Search

CN-122013219-A - Preparation method of catalytic electrode and application of catalytic electrode in photoelectrocatalytic reduction of nitrogen

CN122013219ACN 122013219 ACN122013219 ACN 122013219ACN-122013219-A

Abstract

The invention discloses a preparation method of a catalytic electrode, which comprises the following steps of S1, weighing anode catalyst powder and cathode catalyst powder, dispersing the anode catalyst powder and the cathode catalyst powder in a solvent respectively, adding Nafion solution, uniformly dispersing the materials by ultrasonic to prepare anode catalyst slurry and cathode catalyst slurry, S2, taking a gas diffusion layer, placing the gas diffusion layer on a platform heating table for heating, S3, weighing anode catalyst slurry or cathode catalyst slurry, uniformly spraying the anode catalyst slurry or cathode catalyst slurry on the gas diffusion layer, and drying the gas diffusion layer in an inert atmosphere to prepare an anode gas diffusion electrode and a cathode gas diffusion electrode, and further discloses application of the anode gas diffusion electrode and the cathode gas diffusion electrode prepared in the method as an anode and a cathode of an electrolytic cell in photoelectrocatalytic reduction nitrogen respectively for preparing ammonia.

Inventors

  • LIU ZHENPENG
  • LI XIN

Assignees

  • 西安航空学院

Dates

Publication Date
20260512
Application Date
20260303
Priority Date
20260209

Claims (10)

  1. 1. A method for preparing a catalytic electrode, comprising the steps of: s1, anode catalyst powder and cathode catalyst powder are weighed and respectively dispersed in a solvent, and Nafion solution is added and then uniformly dispersed by ultrasonic to prepare anode catalyst slurry and cathode catalyst slurry; s2, taking the gas diffusion layer and placing the gas diffusion layer on a platform heating table, and heating to 50-100 ℃; S3, weighing anode catalyst slurry or cathode catalyst slurry, uniformly spraying the anode catalyst slurry or the cathode catalyst slurry on the gas diffusion layer, and drying the gas diffusion layer in an inert atmosphere to obtain the anode gas diffusion electrode and the cathode gas diffusion electrode.
  2. 2. The method of claim 1, wherein the anode catalyst powder comprises one of Fe, co, ni, ir, ru metal or metal oxide based catalyst or nickel foam.
  3. 3. The method for preparing a catalytic electrode according to claim 1, wherein the cathode catalyst powder comprises one of a boron doped diamond catalyst, a bismuth oxyhalide catalyst, a titania-based catalyst, a layered double hydroxide catalyst, and a graphite carbonitride catalyst.
  4. 4. The method for producing a catalytic electrode according to claim 3, wherein the bismuth oxyhalide-based catalyst comprises one or more of BiOBr, biOCl, bi 5 O 7 I、Bi 5 O 7 Br and the graphite carbonitride catalyst comprises one or more of V-g-C 3 N 4 、g-C 3 N 4 /rGO、S-doped g-C 3 N 4 、g-C 3 N 4 /ZnMoCdS、Fe-doped g-C 3 N 4 、Ga 2 O 3 -DBD/g-C 3 N 4 、TiO 2 @C/g-C 3 N 4 、g-C 3 N 4 /MgAlFeO NRs.
  5. 5. The method for preparing the catalytic electrode according to claim 1, wherein the solvent comprises absolute ethyl alcohol, isopropanol or a mixed solution of isopropanol and deionized water in equal volume, the concentration of the catalytic electrode powder after being dissolved in the solvent is 0.5-10 g/L, the mass fraction of the Nafion solution is 5 wt-20 wt%, and the volume ratio of the Nafion solution to the solvent is 1:20-1:5.
  6. 6. The method of manufacturing a catalytic electrode according to claim 1, wherein the gas diffusion layer material comprises carbon fiber paper, carbon fiber woven cloth, non-woven cloth or carbon black paper.
  7. 7. The method for preparing a catalytic electrode according to claim 1, wherein the anode catalyst slurry and the cathode catalyst slurry are sprayed in the step S3 to have a loading capacity of 0.005-10 mg cm －2 .
  8. 8. Use of an anode gas diffusion electrode and a cathode gas diffusion electrode prepared by the method for preparing a catalytic electrode according to any one of claims 1 to 7 as anode and cathode, respectively, of an electrolytic cell in photoelectrocatalytic reduction of nitrogen.
  9. 9. The method according to claim 8, wherein the anode gas diffusion electrode is inserted into an anode chamber of an electrolytic cell, and the cathode gas diffusion electrode is inserted into a cathode chamber of the electrolytic cell, wherein the anode chamber and the cathode chamber are respectively filled with an anolyte and a catholyte; a gas chamber is arranged at one side of the electrolytic cell, and the gas in the gas chamber can be contacted with a cathode gas diffusion electrode; Continuous flow of anolyte and catholyte is provided to the anode chamber and the cathode chamber, respectively, while continuous flow of nitrogen is provided to the gas chamber.
  10. 10. The application of the solar cell module according to claim 9, wherein the flow rate of nitrogen is 5-100 sccm, the flow rates of catholyte and anolyte are 1-100 sccm, a direct current regulated power supply with the voltage of 0.2-2.0V is adopted between an anode gas diffusion electrode and a cathode gas diffusion electrode to supply power, and one or more of sunlight, two sunlight, ultraviolet light, infrared light and visible light are adopted as the illumination window.

Description

Preparation method of catalytic electrode and application of catalytic electrode in photoelectrocatalytic reduction of nitrogen Technical Field The invention belongs to the technical field of photoelectrocatalytic reduction of nitrogen, and relates to a preparation method of a catalytic electrode and application of the catalytic electrode in photoelectrocatalytic reduction of nitrogen. Background Ammonia (NH 3) is one of the most important chemical products in the world, not only can be used for synthesizing artificial fertilizer and providing sufficient grain supply for human society, but also can be used as an important energy carrier and storage intermediate due to high energy density (one third of diesel oil) and convenient transportation, and is a high-efficiency renewable fuel. Nitrogen (N 2) in the air accounts for about 78%, and if the nitrogen can reduce and convert the ubiquitous N 2 in the air into NH 3 with more economic and practical values, the fertilizer and industrial development problems can be solved. Currently, the industrial NH 3 production mainly uses the Haber-Bosch process, i.e. the conversion of ammonia (NH 3) is achieved at high temperature (400-500 ℃), high pressure (200-300 atm) and in the presence of a catalyst (Fe or Ru-based), whereas the kinetics of this reaction are slow, high temperatures are required to accelerate the reaction, the annual energy consumption of NH 3 production is more than 1% of the annual total world energy consumption, with a concomitant emission of 400Mt carbon dioxide each year. Therefore, there is a need to develop a mild, green, efficient, sustainable ammonia synthesis technology to replace the traditional Haber-Bosch process. Catalytic and photoelectrocatalytic processes are considered energy-efficient and environmentally benign NH3 production processes that can produce ammonia directly from air and water using solar energy under ambient conditions, however, photocatalytic nitrogen reduction is less efficient than photoelectrocatalytic nitrogen reduction because photocatalysis occurs on particle surfaces due to redox reactions, which are highly prone to photo-generated electron-hole recombination, not all photons being available for the photocatalytic process, reducing efficiency. Under the condition of applying bias voltage, the photoelectrocatalysis can effectively enhance the carrier migration rate of the photoelectrocatalyst, and improve the electron hole separation efficiency and the photoelectrocatalysis nitrogen reduction performance. Thus, photoelectrocatalytic nitrogen reduction (NRR) is an extremely efficient approach to achieve clean, energy efficient and sustainable development of N 2 and H 2 O conversion to NH 3. Specifically, the photoelectrocatalytic nitrogen reduction (NRR) mainly comprises three steps of (1) nitrogen adsorption, wherein the surface of a catalyst is provided with enough nitrogen adsorption sites for fixing nitrogen, and (2) photon excitation, wherein the catalyst generates photoexcitation electrons (e-) after absorbing light energy. The photo-generated electrons are excited and migrate to the Conduction Band (CB) to leave holes in the Valence Band (VB), and (3) some photo-generated electron-hole recombination exists, and some electrons and holes migrate to the surface of the catalyst to participate in the oxidation-reduction reaction. Currently, in the prior art, chinese patent publication No. CN108842163a discloses an application of a bipolar membrane with a copper-metal organic framework material as an intermediate interface layer in photoelectrocatalysis nitrogen fixation, wherein the application is to prepare an ionic liquid electrolyte solution with a bipolar membrane with a copper-metal organic framework material in the intermediate interface layer as a diaphragm of a cathode chamber and an anode chamber, with a metal and an oxide thereof as an anode, and with a semiconductor material and a transition metal oxide as a cathode, fixing nitrogen and reducing the nitrogen to ammonia under photoelectrocatalysis. Also, chinese patent publication No. CN109082682a discloses an application of a bipolar membrane with zinc-metal organic framework material as an intermediate interface layer in photocatalytically fixing nitrogen, wherein the application is to prepare an ionic liquid electrolyte solution with the bipolar membrane with zinc-metal organic framework material in the intermediate interface layer as a diaphragm of a cathode chamber and an anode chamber, metal and its oxide as an anode, and semiconductor material and transition metal oxide as a cathode, and fix and reduce nitrogen to ammonia under the action of photocatalysts. However, in the prior art, the conventional single-compartment or double-compartment H-type photoelectrochemical reaction cell is adopted, and the dissolution and diffusion of nitrogen in the electrolyte are limited, so that the mass transfer efficiency of nitrogen molecules is limited, and the