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CN-120818843-B - Preparation method, product and application of catalyst

CN120818843BCN 120818843 BCN120818843 BCN 120818843BCN-120818843-B

Abstract

The invention relates to the field of electrolytic water anode oxygen precipitation catalysts, in particular to a preparation method, a product and application of a catalyst. The preparation method of the catalyst comprises the following steps of 1, mixing fly ash and NaHCO 3 uniformly, calcining to obtain activated fly ash, 2, adding a Co source, a Fe source, ammonium chloride and ammonia water into water, mixing uniformly, adding the activated fly ash, mixing uniformly, performing hydrothermal reaction to obtain FA-CoFeSi, and 3, adding the FA-CoFeSi and a nickel source into water, mixing uniformly, and adding a reducing agent to react to obtain the catalyst. The catalyst prepared by the method of the invention keeps the current density at 83% after continuous operation for 48 hours under constant voltage. The invention provides a low-cost preparation method for the electrolyzed water oxygen evolution catalyst, and realizes the high-value utilization of the fly ash.

Inventors

  • YANG LONG
  • ZHANG YAJIE
  • ZHANG WENZE
  • ZHANG YINGYING
  • JI GUOJUN
  • PEI HONGYU

Assignees

  • 内蒙古工业大学

Dates

Publication Date
20260508
Application Date
20250917

Claims (7)

  1. 1. The application of the catalyst in the electrolytic water oxygen evolution is characterized in that the preparation method of the catalyst comprises the following steps: Step 1, uniformly mixing fly ash and NaHCO 3 , and calcining to obtain activated fly ash; step 2, adding a Co source, a Fe source, ammonium chloride and ammonia water into water, uniformly mixing, adding the activated fly ash, uniformly mixing, and performing hydrothermal reaction to obtain FA-CoFeSi; And step 3, adding the FA-CoFeSi and a nickel source into water, uniformly mixing, and adding a reducing agent for reaction to obtain the catalyst.
  2. 2. The use according to claim 1, wherein in step 1, the mass ratio of the fly ash to the NaHCO 3 is 1:0.1-1.2.
  3. 3. The use according to claim 1, wherein in step 1, the calcination temperature is 700 ℃ to 900 ℃ for 1 to 3 hours.
  4. 4. The use according to claim 1, wherein in step 2, the Co source is cobalt chloride, the Fe source is ferrous chloride, the molar ratio of the Co source, fe source, ammonium chloride is 1:1:5, the amount ratio of the Co source to the aqueous ammonia is 1 mmol:4 mL, the amount ratio of the Co source to the water is 1 mmol:40 mL, and the amount ratio of the Co source to the activated fly ash is 1 mmol:60 mg.
  5. 5. The use according to claim 1, wherein in step 2 the hydrothermal reaction is carried out at a temperature of 180 ℃ for a time of 24 h.
  6. 6. The application of claim 1, wherein in the step 3, the nickel source is nickel chloride, the mass ratio of the FA-CoFeSi to the nickel source is 1:1-1.1, the reducing agent is NaBH 4 , and the mass ratio of the FA-CoFeSi to the reducing agent is 1:5-6.
  7. 7. The use according to claim 1, wherein in step 3, the reaction time is 4h.

Description

Preparation method, product and application of catalyst Technical Field The invention relates to the field of electrolytic water anode oxygen precipitation catalysts, in particular to a preparation method, a product and application of a catalyst. Background The rapid development of human society has led to a significant increase in energy consumption, with over 60% of the energy being currently derived from the combustion of fossil fuels worldwide. The combustion of fossil fuels can emit a great amount of toxic and harmful gases such as carbon oxides and sulfides, which cause a series of problems such as environmental pollution and global warming. Therefore, the development of environmentally friendly energy sources is critical to solve the problems of resource exhaustion and environmental pollution. The hydrogen has high energy density, and the combustion products are pollution-free and convenient to store. At present, hydrogen can be produced through the methods of steam methane conversion, natural gas reforming, petroleum cracking and the like, and certain environmental pollution can be brought. Electrolytic water hydrogen production is considered as a promising approach to solve the energy and environmental problems associated with fossil fuel consumption. The electrolytic water reaction consists of two half reactions, namely an Oxygen Evolution Reaction (OER) of an anode and a Hydrogen Evolution Reaction (HER) of a cathode, wherein the OER reaction of the anode is a four-electron transfer reaction, and the kinetics process is slow, so that the electrolytic water reaction becomes a main bottleneck for improving the electrocatalytic water decomposition efficiency. At present, most of typical electrolytic water oxygen evolution catalysts are noble metal catalysts such as iridium dioxide (IrO 2) and ruthenium dioxide (RuO 2), and the high price limits the large-scale industrial production of the catalysts. The current research direction tends to prepare low-cost and environment-friendly electrolytic water oxygen evolution catalysts. Fly ash is a solid waste produced by coal-fired enterprises such as thermal power plants, and has wide sources and low price. The use of the fly ash as the carrier can greatly reduce the preparation cost of the catalyst, is beneficial to large-scale production and application, realizes the recycling of solid waste, reduces the pollution of the fly ash to the environment and occupied land resources, and accords with the concept of sustainable development. The fly ash faces remarkable challenges in the recycling process, and is mainly characterized in that silicon dioxide (SiO 2) in the fly ash exists in a crystal state, and the chemical activity of the fly ash is greatly limited due to the extremely high Si-O chemical bond energy and the high chemical stability, so that the reaction difficulty is increased. It is necessary to research a catalyst with low cost, high catalytic activity and good stability. Disclosure of Invention Based on the above, the invention provides a preparation method, a product and application of the catalyst. In order to achieve the above object, the present invention provides the following solutions: the first aspect of the invention provides a method for preparing a catalyst, comprising the following steps: Step 1, uniformly mixing fly ash and NaHCO 3, and calcining to obtain activated fly ash; step 2, adding a Co source, a Fe source, ammonium chloride and ammonia water into water, uniformly mixing, adding the activated fly ash, uniformly mixing, and performing hydrothermal reaction to obtain FA-CoFeSi; and 3, adding the FA-CoFeSi and a nickel source into water, uniformly mixing, and adding a reducing agent for reaction to obtain the catalyst (Ni@FA-CoFeSi). The second aspect of the invention provides a catalyst prepared according to the preparation method. In a third aspect, the invention provides the use of the catalyst described above in the oxygen evolution of electrolyzed water. The invention discloses the following technical effects: The invention provides a preparation method of a solid waste fly ash electrolytic water oxygen precipitation catalyst, which converts crystalline SiO 2 into active calcium silicate Ca 2SiO4 through NaHCO 3 roasting, simultaneously releases CO 2、H2 O gas to etch out a porous structure, and increases the specific surface area of a carrier. The one-step hydrothermal method can be carried out at a relatively low temperature (180 ℃) and under autogenous pressure, so that the directional conversion of silicon oxide in the fly ash and the metal ion exchange are realized. The coal-fired solid waste fly ash is used as a silicon source, and the cheap transition metal salt (CoCl 2)、(FeCl2) is combined to prepare the fly ash-based cobalt iron silicate as a catalyst carrier, so that the production cost is greatly reduced. The supported nickel catalyst (Ni@FA-CoFeSi) prepared by the reduction method has an overpotential as low as 1