based catalyst.

[0017] In some embodiments, when the hydrogen storage catalyst includes a cobalt-based catalyst, the preparation method of the cobalt-based catalyst includes the following steps: dissolving cobalt salt and calcium salt in a polyethylene glycol-water mixture and then evaporating the solvent to obtain a precursor, and calcining the precursor under a nitrogen atmosphere at 500-700°C to obtain the cobalt-based catalyst.

[0018] In fact, after dissolving cobalt salt and calcium salt in a polyethylene glycol aqueous solution, the molar ratio of cobalt ions to calcium ions in the mixed solution is 1:(0.2-0.3).

[0019] In some embodiments, when the hydrogen storage catalyst includes a zinc-based catalyst, the preparation method of the zinc-based catalyst includes the following steps: calcining zinc nitrate hydrate at 300-400°C to obtain a zinc precursor; adding the zinc precursor to a solution containing dissolved nickel salt, stirring and impregnating, and filtering to obtain a zinc intermediate; and drying the zinc intermediate in an environment of 100-200°C and grinding to obtain a zinc catalyst.

[0020] In practice, when the zinc precursor is added to a solution containing dissolved nickel salt, the mass ratio of the zinc precursor to the nickel salt is 1:(5-8).

[0021] In some embodiments, when the hydrogen storage catalyst comprises a cobalt-based catalyst and a zinc-based catalyst, the mass ratio of the cobalt-based catalyst to the zinc-based catalyst is 1:(1-2).

[0022] In some embodiments, the rare earth oxide includes at least one of CeO2, Y2O3, Nd2O3, Gd2O3, and La2O3.

[0023] In some embodiments, the carrier material includes at least one of silicon dioxide and aluminum oxide.

[0024] The present invention also provides a method for preparing reversible hydrogen storage materials in any of the above embodiments, comprising the following steps: grinding and sieving a hydrogen storage catalyst and a rare earth oxide, then adding the catalyst to an alkaline aqueous solution of sodium borohydride, stirring and reacting, filtering, washing and drying to obtain a hydrogen storage precursor material; adding the hydrogen storage precursor material and a carrier to a dispersion, heating to the boiling point of the dispersion, keeping it at the boiling point for 2-3 hours, filtering and drying to obtain a hydrogen storage material.

[0025] In fact, the dispersion includes deionized water.

[0026] Preparation Example 1

[0027] Example 1 provides a method for preparing a cobalt-based catalyst, comprising the following steps:

[0028] Y1. A cobalt-calcium mixed solution is prepared by adding 10 mol of cobalt nitrate and 2 mol of calcium chloride into a mixture of polyethylene glycol and water at a volume ratio of 1:1 and stirring the solution.

[0029] Y2. A cobalt-calcium precursor was prepared by evaporating the solvent in a cobalt-calcium mixed solution under an argon atmosphere. The cobalt-calcium precursor was then calcined in a muffle furnace under a nitrogen atmosphere at 600°C and ground through a 200-mesh sieve to obtain a cobalt-based catalyst.

[0030] Preparation Example 2

[0031] Example 2 provides a method for preparing a zinc-based catalyst, comprising the following steps:

[0032] D1. Zinc nitrate hydrate was placed in a muffle furnace and calcined at 350°C in an inert atmosphere until its mass no longer changed, and then cooled to room temperature to obtain the zinc precursor.

[0033] D2. Add 100g of zinc precursor to an aqueous solution containing 600g of nickel nitrate, stir and impregnate, then filter to obtain zinc intermediate.

[0034] D3. The zinc intermediate was dried in a vacuum drying oven at 150°C until its mass no longer changed, and then ground through a 200-mesh sieve to obtain a zinc-based catalyst.

[0035] Example 1

[0036] This Example 1 provides a method for preparing a reversible hydrogen storage material based on Preparation Example 1, including the following steps:

[0037] S1. 20g of cobalt-based catalyst and 65g of cerium oxide are put into a grinding device, ground and mixed, and then passed through a 50-mesh sieve to obtain a mixed powder.

[0038] S2. The mixed powder was added to an alkaline aqueous solution of sodium borohydride and ultrasonically dispersed. The mixture was then ultrasonically reacted at room temperature of 25°C. After the reaction was completed, the mixture was filtered and washed with deionized water and ethanol in a cycle. After drying, the hydrogen storage precursor material was obtained.

[0039] S3. The hydrogen storage precursor material is mixed with 15g of silica powder, ground and passed through a 100-mesh sieve, and then placed in deionized water for ultrasonic dispersion to obtain a precursor dispersion. The precursor dispersion is heated to 100℃ and kept at that temperature for 2 hours, then filtered and dried to obtain a reversible hydrogen storage material.

[0040] Example 2

[0041] This Example 2 provides a method for preparing a reversible hydrogen storage material based on Preparation Example 2, including the following steps:

[0042] S1. 20g of zinc-based catalyst and 65g of cerium oxide are put into a grinding device, ground and mixed, and then passed through a 50-mesh sieve to obtain a mixed powder.

[0043] S2. The mixed powder was added to an alkaline aqueous solution of sodium borohydride and ultrasonically dispersed. The mixture was then ultrasonically reacted at room temperature of 25°C. After the reaction was completed, the mixture was filtered and washed with deionized water and ethanol in a cycle. After drying, the hydrogen storage precursor material was obtained.

[0044] S3. The hydrogen storage precursor material is mixed with 15g of silica powder, ground and passed through a 100-mesh sieve, and then placed in deionized water for ultrasonic dispersion to obtain a precursor dispersion. The precursor dispersion is heated to 100℃ and kept at that temperature for 2 hours, then filtered and dried to obtain a reversible hydrogen storage material.

[0045] Example 3

[0046] This Example 3 provides a method for preparing a reversible hydrogen storage material based on Preparation Example 1 and Preparation Example 2, including the following steps:

[0047] S1. Add 10g of zinc-based catalyst, 10g of cobalt-based catalyst and 65g of cerium oxide into a grinding equipment, grind and mix them, and then pass them through a 50-mesh sieve to obtain a mixed powder.

[0048] S2. The mixed powder was added to an alkaline aqueous solution of sodium borohydride and ultrasonically dispersed. The mixture was then ultrasonically reacted at room temperature of 25°C. After the reaction was completed, the mixture was filtered and washed with deionized water and ethanol in a cycle. After drying, the hydrogen storage precursor material was obtained.

[0049] S3. The hydrogen storage precursor material is mixed with 15g of silica powder, ground and passed through a 100-mesh sieve, and then placed in deionized water for ultrasonic dispersion to obtain a precursor dispersion. The precursor dispersion is heated to 100℃ and kept at that temperature for 2 hours, then filtered and dried to obtain a reversible hydrogen storage material.

[0050] Comparative Example 1

[0051] Comparative Example 1 provides a method for preparing a reversible hydrogen storage material, including the following steps:

[0052] S1. 85g of cerium oxide was added to an alkaline aqueous solution of sodium borohydride and ultrasonically dispersed. The reaction was carried out at room temperature of 25°C. After the reaction was completed, the mixture was filtered and washed with deionized water and ethanol in a cycle. After drying, the hydrogen storage precursor material was obtained.

[0053] S2. The hydrogen storage precursor material is mixed with 15g of silica powder, ground and passed through a 100-mesh sieve, and then placed in deionized water for ultrasonic dispersion to obtain a precursor dispersion. The precursor dispersion is heated to 100℃ and kept at that temperature for 2 hours, then filtered and dried to obtain a reversible hydrogen storage material.

[0054] Performance testing

[0055] The reversible hydrogen storage materials prepared in Examples 1 to 3 and Comparative Example 1 were subjected to a first reversible hydrogen release test at a hydrogen absorption pressure of 3 MPa, a hydrogen absorption temperature of 10-30℃, and a hydrogen release temperature of 150℃. The test results are shown in Table 1 below.

[0056] Table 1 First Reversible Hydrogen Emission Test

[0057]

[0058] As can be seen from Table 1, the reversible hydrogen storage material provided by the present invention has good hydrogen storage performance, a high hydrogen storage capacity, and can release the stored hydrogen in a short time, and has good reversibility.

[0059] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A method for preparing a reversible hydrogen storage material, characterized in that... Includes the following steps: The hydrogen storage catalyst and rare earth oxide were ground and sieved, then added to an alkaline aqueous solution of sodium borohydride, stirred and reacted, filtered, washed and dried to obtain a hydrogen storage precursor material; the hydrogen storage precursor material and the carrier were added to a dispersion and heated to the boiling point of the dispersion, kept at the temperature and boiled for 2-3 hours, then filtered and dried to obtain a hydrogen storage material. The hydrogen storage catalyst comprises a cobalt-based catalyst and a zinc-based catalyst in a mass ratio of 1:(1-2); The preparation method of the cobalt-based catalyst includes the following steps: dissolving cobalt salt and calcium salt in a polyethylene glycol-water mixture and then evaporating the solvent to obtain a precursor; calcining the precursor under a nitrogen atmosphere at 500-700℃ to obtain the cobalt-based catalyst. The preparation method of the zinc-based catalyst includes the following steps: calcining zinc nitrate hydrate at 300-400℃ to obtain a zinc precursor; adding the zinc precursor to a solution containing nickel salt, stirring and impregnating, and filtering to obtain a zinc intermediate; drying the zinc intermediate in an environment of 100-200℃ and grinding to obtain a zinc catalyst.

2. The preparation method according to claim 1, characterized in that, The dispersion comprises deionized water.

3. The preparation method according to claim 1, characterized in that, After dissolving cobalt and calcium salts in an aqueous polyethylene glycol solution, the molar ratio of cobalt ions to calcium ions in the mixed solution is 1:(0.2-0.3).

4. The preparation method according to claim 1, characterized in that, When the zinc precursor is added to a solution containing nickel salt, the mass ratio of the zinc precursor to the nickel salt is 1:(5-8).

5. The preparation method according to claim 1, characterized in that, The rare earth oxides include at least one of CeO2, Y2O3, Nd2O3, Gd2O3, and La2O3.

6. The preparation method according to claim 1, characterized in that, The carrier material includes at least one of silicon dioxide and aluminum oxide.

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