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CN-122013218-A - Metal-loaded superhydrophobic air electrode for chlorine production reaction and preparation method thereof

CN122013218ACN 122013218 ACN122013218 ACN 122013218ACN-122013218-A

Abstract

The application relates to the technical field of air electrodes, in particular to a metal-loaded super-hydrophobic air electrode for chlorine production reaction and a preparation method thereof, comprising a porous composite matrix, a porous ceramic matrix and a porous ceramic matrix, wherein the porous composite matrix consists of a three-dimensional porous ceramic skeleton and an MXene nano-sheet conductive network attached to the pore canal and the surface of the porous ceramic skeleton; the gradient functional super-hydrophobic layer is formed by compounding polytetrafluoroethylene and a fluorine-containing polymer formed by in-situ polymerization of fluorine-containing acrylate monomers, and the metal catalyst layer is directly supported on the surface of the gradient functional super-hydrophobic layer. The application realizes the performance improvement from the aspects of charge transmission, three-phase interface mass transfer, catalytic activity and selectivity, structure corrosion resistance durability and the like by constructing an MXene two-dimensional conductive network in situ on a ceramic skeleton, constructing a composite functional layer with gradient change of components and wettability and forming strong metal-carrier interaction by using MXene and noble metal.

Inventors

  • LU DINGNAN
  • SUN WEI
  • GAN HUIHUI

Assignees

  • 宁波大学

Dates

Publication Date
20260512
Application Date
20260205

Claims (10)

  1. 1.A metal-supported superhydrophobic air electrode for a chlorine generating reaction, the air electrode comprising: the porous composite matrix consists of a three-dimensional porous ceramic skeleton and an MXene nano sheet conductive network attached to the pore canal and the surface of the porous composite matrix; A gradient functional super-hydrophobic layer covering the surface of the porous composite matrix, wherein the gradient functional super-hydrophobic layer is formed by compounding polytetrafluoroethylene and fluorine-containing polymer formed by in-situ polymerization of fluorine-containing acrylate monomers, the chemical components and the surface energy of the gradient functional super-hydrophobic layer are changed in a gradient manner from the side of the matrix to the side of the outer surface so that the electrode has super-hydrophobicity, and And the metal catalyst layer is directly supported on the surface of the gradient functional super-hydrophobic layer.
  2. 2. The metal-supported superhydrophobic air electrode for chlorine generating reaction of claim 1, wherein the porous composite substrate is prepared by a method comprising: Using organic foam as a sacrificial template, dipping sol containing a ceramic precursor and a sintering aid, and drying and sintering at high temperature to form a porous ceramic skeleton with a three-dimensional through network structure; Selectively etching by using MAX phase powder as a raw material and adopting hydrochloric acid solution or hydrofluoric acid solution containing lithium fluoride to remove an aluminum atomic layer, washing an etching product to be neutral, then performing intercalation treatment by using an organic amine intercalation agent, then performing liquid-phase ultrasonic stripping under a protective atmosphere, and removing an unpeeled thick sheet by centrifugal separation to obtain a stable dispersion liquid of single-layer or less-layer MXene nano sheets; Placing the porous ceramic skeleton in a closed container, vacuumizing, then injecting the MXene dispersion liquid, driving the dispersion liquid by negative pressure to completely infiltrate the skeleton pores, taking out, drying to enable the MXene nano-sheets to be attached to the surface of the ceramic skeleton, and performing heat treatment under the protection of inert atmosphere, wherein the heat treatment temperature is 200-500 ℃, thus obtaining the porous composite matrix.
  3. 3. The metal-supported superhydrophobic air electrode for chlorine generating reaction of claim 2, wherein the MAX phase powder is at least one of Ti 3 AlC 2 、Ti 2 AlC or Nb 2 AlC, the ceramic precursor is at least one of zirconia, titania or alumina, and the organic amine intercalating agent is selected from dimethyl sulfoxide, tetrabutylammonium hydroxide or tetramethylammonium hydroxide.
  4. 4. The metal-supported superhydrophobic air electrode for chlorine generating reaction of claim 1, wherein the metal catalyst layer comprises at least one noble metal selected from platinum, palladium, iridium, ruthenium, gold, or an alloy of the noble metal and at least one transition metal of iron, cobalt, nickel, copper.
  5. 5. The metal-supported superhydrophobic air electrode for chlorine generating reaction of claim 1, wherein the gradient functionalized superhydrophobic layer is formed by dipping the porous composite substrate in a composite functional slurry, triggering in-situ polymerization of the monomer to form a fluoropolymer network, and then performing a heat treatment at 300 ℃ to 380 ℃ to melt polytetrafluoroethylene and fuse with the polymer network to obtain the gradient functionalized superhydrophobic layer.
  6. 6. The metal-supported superhydrophobic air electrode for chlorine generating reaction of claim 5, wherein the composite functional slurry comprises polytetrafluoroethylene dispersion, polymerizable fluoroacrylate monomer and initiator, wherein the polymerizable fluoroacrylate monomer is dodecafluoroheptyl methacrylate, and the polymerization initiator is an ultraviolet initiator or a thermal initiator.
  7. 7. A method for preparing the metal-supported superhydrophobic air electrode for chlorine generating reaction of any one of claims 1-6, comprising the steps of: preparing an MXene composite porous matrix, and cleaning and drying the porous matrix to obtain a pretreated substrate; Immersing the pretreated matrix into composite functional slurry, taking out and draining, triggering in-situ polymerization reaction under the action of an initiator, and then performing heat treatment at the temperature of 300-380 ℃ to form a gradient functional super-hydrophobic layer; Carrying out surface activation treatment on the matrix covered with the super-hydrophobic layer; And (3) taking the activated matrix as a working electrode, performing electrochemical deposition in electrolyte containing target metal ions to form a metal catalyst layer, coating a perfluorinated sulfonic acid resin solution on the surface of the metal catalyst layer, and drying again to obtain the metal-supported super-hydrophobic air electrode.
  8. 8. The method for preparing the metal-supported super-hydrophobic air electrode for chlorine generating reaction according to claim 7, wherein the surface activation treatment is corona treatment, and the treatment conditions comprise 10-48kV voltage, 5-10mm electrode spacing and 30-150 seconds.
  9. 9. The method for preparing the metal-supported super-hydrophobic air electrode for chlorine generating reaction according to claim 7, wherein the electrochemical deposition adopts a potentiostatic deposition method, the deposition potential is-0.5V to +0.5V relative to an Ag/AgCl reference electrode, the deposition is carried out under the protection of nitrogen, and the deposition time is 10-30 minutes.
  10. 10. The preparation method of the metal-supported super-hydrophobic air electrode for chlorine generating reaction according to claim 9, wherein the metal precursor in the electrolyte is at least one selected from chloroplatinic acid, chloropalladic acid, palladium chloride, iridium chloride, ruthenium trichloride, silver nitrate, copper sulfate, cobalt chloride, nickel nitrate and ferric chloride, the electrolyte is an aqueous solution of inorganic acid or organic acid, the inorganic acid is at least one selected from hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, and the organic acid is at least one selected from formic acid, acetic acid and oxalic acid.

Description

Metal-loaded superhydrophobic air electrode for chlorine production reaction and preparation method thereof Technical Field The invention relates to the technical field of air electrodes, in particular to a metal-loaded superhydrophobic air electrode for chlorine production reaction and a preparation method thereof. Background The electrochemical chlorine production technology has important application in the fields of disinfection, wastewater treatment, chemical synthesis and the like. Gas diffusion electrodes (also known as air electrodes) are the core components in these, whose performance directly determines the efficiency, energy consumption and lifetime of the system. The ideal air electrode for chlorine production has the following characteristics of (1) high conductivity to reduce ohmic polarization, (2) proper hydrophobicity to construct a stable gas-liquid-solid three-phase reaction interface to promote chlorine precipitation, (3) high catalytic activity and stability, and (4) firm mechanical structure and interface combination to resist scouring and corrosion in the long-term electrolysis process. At present, common air electrodes are mostly made of porous conductive materials such as carbon paper, foam nickel and the like as matrixes, and are made of binding agents such as Polytetrafluoroethylene (PTFE) and catalytic materials through coating or sintering. The electrode has the inherent defects that firstly, a carbon material is easy to corrode under the strong oxidative chlorine-generating potential to cause electrode structure collapse and performance attenuation, and secondly, the PTFE and a conductive matrix are mainly physically attached, the interface binding force is weak, and a hydrophobic layer is easy to peel off under long-term operation or high gas flux to cause the electrode to be "drowned" and deactivated by electrolyte. In addition, the traditional preparation method has limited control on the microstructure of the electrode, and is difficult to accurately construct a tough and stable superhydrophobic interface while ensuring high conductivity. Disclosure of Invention The application provides a metal-loaded super-hydrophobic air electrode for chlorine production reaction and a preparation method thereof, which are used for solving the problems of easy corrosion of a carbon matrix, weak interface combination, difficult regulation and control of a structure, easy attenuation and inactivation of performance and the like in the prior art. In order to achieve the purpose, the invention adopts the following technical scheme that the invention provides a metal-loaded super-hydrophobic air electrode for chlorine production reaction, which comprises the following components: the porous composite matrix consists of a three-dimensional porous ceramic skeleton and an MXene nano sheet conductive network attached to the pore canal and the surface of the porous composite matrix; A gradient functional super-hydrophobic layer covering the surface of the porous composite matrix, wherein the gradient functional super-hydrophobic layer is formed by compounding polytetrafluoroethylene and fluorine-containing polymer formed by in-situ polymerization of fluorine-containing acrylate monomers, the chemical components and the surface energy of the gradient functional super-hydrophobic layer are changed in a gradient manner from the side of the matrix to the side of the outer surface so that the electrode has super-hydrophobicity, and And the metal catalyst layer is directly supported on the surface of the gradient functional super-hydrophobic layer. Preferably, the porous composite matrix is prepared by a process comprising the steps of: Using organic foam as a sacrificial template, dipping sol containing a ceramic precursor and a sintering aid, and drying and sintering at high temperature to form a porous ceramic skeleton with a three-dimensional through network structure; Selectively etching by using MAX phase powder as a raw material and adopting hydrochloric acid solution or hydrofluoric acid solution containing lithium fluoride to remove an aluminum atomic layer, washing an etching product to be neutral, then performing intercalation treatment by using an organic amine intercalation agent, then performing liquid-phase ultrasonic stripping under a protective atmosphere, and removing an unpeeled thick sheet by centrifugal separation to obtain a stable dispersion liquid of single-layer or less-layer MXene nano sheets; Placing the porous ceramic skeleton in a closed container, vacuumizing, then injecting the MXene dispersion liquid, driving the dispersion liquid by negative pressure to completely infiltrate the skeleton pores, taking out, drying to enable the MXene nano-sheets to be attached to the surface of the ceramic skeleton, and performing heat treatment under the protection of inert atmosphere, wherein the heat treatment temperature is 200-500 ℃, thus obtaining the porous composite matrix. Preferab