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CN-122006705-A - Three-dimensional core-shell structure catalyst for hydrogen energy storage and preparation method thereof

CN122006705ACN 122006705 ACN122006705 ACN 122006705ACN-122006705-A

Abstract

The invention discloses a preparation method of a three-dimensional core-shell structure catalyst for hydrogen energy storage, which specifically comprises the following steps of 1, preparing a lamellar Ti 3 C 2 T x , 2, preparing modified silicon spheres, and 3, preparing the three-dimensional core-shell structure catalyst according to the products obtained in the steps 1 and 2. The invention also discloses a three-dimensional core-shell structure catalyst for hydrogen energy storage, and the catalyst prepared by the method can realize stable dehydrogenation at high temperature (350 ℃) and improve the dehydrogenation efficiency.

Inventors

  • ZHANG ZHAO
  • MA YUEER
  • CHANG HUI

Assignees

  • 陕西科技大学

Dates

Publication Date
20260512
Application Date
20260129

Claims (8)

  1. 1. The preparation method of the three-dimensional core-shell structure catalyst for hydrogen energy storage is characterized by comprising the following steps of: Step 1, preparing Ti 3 C 2 T x of a sheet layer; Step2, preparing modified silicon spheres; And 3, preparing the three-dimensional core-shell structure catalyst according to the products obtained in the step 1 and the step 2.
  2. 2. The method for preparing the three-dimensional core-shell structure catalyst for hydrogen energy storage according to claim 1, wherein the specific process of the step 1 is as follows: 1.1, respectively weighing 1.6-2.4 g of LiF powder, 15-30 mL of concentrated hydrochloric acid and 5-10 mL of deionized water; Step 1.2, pouring the LiF powder, deionized water and concentrated hydrochloric acid weighed in the step 1.1 into a polytetrafluoroethylene bottle, and heating the mixture to 45-65 ℃ by using a magnetic stirrer to fully dissolve the LiF powder in the hydrochloric acid to obtain a LiF/HCl mixed solution; And 1.3, adding 1-1.5 g of Ti 3 AlC 2 MAX phase powder into LiF/HCl mixed solution, stirring and etching for 24-48 hours, pouring the reaction liquid into a plastic centrifuge tube after the reaction is completed, washing with deionized water, centrifuging for 5-15 minutes, pouring out supernatant, adding deionized water, centrifuging again, repeatedly washing until the pH of the supernatant is neutral, discarding the supernatant, dispersing the precipitate in 100-200 mL of deionized water, performing ultrasonic treatment in an ice water bath for 2-3 hours, centrifuging the dispersion, taking dark green supernatant, namely a single-layer Ti 3 C 2 T x dispersion, and freeze-drying the dispersion for 24-48 hours to obtain the Ti 3 C 2 T x in a sheet.
  3. 3. The method for preparing a three-dimensional core-shell structure catalyst for hydrogen energy storage according to claim 2, wherein in the step 1.3, the rotation speed of stirring etching is 350 rpm-650 rpm.
  4. 4. The method of preparing a three-dimensional core-shell catalyst for hydrogen energy storage according to claim 2, wherein in the step 1.3, the rotational speed of the reaction solution after washing with deionized water is 3500 rpm~5500 rpm.
  5. 5. The method for preparing a three-dimensional core-shell structure catalyst for hydrogen energy storage according to claim 2, wherein in the step 1.3, ultrasonic power during ultrasonic treatment is 200W-300W.
  6. 6. The preparation method of the three-dimensional core-shell structure catalyst for hydrogen energy storage according to claim 2, wherein the specific process of the step 2 is as follows: step 2.1, adding TEOS into absolute ethyl alcohol to prepare a solution A; Step 2.2, adding NH 4 (OH) into ethanol to prepare a solution B; step 2.3, respectively magnetically stirring the solution A prepared in the step 2.1 and the solution B prepared in the step 2.2, then dropwise adding the solution A into the solution B, stirring the mixture for 6-12 h, centrifugally washing the obtained product with distilled water, and then drying overnight to obtain silica spheres; step 2.4, dispersing the silica spheres prepared in the step 2.3 in ethanol, and performing ultrasonic dispersion; Step 2.5, dissolving the 3-ATPS in an ethanol water solution, and stirring for 0.5-1 hour; And 2.6, magnetically stirring the silica ultrasonically dispersed in the step 2.4 for 0.5-1 hour under a nitrogen atmosphere, adding the hydrolysis product 3-ATPS in the step 2.5, reacting for 8-16 hours, washing the obtained solution with deionized water and ethanol respectively, centrifuging for three times, and then drying in vacuum to obtain the modified silica.
  7. 7. The method for preparing the three-dimensional core-shell structure catalyst for hydrogen energy storage according to claim 6, wherein the specific process of the step 3 is as follows: step 3.1, respectively dispersing the modified silicon dioxide and Ti 3 C 2 T x obtained in the step 2 in deionized water, and carrying out ultrasonic treatment for 30-60 min to obtain a uniformly dispersed silicon dioxide solution and a Ti 3 C 2 T x solution; Step 3.2, silica solution, H 2 PtCl 6 Adding 6H 2 O solution into Ti 3 C 2 T x solution, performing ultrasonic treatment, and oscillating overnight in a gas bath shaker; and 3.3, placing the product obtained in the step 3.2 in a tube furnace, and carrying out reduction reaction in argon-hydrogen mixed gas to obtain the prepared three-dimensional core-shell structure.
  8. 8. A three-dimensional core-shell structure catalyst for hydrogen energy storage, which is prepared by the preparation method of the three-dimensional core-shell structure catalyst for hydrogen energy storage according to any one of claims 1 to 7.

Description

Three-dimensional core-shell structure catalyst for hydrogen energy storage and preparation method thereof Technical Field The invention belongs to the technical field of organic hydrogen carrier (LOHC) dehydrogenation, relates to a three-dimensional core-shell structure catalyst for hydrogen energy storage, and further relates to a preparation method of the three-dimensional core-shell structure catalyst for hydrogen energy storage. Background Liquid organic hydrogen storage (LOHC) provides an alternative route for the safe, normal temperature and pressure storage and transportation of hydrogen, with Methylcyclohexane (MCH) being representative due to its high stability, compatibility with existing infrastructure, and high hydrogen storage density. MCH dehydrogenation belongs to a high-temperature gas-solid multiphase reaction, reactants enter and are separated from products (H 2/toluene) in the reaction process, heat transfer and mass transfer of a bed layer are mutually coupled, diffusion limitation and local heat accumulation are easy to occur, and side reaction and carbon deposition risks are further amplified. Thus, the catalyst not only requires high activity and high C-H selectivity, but also must maintain site accessibility and structural stability under high temperature long term operation. Pt systems have excellent selectivity potential in LOHC dehydrogenation, but the cost and scarcity requirements of Pt systems are reduced, the atomic utilization rate is improved, however, the utilization rate of Pt with the existing single atom/ultra-small cluster can be improved, but the Pt with the existing single atom/ultra-small cluster has inherent dynamic instability at high temperature due to a low coordination structure, and the Pt is easy to migrate and agglomerate to cause activity attenuation. The traditional oxide carrier has limited anchoring strength and sintering resistance to Pt, and the Pt is often induced to grow up by only relying on oxygen coordination and is accompanied by more low-activity high-valence species, so that low load is caused, but effective sites are insufficient. Although the micropore/mesopore confinement can enhance stability, it often comes at the expense of site exposure, diffusion efficiency and heat transfer efficiency, resulting in difficulty in simultaneously ensuring stability and dehydrogenation efficiency. The two-dimensional MXene serving as a potential carrier has abundant defects and surface functional groups, can provide a large number of anchoring sites, but the sheets are easy to self-accumulate, so that active sites are shielded, interface charges and transmission channels are blocked, and the diffusion and heat transfer problems in the dehydrogenation process are further aggravated. Disclosure of Invention The invention aims to provide a preparation method of a three-dimensional core-shell structure catalyst for hydrogen energy storage, and the catalyst prepared by the method can realize stable dehydrogenation at high temperature (350 ℃) and improve the dehydrogenation efficiency. It is another object of the present invention to provide a three-dimensional core-shell structured catalyst for hydrogen energy storage. The first technical scheme adopted by the invention is that the preparation method of the three-dimensional core-shell structure catalyst for hydrogen energy storage specifically comprises the following steps: Step 1, preparing Ti 3C2Tx of a sheet layer; Step2, preparing modified silicon spheres; And 3, preparing the three-dimensional core-shell structure catalyst according to the products obtained in the step 1 and the step 2. The first technical scheme of the invention is characterized in that: the specific process of the step1 is as follows: 1.1, respectively weighing 1.6-2.4 g of LiF powder, 15-30 mL of concentrated hydrochloric acid and 5-10 mL of deionized water; Step 1.2, pouring the LiF powder, deionized water and concentrated hydrochloric acid weighed in the step 1.1 into a polytetrafluoroethylene bottle, and heating the mixture to 45-65 ℃ by using a magnetic stirrer to fully dissolve the LiF powder in the hydrochloric acid to obtain a LiF/HCl mixed solution; And 1.3, adding 1-1.5 g of Ti 3AlC2 MAX phase powder into LiF/HCl mixed solution, stirring and etching for 24-48 hours, pouring the reaction liquid into a plastic centrifuge tube after the reaction is completed, washing with deionized water, centrifuging for 5-15 minutes, pouring out supernatant, adding deionized water, centrifuging again, repeatedly washing until the pH of the supernatant is neutral, discarding the supernatant, dispersing the precipitate in 100-200 mL of deionized water, performing ultrasonic treatment in an ice water bath for 2-3 hours, centrifuging the dispersion, taking dark green supernatant, namely a single-layer Ti 3C2Tx dispersion, and freeze-drying the dispersion for 24-48 hours to obtain the Ti 3C2Tx in a sheet. In the step 1.3, the rotation speed of stirr