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CN-121988394-A - Nanometer island limited iron mononuclear site catalyst and synthesis method and application thereof

CN121988394ACN 121988394 ACN121988394 ACN 121988394ACN-121988394-A

Abstract

The invention discloses a nano island limited iron mononuclear site catalyst, a synthesis method and application thereof, relating to the technical field of water pollution control and resource recovery, wherein the catalyst takes spheroid C-Fe 0 as a nano island limited carrier, urea is introduced as a nitrogen source in the calcining process to coordinate with Fe atoms in C-Fe 0 , so that a FeN 4 mononuclear site is formed, and a space synergistic effect is formed with the nano island limited domain carrier. The preparation method comprises the steps of dissolving anhydrous sodium acetate in green tea extract, adding ferric nitrate nonahydrate solution, magnetically stirring, centrifuging, washing, freeze-drying after the reaction is completed to obtain an iron precursor, mixing the iron precursor with urea, and roasting in an inert gas environment to obtain the nano island limited domain iron mononuclear site catalyst, which is marked as C-Fe 0 @FeN 4 . The catalyst can enhance the coactivation capability of PAA and 2,6-DCP at the interface of C-Fe 0 @FeN 4 , induce the 2,6-DCP to generate high-efficiency oxidative polymerization reaction, and realize the synchronous emission reduction and carbon resource recovery of the 2, 6-DCP.

Inventors

  • LU JINFENG
  • QI WENLI
  • LI HENG

Assignees

  • 南开大学

Dates

Publication Date
20260508
Application Date
20251204

Claims (7)

  1. 1. A nano island limited domain iron mononuclear site catalyst is characterized in that spherical C-Fe 0 is used as a nano island limited domain carrier, urea is introduced as a nitrogen source in a calcining process to coordinate with Fe atoms in C-Fe 0 , so that a FeN 4 mononuclear site is formed, and a space synergistic effect is formed with the nano island limited domain carrier.
  2. 2. A method for preparing the nano island limited domain iron mononuclear site catalyst as claimed in claim 1, which is characterized by comprising the following steps: s1, adding green tea into deionized water, heating in a water bath, cooling to room temperature, and filtering to obtain green tea extract; S2, dissolving anhydrous sodium acetate in the green tea extract in the step S1, adding ferric nitrate nonahydrate solution, magnetically stirring, centrifuging, respectively washing the obtained precipitate with ethanol and water for three times, and freeze-drying to obtain an iron precursor; And S3, mixing the iron precursor obtained in the step S2 with urea, and roasting in an inert gas environment to obtain the nano island limited domain iron mononuclear site catalyst which is marked as C-Fe 0 @FeN 4 .
  3. 3. The preparation method of the green tea according to claim 2, wherein the ratio of the green tea mass to the deionized water volume in the step S1 is 20-30 g:400-600 mL, the water bath heating temperature is 70-90 ℃, and the water bath time is 50-70 min.
  4. 4. The preparation method according to claim 2, wherein the mass ratio of anhydrous sodium acetate to green tea in the step S2 is 5:3; The concentration of the ferric nitrate nonahydrate solution is 0.15M, and the volume ratio of the ferric nitrate nonahydrate solution to the deionized water in the step S1 is 6:5; the speed of the magnetic stirring is 200 rpm, and the time is 1h; The speed of centrifugation was 8000 rpm and the time was 5 min.
  5. 5. The method according to claim 2, wherein the mass ratio of the iron precursor to urea in step S3 is 1:10, and the baking temperature is 800 ℃ for 2 hours.
  6. 6. The application of the nano island-domain iron mononuclear site catalyst according to claim 1 or the nano island-domain iron mononuclear site catalyst prepared by the method according to any one of claims 2-5 in the halophenol oxidation polymerization treatment is characterized in that the nano island-domain iron mononuclear site catalyst and the peroxyacetic acid are added into a water body containing the halophenol together, and the stirring reaction is carried out under the light-shielding condition at 29-31 ℃, the stirring speed is 250rpm, and the time is 30 min.
  7. 7. The use according to claim 6, wherein the halogenated phenol is 2, 6-dichlorophenol.

Description

Nanometer island limited iron mononuclear site catalyst and synthesis method and application thereof Technical Field The invention relates to the technical field of water pollution control and resource recovery, in particular to a nano island limited domain iron mononuclear site catalyst and a synthesis method and application thereof. Background Halogenated phenols, which are typical endocrine disruptors, mutagens and carcinogens, are long-standing in industrial wastewater because of their chemical inertness, hydrophobicity and bioaccumulation, and pose serious potential threats to the ecological environment and human health. The traditional in-situ chemical oxidation technology (ISCO) aims at mineralizing the emerging pollutants in the water body through hydroxyl radicals, but still has the problems that 1. The consumption of the oxidant is large, the economy is poor, multiple chemical bonds (such as C-C, C-O, C-X bonds) of the organic pollutants are required to be destroyed in the mineralization process, a large amount of oxidant is required to be input, the molar ratio of the oxidant to the pollutants is generally up to 20:1-1000:1, the treatment cost is high, 2. The carbon resource waste and the carbon emission are remarkable, namely, the carbon element in the organic pollutants is completely oxidized into CO 2 to be discharged, the carbon resource recovery cannot be realized, and the carbon recycling economy concept is contrary to the carbon recycling economy concept. And 3, the risk of toxic byproducts is high, the high-oxidability free radicals are easy to react with impurities (such as Cl - and NOM) in the water body to generate halogenated disinfection byproducts (such as trichloromethane and nitrosamine) or toxic intermediates (such as p-benzoquinone), and the water body after treatment has potential ecological toxicity and needs to be additionally provided with an advanced treatment unit. Therefore, developing a novel catalytic system capable of directionally realizing the oxidative polymerization of halogenated phenols and simultaneously achieving detoxification and recycling is a technical problem to be solved in the field. Disclosure of Invention Aiming at the problems, the invention provides a nano island-limited iron mononuclear site catalyst, a synthesis method and application thereof, wherein the catalyst takes C-Fe 0 as a nano island-limited carrier, and enhances the coactivation capability of peracetic acid (PAA) and 2, 6-dichlorophenol (2, 6-DCP) at a C-Fe 0@FeN4 interface by accurately regulating and controlling the coordination environment and spatial distribution of FeN 4, and induces the 2,6-DCP to generate efficient oxidative polymerization reaction, thereby realizing synchronous emission reduction of the 2,6-DCP and carbon resource recovery. In order to achieve the above purpose, the invention firstly provides a nano island limited domain iron mononuclear site catalyst, which takes spheroid C-Fe 0 as a nano island limited domain carrier, urea is introduced as a nitrogen source in the calcining process to coordinate with Fe atoms in C-Fe 0, so as to form FeN 4 mononuclear sites, and the FeN 4 mononuclear sites and the nano island limited domain carrier form a space synergistic effect. Secondly, the invention provides a preparation method of the nano island limited domain iron mononuclear site catalyst, which specifically comprises the following steps: S1, adding green tea into deionized water, heating in a water bath, cooling to room temperature, and filtering to obtain green tea extract. S2, dissolving anhydrous sodium acetate in the green tea extract in the step S1, adding ferric nitrate nonahydrate solution, magnetically stirring, centrifuging, washing the obtained precipitate with ethanol and water for three times respectively, and freeze-drying to obtain an iron precursor. And S3, mixing the iron precursor obtained in the step S2 with urea, and roasting in an inert gas environment to obtain the nano island limited domain iron mononuclear site catalyst which is marked as C-Fe 0@FeN4. Preferably, in the step S1, the ratio of the mass of the green tea to the volume of the deionized water is 20-30 g:400-600 mL, the heating temperature of the water bath is 70-90 ℃, and the water bath time is 50-70 min. Preferably, in the step S2, the mass ratio of the anhydrous sodium acetate to the green tea is 5:3, the concentration of the ferric nitrate nonahydrate solution is 0.15M, the mass ratio of the ferric nitrate nonahydrate to the green tea is 36.36:30, the magnetic stirring speed is 200 rpm, the time is 1h, the centrifugation speed is 8000 rpm, and the time is 5 min. Preferably, in the step S3, the mass ratio of the iron precursor to the urea is 1:10, and the roasting temperature is 800 ℃ and the time is 2h. Finally, the application also provides application of the nano island limited domain iron mononuclear site catalyst in halophenol oxidation polymerization treatment, which comprises