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CN-122013238-A - Preparation method of self-supporting anode catalyst, catalyst and application of catalyst

CN122013238ACN 122013238 ACN122013238 ACN 122013238ACN-122013238-A

Abstract

The invention provides a preparation method of a self-supporting anode catalyst, the catalyst and application thereof, and relates to the technical field of electrolytic water oxygen evolution catalysts; immersing the pretreated foam nickel-iron substrate into a first precursor solution for standing reaction, growing in situ on the surface of the substrate to form a transition metal sulfide layer, washing and drying to obtain an intermediate product, placing the intermediate product into a second precursor solution for hydrothermal reaction, and growing on the surface of the transition metal sulfide layer to form a layered double hydroxide catalytic layer to obtain the self-supporting anode catalyst with a layered double hydroxide, transition metal oxide and foam nickel-iron three-layer structure. The invention can effectively solve the problems of weak binding force between the non-noble metal anode catalyst layer and the substrate and poor stability under high current density, thereby realizing oxygen evolution reaction with high activity, high stability and long service life in an alkaline or anion exchange membrane water electrolysis system.

Inventors

  • ZHANG QI
  • ZENG YAN
  • LI YIXING
  • MA XIAOYU
  • Liang tianfeng
  • LEI XIANZHANG
  • XU ZIQI
  • FANG MING
  • LIU XING
  • LI XIAO
  • FENG LIANG
  • QIU BIN
  • DING YU

Assignees

  • 成都市排水有限责任公司
  • 天府永兴实验室

Dates

Publication Date
20260512
Application Date
20260312

Claims (10)

  1. 1. The preparation method of the self-supporting anode catalyst is characterized by comprising the following steps of: step S1, providing and preprocessing a foam nickel-iron substrate; S2, immersing the pretreated foam nickel-iron substrate into a first precursor solution for standing reaction, growing in situ on the surface of the substrate to form a transition metal sulfide layer, and washing and drying to obtain an intermediate product; step S3, placing the intermediate product in a second precursor solution for hydrothermal reaction, and growing a layered double hydroxide catalytic layer on the surface of the transition metal sulfide layer to obtain a self-supporting anode catalyst with a layered double hydroxide, transition metal oxide and foam ferronickel three-layer structure; The first precursor solution comprises nickel salt, ferric salt and a sulfur source, and the second precursor solution comprises nickel salt, ferric salt, urea and ammonium fluoride.
  2. 2. The method for preparing the self-supporting anode catalyst according to claim 1, wherein in the step S1, the content ratio of nickel to iron in the foam nickel-iron substrate is 1:1, and the pretreatment specifically comprises the steps of placing the foam nickel-iron substrate in an acid solution for ultrasonic cleaning, removing a surface oxide layer, and then washing with water and ethanol in sequence and drying.
  3. 3. The method of preparing a self-supporting anode catalyst according to claim 2, wherein the acid solution is 1 mol/l hydrochloric acid solution, and the ultrasonic cleaning time is 25 minutes to 35 minutes.
  4. 4. The method for preparing a self-supported anode catalyst according to claim 1, wherein in the step S2, the first precursor solution is nickel chloride hexahydrate, ferric chloride nonahydrate, and the sulfur source is sodium thiosulfate pentahydrate, and the standing reaction is performed at normal temperature and pressure for 14 to 16 hours.
  5. 5. The method of preparing a self-supported anode catalyst according to claim 1, wherein in the step S3, the second precursor solution is nickel nitrate hexahydrate, the iron salt is ferric nitrate hexahydrate, and the hydrothermal reaction is performed at a temperature of 100 ℃ to 120 ℃ for 4 hours.
  6. 6. The method of preparing a self-supported anode catalyst according to any one of claims 1 to 5, wherein the transition metal sulfide layer formed in step S2 is converted into nickel iron oxide intercalation during a subsequent hydrothermal reaction.
  7. 7. The self-supporting anode catalyst is characterized by being prepared by adopting the preparation method of any one of claims 1-6, and the self-supporting anode catalyst has a self-supporting three-layer composite structure, and sequentially comprises a nickel-iron-based layered double hydroxide catalytic layer, a nickel-iron oxide intercalation layer and a foam nickel-iron substrate from outside to inside.
  8. 8. The self-supporting anode catalyst of claim 7, wherein the nickel iron-based layered double hydroxide catalytic layer has a nanosphere-like microtopography formed from the interpenetration of nanoplatelets.
  9. 9. Use of a self-supporting anode catalyst according to claim 7 or 8 in an electrolyzed water oxygen evolution reaction.
  10. 10. Use according to claim 9, in particular for anodic oxygen evolution reactions in alkaline or anion exchange membrane electrolyzed water systems.

Description

Preparation method of self-supporting anode catalyst, catalyst and application of catalyst Technical Field The invention relates to the technical field of electrolytic water oxygen evolution catalysts, in particular to a preparation method of a self-supporting anode catalyst, the catalyst and application thereof. Background The hydrogen production by water electrolysis is one of key technologies for realizing green hydrogen energy industrialization, wherein oxygen evolution reaction of an anode is a bottleneck for limiting the overall efficiency, and the core of the hydrogen production is a high-performance, low-cost and stable anode catalyst. At present, research and application are mainly focused on two types of materials, namely, a noble metal catalyst represented by ruthenium and iridium, which has excellent activity and stability, but high cost and scarcity limit large-scale industrial application, and a non-noble metal catalyst represented by nickel-iron-based layered double hydroxide, which has low cost and good activity, is paid attention to, and is considered as a potential alternative. However, existing non-noble metal catalysts, represented by nickel-iron-based layered double hydroxides, are typically grown directly on foam metal substrates, with the following obvious technical drawbacks: Firstly, the physical binding force between the catalytic layer and the substrate is weak, and the catalytic layer is easy to peel off and fall off from the substrate under the working condition of long time or high current density, so that the electrode structure is damaged and the activity is quickly attenuated. Secondly, the material system has limited conductivity, and the structure is unstable under the condition of high current density, so that the catalytic activity and long-term operation stability of the material system under the working condition of high current density are far from the requirements of industrial application. Disclosure of Invention In order to solve at least part of the technical problems in the related art, the invention provides a preparation method of a self-supporting anode catalyst, the catalyst and application thereof. The invention adopts low-cost foam ferronickel as a substrate, and adds the low-cost foam ferronickel between the low-cost foam ferronickel and NiFe-LDHIntercalation, enhancing the binding capacity between the catalytic layer and the substrate. The preparation process of the intermediate intercalation is carried out at normal temperature and normal pressure, which is beneficial to experimental amplification. In the present inventionThe intercalation improves the catalytic activity and the conductivity, has excellent performance under the condition of high current density, and can realize long-time and high-current stable test. In order to achieve the above purpose, the technical scheme adopted by the invention comprises the following steps: According to a first aspect of the present invention, there is provided a method of preparing a self-supporting anode catalyst comprising the steps of: step S1, providing and preprocessing a foam nickel-iron substrate; S2, immersing the pretreated foam nickel-iron substrate into a first precursor solution for standing reaction, growing in situ on the surface of the substrate to form a transition metal sulfide layer, and washing and drying to obtain an intermediate product; step S3, placing the intermediate product in a second precursor solution for hydrothermal reaction, and growing a layered double hydroxide catalytic layer on the surface of the transition metal sulfide layer to obtain a self-supporting anode catalyst with a layered double hydroxide, transition metal oxide and foam ferronickel three-layer structure; The first precursor solution comprises nickel salt, ferric salt and a sulfur source, and the second precursor solution comprises nickel salt, ferric salt, urea and ammonium fluoride. Optionally, in the step S1, the content ratio of nickel to iron in the foam ferronickel substrate is 1:1, and the pretreatment specifically comprises the steps of placing the foam ferronickel substrate in an acid solution for ultrasonic cleaning, removing a surface oxide layer, and then washing with water and ethanol in sequence and drying. Alternatively, the acid solution is 1 mole per liter of hydrochloric acid solution and the time for ultrasonic cleaning is 25 minutes to 35 minutes. Optionally, in the step S2, the nickel salt is nickel chloride hexahydrate, the ferric salt is ferric chloride nonahydrate, the sulfur source is sodium thiosulfate pentahydrate, and the standing reaction is performed at normal temperature and normal pressure for 14 to 16 hours. Optionally, in the step S3, in the second precursor solution, the nickel salt is nickel nitrate hexahydrate, the iron salt is ferric nitrate hexahydrate, and the hydrothermal reaction is performed at a temperature of 100 ℃ to 120 ℃ for 4 hours. Optionally, the transition metal su