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CN-121992433-A - Catalyst for producing hydrogen peroxide from seawater and preparation method and application thereof

CN121992433ACN 121992433 ACN121992433 ACN 121992433ACN-121992433-A

Abstract

The invention provides a catalyst for marine hydrogen peroxide, a preparation method and application thereof, the catalyst of the invention, the carbon dots are used as a carrier of the catalyst, nickel is dispersed on the surface of the carbon dots in a form of monoatoms, and the monoatoms of the nickel coordinate with nitrogen atoms of the carbon dots. The catalyst provided by the invention has high activity, high selectivity (Faraday efficiency is highest > 98%) and excellent long-term stability for preparing hydrogen peroxide by two-electron oxygen reduction reaction in seawater or simulated seawater electrolyte, and provides a high-efficiency and stable catalyst solution for synthesizing hydrogen peroxide in a distributed manner by utilizing seawater resources.

Inventors

  • DING SHIHU
  • WANG WEI
  • ZHOU MINGHUA

Assignees

  • 南开大学

Dates

Publication Date
20260508
Application Date
20260316

Claims (10)

  1. 1. A catalyst for producing hydrogen peroxide from seawater is characterized in that carbon dots are used as a carrier of the catalyst, nickel is dispersed on the surface of the carbon dots in a form of monoatoms, and the monoatoms of the nickel coordinate with nitrogen atoms of the carbon dots.
  2. 2. The catalyst for marine hydrogen peroxide according to claim 1, wherein the surface of the carbon dot contains at least one nitrogen-containing functional group selected from the group consisting of amino groups, pyridine nitrogen and graphite nitrogen, and preferably the surface of the carbon dot further contains at least one oxygen-containing functional group selected from the group consisting of carbonyl groups, carboxyl groups and hydroxyl groups.
  3. 3. A process for preparing a catalyst for seawater production of hydrogen peroxide as claimed in claim 1 or 2, characterized by comprising the steps of, 1) Dissolving nickel salt and carbon dots in deionized water, and mixing to obtain a mixed solution; 2) Adding a nitrogen-containing organic ligand into the mixed solution obtained in the step 1), performing ultrasonic dispersion to fully coordinate nickel ions with nitrogen-containing functional groups on the surface of the carbon dots, and then performing freeze drying to obtain a gas gel precursor; 3) Collecting the aerogel precursor in the step 2), introducing a protective gas, and pyrolyzing at a specific temperature for a certain time to obtain the nickel monoatomic catalyst, namely the catalyst for producing hydrogen peroxide from seawater.
  4. 4. The method for preparing the catalyst for marine product hydrogen peroxide according to claim 3, wherein in the step 1), the nickel salt is one or more of nickel acetate tetrahydrate, nickel chloride and nickel acetylacetonate, the nitrogen-containing organic ligand is one or more of dinitrile amine, melamine and urea, and in the step 1), the mass ratio of the nickel salt to the carbon point to the nitrogen-containing organic ligand is 1 (1-5): (10-30), and the content of the nickel salt in deionized water is 0.1-2 mg/mL.
  5. 5. The method for preparing the catalyst for the marine product hydrogen peroxide according to claim 3, wherein the mixing in the step 1) is ultrasonic dispersion mixing, the ultrasonic dispersion frequency is 30-50 kHz, the time is 10-120 min, the ultrasonic dispersion frequency in the step 2) is 30-50 kHz, the time is 10-120 min, the freeze drying temperature is-45 to-55 ℃, the pressure is 1-20 Pa, and the time is 12-36 h.
  6. 6. The method for preparing a catalyst for marine hydrogen peroxide according to claim 3, wherein in the step 3), the shielding gas is argon or nitrogen, the gas flow rate is 20-100 cm 3 /min, the pyrolysis temperature is 300-700 ℃, the heating rate is 2-5 ℃/min, and the heating time is 1-3 h.
  7. 7. The method for preparing a catalyst for marine product hydrogen peroxide according to claim 3, wherein the method for preparing the carbon dots in the step 1) comprises the steps of, Dissolving citric acid and urea in ethylene glycol, stirring, heating, filtering, dialyzing with deionized water as dialysis external liquid, and freeze-drying the dialysis liquid to obtain carbon dot powder, wherein the molar ratio of the citric acid to the urea to the ethylene glycol is 1 (1-3) (40-80), the heating temperature is 120-240 ℃, the heating time is 2-24 h, the diameter of a filter membrane used for filtering is 0.1-0.5 mu m, the deionized water content of the dialysis external liquid used for dialysis is 800-1500 mL, the dialysis time is 2-72 h, the dialysis external liquid replacement time is 2-4 times every 24h, and the freeze-drying time is 12-48 h.
  8. 8. Use of the catalyst for seawater hydrogen peroxide production according to claim 1 or 2 or the catalyst prepared by the preparation method according to any one of claims 3 to 7 in the electrocatalytic preparation of hydrogen peroxide.
  9. 9. The method according to claim 8, wherein the electrocatalytic electrolyte is seawater, simulated seawater or alkaline sodium chloride solution.
  10. 10. The method of claim 8, wherein the electrocatalytic hydrogen peroxide production has an operating current density of 10-200 mA/cm 2 .

Description

Catalyst for producing hydrogen peroxide from seawater and preparation method and application thereof Technical Field The invention belongs to the technical field of electrocatalytic materials and new energy, and particularly relates to a catalyst for producing hydrogen peroxide from seawater as well as a preparation method and application thereof. Background Hydrogen peroxide (H 2O2) is a global important chemical, is a multifunctional green oxidant, is widely used in the fields of environmental remediation, pulp bleaching, chemical synthesis and the like, and has the potential as an energy carrier. However, the industrial scale production of H 2O2 still relies heavily on the high energy consumption of the anthraquinone oxidation process. The process not only requires the consumption of organic solvents and noble metal catalysts, but also presents challenges for the application of the distributed system. Direct electrosynthesis of H 2O2 by two-electron oxygen reduction has become a very promising sustainable alternative. The electrochemical method takes water and air as raw materials, can be driven by renewable energy sources, and can realize modularized, on-demand and on-demand H 2O2 production. 2E - ORR (two electron oxygen reduction reaction) for the production of H 2O2 involves two successive proton-coupled electron transfer steps, in which(Adsorbed peroxyhydroxy) is the only reaction intermediate. Although in spite ofDissociation is thermodynamically more advantageous than the formation of H 2O2, but nickel-based monoatomic catalysts with isolated active sites have proven to overcome this limitation, which limits oxygen adsorption to the end-to-end configuration, thus stabilizingIntermediate and prevents cleavage of O-O bonds. In addition, the d electron orbitals of Ni can be realizedBalancing O 2 activation and H 2O2 desorption to selectively direct the reaction toward the efficient 2e - pathway to form H 2O2. However, metal monoatoms are easy to migrate and agglomerate in the preparation or reaction process, so that the metal monoatoms are deactivated, and meanwhile, complex ionic environments (such as Cl -) in seawater are easy to erode catalytic sites, so that the stability of the metal monoatoms is damaged. Therefore, the development of a novel carbon-point-based single-atom catalyst suitable for severe seawater environment and a specific anchoring preparation method thereof has important scientific significance and application value. Disclosure of Invention In view of the above, the invention aims to provide a catalyst for producing hydrogen peroxide from seawater, a preparation method and application thereof, so as to overcome the defects of the prior art and provide a catalyst with stable structure and definite active site. The carbon dots anchor the nickel monoatomic catalyst. The catalyst shows high activity, high selectivity and excellent long-term stability for preparing H 2O2 from 2e - ORR in seawater or simulated seawater electrolyte. Meanwhile, the invention provides a specific preparation method of the catalyst, which can realize the anchoring of nickel atoms on the surface of carbon points. In order to achieve the above purpose, the technical scheme of the invention is realized as follows: In a first aspect, a catalyst for producing hydrogen peroxide from seawater, wherein carbon dots are used as a carrier of the catalyst, nickel is dispersed on the surface of the carbon dots in the form of monoatoms, and the monoatoms of nickel coordinate with nitrogen atoms of the carbon dots. As a further scheme, the surface of the carbon dot contains at least one nitrogen-containing functional group of amino, pyridine nitrogen and graphite nitrogen; as a further preferable scheme, the surface of the carbon dot also contains at least one oxygen-containing functional group of carbonyl, carboxyl and hydroxyl. In a second aspect, the invention provides a method for preparing a catalyst for producing hydrogen peroxide from seawater, comprising the steps of, 1) Dissolving nickel salt, carbon dots and nitrogen-containing organic ligand in deionized water, and fully stirring and mixing to obtain a mixed solution; 2) Ultrasonically dispersing the mixed solution obtained in the step 1) to fully coordinate nickel ions with nitrogen-containing functional groups on the surface of the carbon dots, and then freeze-drying to obtain a gas gel precursor; 3) Collecting the aerogel precursor in the step 2), introducing a protective gas, and pyrolyzing at a specific temperature for a certain time to obtain the nickel monoatomic catalyst, namely the catalyst for producing hydrogen peroxide from seawater. In the step 1), the nickel salt is one or more than two of nickel acetate tetrahydrate, nickel chloride and nickel acetylacetonate, and the nitrogen-containing organic ligand is one or more than two of dinitrile amine, melamine and urea. In the step 1), the mass ratio of the nickel salt to the carbon dots to the nitrog