WO2023024031A1 - 金属原子负载型碳纳米纤维催化剂及其制备方法和应用 - Google Patents

金属原子负载型碳纳米纤维催化剂及其制备方法和应用 Download PDF

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WO2023024031A1
WO2023024031A1 PCT/CN2021/114813 CN2021114813W WO2023024031A1 WO 2023024031 A1 WO2023024031 A1 WO 2023024031A1 CN 2021114813 W CN2021114813 W CN 2021114813W WO 2023024031 A1 WO2023024031 A1 WO 2023024031A1
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carbon nanofiber
supported carbon
product
metal atom
zif
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PCT/CN2021/114813
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French (fr)
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孙轶斐
刘兴双
朱秉钧
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北京航空航天大学
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Priority to PCT/CN2021/114813 priority patent/WO2023024031A1/zh
Publication of WO2023024031A1 publication Critical patent/WO2023024031A1/zh

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • B01J35/58—Fabrics or filaments
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8659—Removing halogens or halogen compounds
    • B01D53/8662—Organic halogen compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8668—Removing organic compounds not provided for in B01D53/8603 - B01D53/8665
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/18—Carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/74—Iron group metals
    • B01J23/755—Nickel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/391—Physical properties of the active metal ingredient
    • B01J35/394—Metal dispersion value, e.g. percentage or fraction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/61—Surface area
    • B01J35/615—100-500 m2/g
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/61—Surface area
    • B01J35/617—500-1000 m2/g
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B01J37/082—Decomposition and pyrolysis
    • B01J37/084—Decomposition of carbon-containing compounds into carbon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/34—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation
    • B01J37/341—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of electric or magnetic fields, wave energy or particle radiation
    • B01J37/342—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of electric or magnetic fields, wave energy or particle radiation of electric, magnetic or electromagnetic fields, e.g. for magnetic separation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/20—Halogens or halogen compounds
    • B01D2257/206—Organic halogen compounds
    • B01D2257/2064—Chlorine
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/70—Organic compounds not provided for in groups B01D2257/00 - B01D2257/602
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • B01D2258/0291—Flue gases from waste incineration plants

Definitions

  • the invention relates to the technical field of catalyst preparation, in particular to a metal atom-supported carbon nanofiber catalyst and its preparation method and application.
  • Chlorobenzenes (CBzs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDFs) and polychlorinated naphthalenes ( PCNs) and other unintentionally produced persistent organic pollutants (UPOPs) are mainly produced in the iron and steel production process, such as the process of producing steel through iron ore sintering, which not only produces dust, SO2, NOx and other pollutants, but also The generation of UPOPs has serious environmental pollution, and does not meet the emission requirements for UPOPs in the "Ironmaking Industry Air Pollutant Emission Standard” and "Steelmaking Industry Air Pollutant Emission Standard” (for example, the general requirements for the emission of dioxin-like pollutants The emission limit is limited to 0.5ng-TEQ/m3).
  • UPOPs are mainly degraded by incineration combined with activated carbon adsorption, that is, the pollutants containing UPOPs are first incinerated, and then activated carbon is used to absorb the tail gas generated during the incineration process.
  • the degradation process requires high-temperature incineration, which consumes a lot of energy. Strict requirements, high equipment maintenance costs, and high costs.
  • the exhaust gas is adsorbed by activated carbon, and the residual UPOPs in the exhaust gas will be adsorbed in the activated carbon.
  • the activated carbon adsorbed with UPOPs is difficult to treat and easily leads to secondary pollution.
  • the degradation efficiency of UPOPs in this treatment process also needs to be further improved.
  • the invention provides a metal atom-supported carbon nanofiber catalyst and its preparation method and application.
  • the catalyst has good catalytic degradation performance for UPOPs, and can avoid the large energy consumption, high cost, and easy production of UPOPs in the existing process of degrading UPOPs. Defects such as secondary pollution and low degradation efficiency.
  • One aspect of the present invention provides a method for preparing a metal atom-supported carbon nanofiber catalyst, comprising the following steps: (1) mixing methanol, the first metal salt, the second metal salt and dimethylimidazole to obtain the first Mixed system; the first metal salt includes a soluble salt of zinc, and the second metal salt includes a soluble salt of copper and/or a soluble salt of nickel; the mixed system is allowed to stand still to produce a precipitate; the precipitate is collected and dried to obtain a loaded There are ZIF-8 products of copper and/or nickel; (2) ZIF-8 products are added to a solution containing a nitrogen-containing polymer to obtain a second mixed system; the second mixed system is electrospun to make nanofibers product; (3) pyrolyzing the nanofiber product at a temperature not lower than 950° C. to obtain a metal atom-supported carbon nanofiber catalyst.
  • step (1) the molar ratio of the soluble salt of zinc to dimethylimidazole is 1-2.5:20.
  • the drying is carried out under vacuum condition, and the drying temperature is 50-80°C.
  • the consumption of the soluble salt of copper satisfies: make the mass content of copper in the ZIF-8 product be 0 ⁇ 0.7%; And/or, the consumption of the soluble salt of nickel satisfies: make ZIF-8 product The mass content of nickel is 0-1.4%.
  • the particle size of the ZIF-8 product used in the control step (2) is 60-100 nm; and/or, the nitrogen-containing polymer includes polyacrylonitrile.
  • the mass ratio of ZIF-8 product to nitrogen-containing polymer is 0.1 ⁇ 2:1; and/or, the solution containing nitrogen-containing polymer is nitrogen-containing polymer
  • the polymer is prepared by dissolving in an organic solvent, wherein the mass ratio of the organic solvent to the nitrogen-containing polymer is 5:1-12:1.
  • the conditions of the electrospinning treatment are: the spinning voltage is 20-25 kV, and the inner diameter of the spinning port is 0.6 mm.
  • the pyrolysis treatment is performed in an inert atmosphere, and/or the temperature of the pyrolysis treatment is 950° C. to 1100° C., and/or the time of the pyrolysis treatment is 0.5 to 3 hours.
  • the second aspect of the present invention provides a metal atom-supported carbon nanofiber catalyst, which is prepared by the above-mentioned preparation method of the metal atom-supported carbon nanofiber catalyst.
  • the third aspect of the present invention provides an application of a metal atom-supported carbon nanofiber catalyst in degrading unintentionally produced quasi-POPs.
  • ZIF-8 product loaded with copper and/or nickel is synthesized in situ.
  • the ZIF-8 product has the characteristics of high specific surface area and easy modification of pore structure, and then the ZIF-8 product is combined with The nitrogen-containing polymer mixture is electrospun to produce a nanofiber product, and the nanofiber product is subjected to pyrolysis treatment at a temperature not lower than 950°C to obtain a metal atom-supported carbon nanofiber catalyst.
  • Fig. 1 is the scanning electron micrograph of metal atom supported carbon nanofiber catalyst in one embodiment of the present invention
  • Fig. 2 is a high-resolution transmission electron microscope image of a metal atom-supported carbon nanofiber catalyst in an embodiment of the present invention.
  • One aspect of the present invention provides a method for preparing a metal atom-supported carbon nanofiber catalyst, comprising the following steps: (1) mixing methanol, the first metal salt, the second metal salt and dimethylimidazole to obtain the first Mixed system; the first metal salt includes a soluble salt of zinc, and the second metal salt includes a soluble salt of copper and/or a soluble salt of nickel; the mixed system is allowed to stand still to produce a precipitate; the precipitate is collected and dried to obtain a loaded There are ZIF-8 products of copper and/or nickel; (2) ZIF-8 products are added to a solution containing a nitrogen-containing polymer to obtain a second mixed system; the second mixed system is electrospun to make nanofibers product; (3) pyrolyzing the nanofiber product at a temperature not lower than 950° C. to obtain a metal atom-supported carbon nanofiber catalyst.
  • step (1) in the first mixed system, soluble zinc salts are dissolved in methanol to generate Zn 2+ , and Zn 2+ coordinates with dimethylimidazole to self-assemble into a metal-organic framework, that is, zeolite imidazole Ester backbone material (ZIF-8).
  • ZIF-8 zeolite imidazole Ester backbone material
  • the formation of ZIF-8 includes two processes of nucleation and crystal growth. First, dimethylimidazole deprotonates and coordinates with Zn 2+ to form a crystal nucleus, and then the crystal nucleus grows rapidly to form ZIF-8 nanocrystalline particles, namely ZIF -8. In general, adding excess dimethylimidazole is more conducive to the rapid formation of ZIF-8 crystals.
  • the copper comes from a soluble salt of copper
  • the nickel comes from a soluble salt of nickel
  • the above-mentioned second metal salt can be a soluble salt of copper or a soluble salt of nickel
  • soluble salts of copper and soluble salts of nickel are included at the same time.
  • the soluble salt of copper includes, for example, copper nitrate
  • the soluble salt of nickel includes, for example, nickel nitrate.
  • the above-mentioned soluble salt of zinc may include zinc nitrate.
  • the order of adding methanol, the first metal salt, the second metal salt and dimethylimidazole is not limited.
  • the first metal salt, the second metal salt, and methanol can be mixed to form the first mixed solution, methanol is added to dimethylimidazole to form a methanol solution containing dimethylimidazole, and then the metal salt mixed solution and dimethylimidazole are mixed.
  • the methanol solution of imidazole is mixed to obtain the first mixed system.
  • methanol is preferably anhydrous methanol, and methanol is used as a dispersion medium, which can promote the dispersion of metal salts and dimethylimidazole.
  • the process of collecting the precipitate includes: centrifuging the first mixed system that produces the precipitate, wherein the centrifugation can be performed by conventional means in the art, and after the centrifugation, the solid and the liquid are separated, and the solid is retained. The resulting precipitate was collected.
  • the centrifuge is processed in a centrifuge.
  • the centrifuge is centrifuged under the condition of 13000g, and the centrifuge time is 5min.
  • the first mixing system can be placed in the centrifuge Run at 13000g for 5 minutes, where g is the acceleration due to gravity.
  • the precipitate is washed with an organic solvent, and then dried to obtain a ZIF-8 product loaded with copper and/or nickel.
  • the washing treatment can be carried out by conventional means in the art, wherein the organic solvent includes methanol.
  • the molar ratio of the soluble zinc salt to dimethylimidazole is 1-2.5:20, such as 1:20, 1.5:20, 2:20, 2.5:20 or any of them
  • the order of adding the raw materials is not limited, as long as the soluble salt of zinc and dimethylimidazole are controlled at the above molar ratio.
  • the process of mixing methanol, the first metal salt, the second metal salt and dimethylimidazole includes: mixing the first metal salt, the second metal salt and part of methanol to obtain the first mixed solution; dissolving dimethylimidazole in the remaining methanol to obtain a second mixed solution (that is, a methanol solution containing dimethylimidazole); mixing the first mixed solution and the second mixed solution to obtain a first mixed system.
  • the first mixed solution includes a soluble salt of zinc and a soluble salt of nickel, the concentration of the soluble salt of zinc in the first mixed solution is 0.04 ⁇ 0.1mol/L, and the concentration of the soluble salt of nickel in the first mixed solution is 0.045 ⁇ 0.06mol/L, or, the soluble salt of zinc and the soluble salt of copper are included in the first mixed solution, the concentration of the soluble salt of zinc in the first mixed solution is 0.04 ⁇ 0.1mol/L, and copper is included in the first mixed solution The concentration of the soluble salt is 0.0025 ⁇ 0.0125mol/L.
  • the process of mixing the first metal salt, the second metal salt and part of methanol may include: mixing the methanol solution of the first metal salt and the methanol solution of the second metal salt to obtain a first mixed solution.
  • drying is carried out under vacuum conditions, and the drying temperature is 50-80°C, such as 50°C, 60°C, 70°C, 80°C or any combination thereof.
  • the methanol was volatilized to obtain a solid mixture, namely the ZIF-8 product loaded with copper and/or nickel.
  • the mass ratio of copper and/or nickel loading in the ZIF-8 product is controlled.
  • the ZIF-8 product loaded with copper and/or nickel will not affect the pore structure of ZIF-8, and nickel and copper are uniformly dispersed on the surface and inside of ZIF-8.
  • the amount of the soluble salt of copper meets: the mass content of copper in the ZIF-8 product is 0-0.7%, such as 0, 0.1%, 0.2%, 0.5%, 0.7% or any two thereof range of composition.
  • the amount of the soluble salt of nickel satisfies: make the mass content of nickel in the ZIF-8 product be 0 ⁇ 1.4%, for example 0, 0.5%, 1%, 1.4% or the scope of any two composition wherein .
  • the particle size of the ZIF-8 product used in the control step (2) is 60 to 100 nm.
  • the specific process of the particle diameter of the ZIF-8 product used in the control step (2) comprises: the ZIF-8 product that step (1) obtains is carried out
  • the particle size of the product obtained after grinding is preferably 60-100nm, such as 60nm, 80nm, 100nm or any combination thereof.
  • nitrogen-containing polymers are polymers containing nitrogen groups, such as cyano groups (-CN), amino groups (-NH 2 ), imino groups (-NH-), amido groups (-NH-CO -) and other polymers, such as polyacrylonitrile, polyethyleneimine, etc.
  • the nitrogen-containing polymer includes polyacrylonitrile.
  • the mass ratio of ZIF-8 product to nitrogen-containing polymer is 0.1-2:1, such as 0.1:1, 0.5:1, 1:1, 1.5:1, 2 : 1 or a range consisting of any two of them.
  • the nitrogen-containing polymer is dissolved in an organic solvent to obtain a solution containing the nitrogen-containing polymer, wherein the mass ratio of the organic solvent to the nitrogen-containing polymer is 5:1 to 12:1, such as 5: 1, 7:1, 9:1, 11:1, 12:1 or any combination thereof, in a preferred embodiment, the organic solvent includes N,N-dimethylformamide, generally It is a colorless and transparent liquid, and the nitrogen-containing polymer meeting the mass ratio is added into N,N-dimethylformamide and mixed uniformly, for example, it can be heated and mixed uniformly at a heating temperature of 60°C.
  • step (2) the solution containing the nitrogen-containing polymer and the ZIF-8 product are uniformly mixed to obtain the second mixed system, and the technical scheme of uniform mixing well known to those skilled in the art can be adopted, for example, at a temperature of 60° C. Mix the solution containing the nitrogen-containing polymer and the ZIF-8 product uniformly under certain conditions to obtain the second mixed system.
  • the electrospinning process is carried out using conventional electrospinning equipment in the art, and the second mixed system is electrospun to obtain a nanofiber-like nanofiber product.
  • the conditions of the electrospinning process It is: the spinning voltage is 20-25kV, and the inner diameter of the spinning port is 0.6mm.
  • the spinning speed is 0.6-0.8mL/h, the particle size of the prepared nanofiber product is 100-400nm, and the distribution of ZIF-8 in the nanofiber product is further dispersed by electrospinning.
  • step (3) the nanofiber product is subjected to pyrolysis treatment at not lower than 950° C. to obtain a metal atom-supported carbon nanofiber catalyst.
  • the pyrolysis treatment is carried out in an inert atmosphere or vacuum under, preferably under an inert atmosphere, such as a nitrogen atmosphere.
  • the pyrolysis treatment is constant temperature pyrolysis, and the temperature of the pyrolysis treatment is not lower than 950°C, preferably 950-1100°C, such as 950°C, 980°C, 1000°C, 1100°C or any of them
  • the range of the composition of the two; the time of pyrolysis treatment is 0.5 ⁇ 3h, such as 0.5h, 1h, 2h, 3h or the scope of any two composition thereof, the time of pyrolysis treatment is preferably 2h, for example, the time of pyrolysis treatment can be Operate in an electric heating reactor, put the nanofiber product into the electric heating reactor, raise the temperature to 1000°C at a heating rate of 5°C/min, keep it warm for 2h for constant temperature pyrolysis treatment.
  • the nanofiber product undergoes a high-temperature carbonization process, and the ZIF-8 structure in the nanofiber product gradually decomposes and carbonizes to form carbon nanofibers, which have a large number of nano-hollow bubbles, that is, have a porous structure, in which the metal Zn gradually volatilizes, and As the inert gas is exhausted, the groups containing nitrogen decompose to form nitrogen doped into carbon nanofibers, nickel salts and copper salts decompose into nickel atoms, and copper atoms are supported on carbon nanofibers to form nickel and/or copper-carbon- Nitrogen structure.
  • the pyrolysis-treated product After the pyrolysis treatment in step (3), in the specific implementation of the present invention, it is preferable to grind the pyrolysis-treated product after cooling to obtain a metal atom-supported carbon nanofiber catalyst.
  • the particle size of the metal atom-supported carbon nanofiber catalyst is preferably 200 to 300 nm.
  • the second aspect of the present invention provides a metal atom-supported carbon nanofiber catalyst, which is prepared by the above-mentioned preparation method of the metal atom-supported carbon nanofiber catalyst.
  • the metal atom-supported carbon nanofiber catalyst contains a large number of nano-hollow bubbles, has the advantages of large specific surface area, low density, and good dispersibility, and the specific specific surface area can reach 500-700 square meters per gram.
  • the nanofiber catalyst has a porous carbon nanofiber structure, which can improve the adsorption capacity of gases.
  • the metal atom-supported carbon nanofiber catalyst contains transition metals, which not only increases the active metal sites, but also has high dispersion, which greatly improves the The reactivity of the catalyst.
  • the third aspect of the present invention provides an application of a metal atom-supported carbon nanofiber catalyst in degrading unintentionally produced quasi-persistent organic pollutants (UPOPs).
  • UPOPs quasi-persistent organic pollutants
  • the catalyst provided by the invention can be used for the purification treatment of flue gas containing UPOPs, not only has an excellent purification effect on flue gas with high UPOPs concentration, but also can achieve good purification effect on flue gas with low UPOPs concentration (0.1ng-TEQ/m 3 ). purification effect.
  • the flue gas may include at least one of domestic waste incineration flue gas, recycled copper smelting flue gas, iron ore sintering flue gas, and the like.
  • UPOPs include at least one of polychlorinated biphenyls, chlorobenzenes, and dioxins
  • the metal atom-supported carbon nanofiber catalyst of the present invention has good degradation of polychlorinated biphenyls, chlorobenzenes, and dioxins Effect, the degradation efficiency can be as high as 97.58%.
  • the purified flue gas is obtained, and gas chromatography-mass spectrometry (GC-MS) is used for quantitative analysis of chlorobenzene
  • GC-MS gas chromatography-mass spectrometry
  • HRGC-HRMS high-resolution gas chromatography-high-resolution mass spectrometry
  • the conditions of the degradation process are mild.
  • the catalytic degradation temperature is 150-350°C, such as 150°C, 200°C, 250°C, 300°C, 350°C or In the range of any combination of the two, in the specific implementation process of the present invention, the above degradation process is carried out under an inert atmosphere, and the inert atmosphere includes, for example, a nitrogen atmosphere.
  • the catalyst of 0.1g is filled in the tubular reactor to form a catalytic layer, and the flue gas containing UPOPs is passed into the tubular reactor, and the flue gas containing UPOPs is carried out when passing through the catalytic layer.
  • Purification treatment wherein the diameter of the tubular reactor is 1 cm, and the height of the catalytic layer is 2 cm.
  • a single gram of catalyst can degrade 100 micrograms of dioxin pollutants, where g is gram.
  • the present invention will be further described below by specific examples and comparative examples.
  • the reagents, materials and instruments used below are conventional reagents, conventional materials and conventional instruments, all of which are commercially available, and the involved reagents and materials can also be synthesized by conventional synthesis methods.
  • g in the present invention is a unit of weight.
  • Zinc nitrate, nickel nitrate, copper nitrate, methanol are mixed uniformly to form the first mixed solution of 100mL; in this first mixed solution, the concentration of zinc nitrate is 4mmoL, the concentration of nickel nitrate is 6mmoL, the concentration of copper nitrate 0.5mmoL;
  • the centrifuge is centrifuged under the condition of 13000g (wherein g is the acceleration of gravity), the centrifugation time is 5min, the drying condition is to carry out under vacuum conditions, and the drying temperature is 60°C;
  • Electrospinning the second mixed system to obtain a nanofiber product wherein the conditions for electrospinning are: the spinning voltage is 20kV, and the inner diameter of the spinning port is 0.6mm;
  • the nanofiber product is subjected to pyrolysis treatment to obtain a metal atom-supported carbon nanofiber catalyst, wherein the conditions of the pyrolysis treatment are: carried out under a nitrogen atmosphere, the temperature is raised to 1000° C. at a heating rate of 5° C./min, and the temperature is constant. 2h.
  • the catalyst in Example 1 is used to treat the iron ore sintering flue gas at 350°C, wherein the mass of the catalyst is 0.1g, the volume of the iron ore sintering flue gas is 2m 3 , and the iron ore sintering flue gas The amount of dioxin is 1.2ng-TEQ/m 3 . According to the analysis results, it can be seen that the catalyst provided by the invention can catalyze and degrade chlorobenzene, polychlorinated biphenyls, and dioxin-like organic pollutants in flue gas. The rates are 99.95%, 99.73%, and 99.92%, respectively.
  • step (3) the ZIF-8 product of 0.5g is replaced with the ZIF-8 product of 0.8g, in step (4), the The spinning voltage of 20kV is replaced by the spinning pressure of 21kV, and other conditions remain unchanged.
  • the catalyst in Example 2 was used to treat the recycled copper smelting flue gas at 300°C, wherein the mass of the catalyst was 0.1 g, the volume of the recycled copper smelting flue gas was 1 m 3 , and the dioxin in the recycled copper smelting flue gas The amount of dioxin is 0.5ng-TEQ/m 3 . According to the analysis results, it can be known that the catalyst provided by the present invention can catalyze and degrade chlorobenzene, polychlorinated biphenyls, and dioxin-like organic pollutants in flue gas, and the degradation rates are respectively 99.02%, 97.58%, 98.76%.
  • step (1) nickel nitrate is not added in the step (1), and the concentration of zinc nitrate is 4mmoL, and the concentration of copper nitrate is 0.5mmoL to replace the concentration of zinc nitrate as 10mmoL, and the concentration of copper nitrate is 1.25mmoL
  • step (2) adding 0.5 g of polyacrylonitrile to 4.5 g of N,N-dimethylformamide is replaced by adding 0.6 g of polyacrylonitrile to 5.4 g of N,N-dimethylformamide
  • step (3) 0.5 g of the ZIF-8 product was replaced by 1.2 g of the ZIF-8 product, and other conditions remained unchanged.
  • the catalyst in Example 3 was used to treat the flue gas of domestic waste incineration under the condition of 300°C, wherein the dosage of the catalyst was 0.1 g, the volume of the flue gas of domestic waste incineration was 5 m 3 , and the dioxin in the flue gas of domestic waste incineration The amount of dioxin is 1.0ng-TEQ/m 3 . According to the analysis results, it can be seen that the catalyst provided by the present invention can catalyze and degrade chlorobenzene, polychlorinated biphenyls, and dioxins in flue gas, and the degradation rates are 99.34%, 99.34%, and 98.59%, 98.77%.
  • the preparation method of the metal atom-supported carbon nanofiber catalyst provided by the present invention is simple in process, and the raw materials are cheap and easy to obtain.
  • metal atoms are supported in situ and the particle size of the product is controlled.
  • the preparation of raw materials can improve the dispersion and effectively inhibit the agglomeration of metals;
  • the prepared metal atom-supported carbon nanofiber catalyst contains a large number of carbon hollow nanobubbles, which improves the specific surface area of the catalyst and increases the active metal sites;
  • Metal exists in carbon nanofibers in the form of atoms, which has the advantages of high catalytic activity and low density.
  • the catalyst can be recycled and has certain industrial value. It can realize the catalysis of organic pollutants, especially UPOPs, at medium and low temperatures. Degradation, the degradation efficiency can reach more than 99.5%.

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Abstract

本发明提供提供一种金属原子负载型碳纳米纤维催化剂及其制备方法和应用，制备方法包括以下步骤：(1)使甲醇、金属盐和二甲基咪唑混合，得到第一混合体系；金属盐包括锌的可溶性盐，所述金属盐还包括铜的可溶性盐和/或镍的可溶性盐；使所述混合体系静置，产生沉淀；收集沉淀，将所述沉淀干燥后，制得负载有铜和/或镍的ZIF-8产物；(2)将ZIF-8产物加入含有含氮聚合物的溶液中，得到第二混合体系；将第二混合体系进行静电纺丝，制成纳米纤维产物；(3)将纳米纤维产物在不低于950℃下进行热解处理，得到金属原子负载型碳纳米纤维催化剂。该制备方法能够抑制金属团聚，制备得到的催化剂具有高分散性、低自由能等优点，能够用于催化降解有机污染物。

Description

金属原子负载型碳纳米纤维催化剂及其制备方法和应用 技术领域
本发明涉及催化剂制备技术领域，具体涉及一种金属原子负载型碳纳米纤维催化剂及其制备方法和应用。
背景技术
氯苯类有机污染物(CBzs)、多氯联苯(PCBs)、多氯代二苯并-对-二恶英(PCDD)、多氯代二苯并呋喃(PCDFs)和多氯化萘(PCNs)等无意产生类持久性有机污染物(UPOPs)主要产生于钢铁生产工艺中，例如通过铁矿石烧结生产钢铁的工艺中，该工艺不仅会产生粉尘、SO2、NOx等污染物，而且会产生UPOPs，对环境污染严重，不符合《炼铁工业大气污染物排放标准》和《炼钢工业大气污染物排放标准》等标准对UPOPs的排放要求(例如，一般要求二恶英类污染物的排放限值限定为0.5ng-TEQ/m3)。
目前，主要是通过焚烧结合活性炭吸附降解UPOPs，即先将含有UPOPs的污染物进行焚烧，再采用活性炭吸附该焚烧过程产生的尾气，一方面，该降解过程需要高温焚烧，能耗大，对设备要求苛刻，设备维护成本高，成本高，另一方面，通过活性炭吸附尾气，尾气中残留的UPOPs会吸附在活性炭中，吸附有UPOPs的活性炭处理难度大，且易导致二次污染，此外，目前的该处理过程对UPOPs的降解效率也有待进一步提高。
发明内容
本发明提供一种金属原子负载型碳纳米纤维催化剂及其制备方法和应用，该催化剂对UPOPs具有良好的催化降解性能，可避免现有降解UPOPs过程所存在的能耗大、成本高、易产生二次污染、降解效率低等缺陷。
本发明的一方面，提供一种金属原子负载型碳纳米纤维催化剂的制备方法，包括以下步骤：(1)使甲醇、第一金属盐、第二金属盐和二甲基咪唑混 合，得到第一混合体系；第一金属盐包括锌的可溶性盐，第二金属盐包括铜的可溶性盐和/或镍的可溶性盐；使混合体系静置，产生沉淀；收集沉淀，将沉淀干燥后，制得负载有铜和/或镍的ZIF-8产物；(2)将ZIF-8产物加入含有含氮聚合物的溶液中，得到第二混合体系；将第二混合体系进行静电纺丝，制成纳米纤维产物；(3)将纳米纤维产物在不低于950℃下进行热解处理，得到金属原子负载型碳纳米纤维催化剂。
根据本发明的一实施方式，在步骤(1)中，锌的可溶性盐与二甲基咪唑的摩尔比例为1～2.5：20。
根据本发明的一实施方式，干燥在真空条件下进行，干燥的温度为50～80℃。
根据本发明的一实施方式，铜的可溶性盐的用量满足：使ZIF-8产物中铜的质量含量为0～0.7％；和/或，镍的可溶性盐的用量满足：使ZIF-8产物中镍的质量含量为0～1.4％。
根据本发明的一实施方式，控制步骤(2)中所用的ZIF-8产物的粒径为60～100nm；和/或，含氮聚合物包括聚丙烯腈。
根据本发明的一实施方式，在步骤(2)中，ZIF-8产物与含氮聚合物的质量之比为0.1～2：1；和/或，含有含氮聚合物的溶液是将含氮聚合物溶于有机溶剂中制成，其中，有机溶剂与含氮聚合物的质量比为5:1～12:1。
根据本发明的一实施方式，静电纺丝处理的条件为：纺丝电压为20～25kV，纺丝口内径为0.6mm。
根据本发明的一实施方式，热解处理在惰性氛围下进行，和/或，热解处理的温度为950℃～1100℃，和/或，热解处理的时间为0.5～3h。
本发明的第二方面，提供一种金属原子负载型碳纳米纤维催化剂，由上述的金属原子负载型碳纳米纤维催化剂的制备方法制得。
本发明的第三方面，提供一种金属原子负载型碳纳米纤维催化剂在降解无意产生类持久性有机污染物中的应用。
本发明的实施，至少具有如下有益效果：
本发明中，通过上述制备过程，原位合成负载有铜和/或镍的ZIF-8产物，该ZIF-8产物具有比表面积高、孔道结构易修饰等特点，再将该ZIF-8产物与含氮聚合物混合液进行静电纺丝，制成纳米纤维产物，使纳米纤维产物在不 低于950℃下进行热解处理，制得金属原子负载型碳纳米纤维催化剂，研究显示，通过该制备方法制得的金属原子负载型碳纳米纤维催化剂中形成有大量纳米气泡，提高催化剂的比表面积，降低其密度，同时铜和/或镍以原子形式存在于该金属原子负载型碳纳米纤维催化剂中，且铜和/或镍原子在碳纳米纤维基体中具有良好的分散性，可以有效抑制铜和/或镍原子发生团聚，从而增加所制得的金属原子负载型碳纳米纤维催化剂的活性金属位点，使得金属原子负载型碳纳米纤维催化剂具有良好的催化活性、可循环再生等特性，对UPOPs表现出优异的降解效果(其对UPOPs的降解效率可达97.58％以上)，可避免现有降解UPOPs过程所存在的能耗大、成本高、易产生二次污染、降解效率低等缺陷，对于实际产业化应用具有重要意义。
附图说明
图1是本发明一实施方式中的金属原子负载型碳纳米纤维催化剂的扫描电镜图；
图2是本发明一实施方式中的金属原子负载型碳纳米纤维催化剂的高分辨透射电镜图。
具体实施方式
为使本领域技术人员更好地理解本发明的方案，下面对本发明作进一步地详细说明。
本发明的一方面，提供一种金属原子负载型碳纳米纤维催化剂的制备方法，包括以下步骤：(1)使甲醇、第一金属盐、第二金属盐和二甲基咪唑混合，得到第一混合体系；第一金属盐包括锌的可溶性盐，第二金属盐包括铜的可溶性盐和/或镍的可溶性盐；使混合体系静置，产生沉淀；收集沉淀，将沉淀干燥后，制得负载有铜和/或镍的ZIF-8产物；(2)将ZIF-8产物加入含有含氮聚合物的溶液中，得到第二混合体系；将第二混合体系进行静电纺丝，制成纳米纤维产物；(3)将纳米纤维产物在不低于950℃下进行热解处理，得到金属原子负载型碳纳米纤维催化剂。
具体地，在步骤(1)中，在第一混合体系中，锌的可溶性盐溶解在 甲醇中产生Zn 2+，Zn 2+与二甲基咪唑配位自组装成金属有机框架，即沸石咪唑酯骨架材料(ZIF-8)。其中ZIF-8的形成包括成核和晶体生长两个过程，首先，二甲基咪唑去质子化与Zn 2+配位形成晶核，然后晶核迅速增长形成ZIF-8纳米晶颗粒，即ZIF-8。一般情况下，加入过量的二甲基咪唑更利于ZIF-8晶体的快速生成。
上述负载有铜和/或镍的ZIF-8产物中，铜来自于铜的可溶性盐，镍来自于镍的可溶性盐，上述第二金属盐可以为铜的可溶性盐，或者为镍的可溶性盐，或者同时包括铜的可溶性盐与镍的可溶性盐。其中，铜的可溶性盐例如包括硝酸铜，镍的可溶性盐例如包括硝酸镍。此外，上述锌的可溶性盐可以包括硝酸锌。
在本发明的具体实施中，甲醇、第一金属盐、第二金属盐和二甲基咪唑的加入顺序不作限定。例如可以先将第一金属盐、第二金属盐、甲醇混合形成第一混合液，在二甲基咪唑中加入甲醇形成含有二甲基咪唑的甲醇溶液，然后将金属盐混合溶液和含有二甲基咪唑的甲醇溶液混合得到第一混合体系。
在本发明的具体实施中，甲醇优选为无水甲醇，甲醇作为分散介质，能够促进金属盐、二甲基咪唑的分散。
具体地，在步骤(1)中，收集沉淀的过程包括：将产生沉淀的第一混合体系进行离心处理，其中离心处理可以本领域常规手段进行，离心处理后将固体和液体分离，保留固体即收集得到的沉淀。一般情况下，离心处理在离心机中进行处理，在本发明的具体实施过程中，离心机在13000g条件下离心，离心处理时间为5min，例如可以是将第一混合体系置于离心机中在13000g的条件下运行5分钟，其中g是重力加速度。
一般情况下，收集沉淀后采用有机溶剂对沉淀进行洗涤处理，然后进行干燥得到负载有铜和/或镍的ZIF-8产物。其中洗涤处理可以采用本领域常规手段进行，其中有机溶剂包括甲醇。
在一些实施例中，第一混合体系中，锌的可溶性盐与二甲基咪唑的摩尔比例为1～2.5：20，例如1：20、1.5：20、2：20、2.5：20或其中的任意两者组成的范围，在本发明的具体实施中，原料加入顺序不做限定，只要将锌的可溶性盐、二甲基咪唑控制在上述摩尔比例即可。
在本发明的具体实施过程中，使甲醇、第一金属盐、第二金属盐和二甲基咪唑混合的过程包括：使第一金属盐、第二金属盐和部分甲醇混合，得到第一混合液；将二甲基咪唑溶于剩余甲醇中，得到第二混合液(即含有二甲基咪唑的甲醇溶液)；将第一混合液和第二混合液混合，得到第一混合体系。其中，第一混合液包括锌的可溶性盐和镍的可溶性盐，第一混合液中锌的可溶性盐的浓度为0.04～0.1mol/L，第一混合液中镍的可溶性盐的浓度为0.045～0.06mol/L，或者，第一混合液中包括锌的可溶性盐和铜的可溶性盐，该第一混合液中锌的可溶性盐的浓度为0.04～0.1mol/L，第一混合液中包括铜的可溶性盐的浓度为0.0025～0.0125mol/L。
具体实施时，使所述第一金属盐、第二金属盐和部分甲醇混合的过程可以包括：将第一金属盐的甲醇溶液、第二金属盐的甲醇溶液混合，得到第一混合液。
在一些实施例中，干燥在真空条件下进行，干燥的温度为50～80℃，例如50℃、60℃、70℃、80℃或其中的任意两者组成的范围。在干燥过程中，甲醇挥发，得到固体混合物，即负载有铜和/或镍的ZIF-8产物。根据加入的铜的可溶性盐、镍的可溶性盐的量，控制ZIF-8产物中铜和/或镍的负载的质量比例。负载铜和/或镍的ZIF-8产物，不会影响ZIF-8的孔道结构，镍、铜均匀分散在ZIF-8的表面及内部。
在一些实施例中，铜的可溶性盐的用量满足：使ZIF-8产物中铜的质量含量为0～0.7％，例如0、0.1％、0.2％、0.5％、0.7％或其中的任意两者组成的范围。
在一些实施例中，镍的可溶性盐的用量满足：使ZIF-8产物中镍的质量含量为0～1.4％，例如0、0.5％、1％、1.4％或其中的任意两者组成的范围。
在一些实施例中，控制步骤(2)中所用的ZIF-8产物的粒径为60～100nm，在负载镍或铜的基础上，控制ZIF-8产物的粒径，能够分散活性金属位点，抑制在后续热解处理中金属团聚，在本发明具体实施中，控制步骤(2)中所用的ZIF-8产物的粒径的具体过程包括：将步骤(1)得到的ZIF-8产物进行研磨，采用本领域技术人员熟知的研磨的技术方案即可，本发明对研磨的操作不作特殊的限定。在本发明的具体实施中，研磨 后得到的产物的粒径优选为60～100nm，例如60nm、80nm、100nm或其中的任意两者组成的范围。
一般情况下，含氮聚合物为含有氮的基团的聚合物，可以是含有氰基(-CN)、氨基(-NH 2)、亚氨基(-NH-)、酰胺基(-NH-CO-)等聚合物，例如聚丙烯腈、聚乙烯亚胺等，在一优选实施方式中，含氮聚合物包括聚丙烯腈。
在一些实施例中，第二混合体系中，ZIF-8产物与含氮聚合物的质量之比为0.1～2：1，例如0.1：1、0.5：1、1：1、1.5：1、2：1或其中的任意两者组成的范围。
在一些实施例中，将含氮聚合物溶于有机溶剂中，即得到含有含氮聚合物的溶液，其中有机溶剂与含氮聚合物的质量比为5:1～12:1，例如5:1、7:1、9:1、11:1、12:1或其中的任意两者组成的范围，在一优选实施方式中，有机溶剂包括N,N-二甲基甲酰胺，一般情况下为无色透明液体，将满足质量比的含氮聚合物加入N,N-二甲基甲酰胺中，混合均匀，例如可以在加热温度为60℃的条件下加热混合均匀。
在步骤(2)中，将含有含氮聚合物的溶液与ZIF-8产物均匀混合得到第二混合体系，采用本领域技术人员熟知的均匀混合的技术方案即可，例如可以在温度为60℃的条件下将含有含氮聚合物的溶液与ZIF-8产物均匀混合，即得到第二混合体系。
一般情况下，静电纺丝过程采用本领域常规的静电纺丝设备进行，将第二混合体系进行静电纺丝，得到纳米纤维状的纳米纤维产物，在一些实施例中，静电纺丝处理的条件为：纺丝电压为20～25kV，纺丝口内径为0.6mm。纺丝速度为0.6～0.8mL/h，所制备得到的纳米纤维产物的粒径为100～400nm，通过静电纺丝，进一步分散纳米纤维产物中ZIF-8的分布。
在步骤(3)中，将纳米纤维产物在不低于950℃下进行热解处理，得到金属原子负载型碳纳米纤维催化剂，在本发明的具体实施中，热解处理在惰性气氛或真空条件下进行，优选在惰性氛围下进行，例如氮气气氛。
在本发明的具体实施中，热解处理为恒温热解，热解处理的温度不低于950℃，优选为950～1100℃，例如950℃、980℃、1000℃、1100℃或其中的任意两者组成的范围；热解处理的时间为0.5～3h，例如0.5h、1h、 2h、3h或其中的任意两者组成的范围，热解处理的时间优选为2h，例如，热解处理可以在电加热反应釜中操作，将纳米纤维产物放入电加热反应釜中，以5℃/min的升温速率升温至1000℃，保温2h进行恒温热解处理。
在热解处理过程中，纳米纤维产物发生高温碳化过程，纳米纤维产物中的ZIF-8结构逐渐分解碳化形成碳纳米纤维，具有大量纳米空心气泡，即具有多孔结构，其中金属Zn逐渐挥发，并随着惰性气体排出，含有氮的基团分解形成氮掺杂到碳纳米纤维中，镍盐、铜盐分解为镍原子、铜原子负载在碳纳米纤维上，形成镍和/或铜-碳-氮的结构。
步骤(3)的热解处理完成后，在本发明的具体实施中，优选将热解处理的产物冷却后进行研磨，得到金属原子负载型碳纳米纤维催化剂。本发明对冷却和研磨的操作没有特殊的限定，采用本领域技术人员熟知的冷却和研磨的技术方案即可。在本发明中，金属原子负载型碳纳米纤维催化剂的粒径优选为200～300nm。
本发明的第二方面，提供一种金属原子负载型碳纳米纤维催化剂，由上述的金属原子负载型碳纳米纤维催化剂的制备方法制得。该金属原子负载型碳纳米纤维催化剂含有大量纳米空心气泡，具有比表面积大、密度低、分散性好等优点，具体的比表面积可达500～700平方米/克，由于该金属原子负载型碳纳米纤维催化剂具有多孔碳纳米纤维结构，能够提高对气体的吸附能力，此外该金属原子负载型碳纳米纤维催化剂中含有过渡金属，不仅增加了活性金属位点，而且具有高分散性，大幅提高了该催化剂的反应活性。
本发明的第三方面，提供一种金属原子负载型碳纳米纤维催化剂在降解无意产生类持久性有机污染物(UPOPs)中的应用。
本发明提供的催化剂可用于含有UPOPs的烟气的净化处理，不仅对高UPOPs浓度的烟气具有优异的净化效果，对低UPOPs浓度(0.1ng-TEQ/m 3)的烟气也能够达到良好的净化效果。该烟气可以包括生活垃圾焚烧烟气、再生铜冶炼烟气、铁矿石烧结烟气等中的至少一种。
具体地，UPOPs包括多氯联苯、氯苯、二恶英中的至少一种，本发明的金属原子负载型碳纳米纤维催化剂对多氯联苯、氯苯、二恶英均具有良好的降解效果，降解效率可高达97.58％以上。
在本发明的具体实施过程中，将含有UPOPs的烟气与催化剂接触进行净化处理后，得到净化后的烟气，采用气相色谱-质谱联用仪(GC-MS)对氯苯进行定量分析，采用高分辨气相色谱-高分辨质谱联用(HRGC-HRMS)对二噁英、多氯联苯进行定量分析。分别测量含有UPOPs的烟气和净化后的烟气中多氯联苯、氯苯、二恶英的量，计算得到相对应的降解率。
采用本发明的金属原子负载型碳纳米纤维催化剂，降解过程条件温和，在一些实施例中，催化降解的温度为150～350℃，例如150℃、200℃、250℃、300℃、350℃或其中的任意两者组成的范围，在本发明的具体实施过程中，上述降解过程在惰性气氛下进行，该惰性气氛例如包括氮气气氛。
在本发明的具体实施实施中，将0.1g的催化剂填充于管式反应器中形成一段催化层，在管式反应器中通入含有UPOPs的烟气，含有UPOPs的烟气经过催化层时进行净化处理，其中管式反应器的直径为1cm，催化层的高度为2cm，在本发明的具体实施中，单克催化剂可以降解100微克的二恶英类污染物，其中g为克。
下面通过具体实施例和对比例对本发明作进一步的说明。如无特别说明，下述所使用到的试剂、材料以及仪器均为常规试剂、常规材料以及常规仪器，均可商购获得，所涉及的试剂、材料也可通过常规合成方法合成获得，如无特别说明，本发明的g均为重量单位。
实施例1
(1)将硝酸锌、硝酸镍、硝酸铜、甲醇混合均匀，形成100mL的第一混合液；该第一混合液中，硝酸锌的浓度为4mmoL，硝酸镍的浓度为6mmoL，硝酸铜的浓度为0.5mmoL；
称取6.568g的二甲基咪唑加入80mL甲醇中形成第二混合液，再将第一混合液与第二混合液混合均匀，形成第一混合体系；
使第一混合体系静置，产生沉淀，进行离心处理，采用甲醇清洗沉淀后，进行干燥得到负载有铜和镍的ZIF-8产物(Ni-Cu-ZIF-8)；其中离心处理在离心机中进行处理，离心机在13000g(其中g为重力加速度)条件下离心，离心处理时间为5min，干燥条件为在真空条件下进行，干燥温度 为60℃；
(2)在4.5g的N,N-二甲基甲酰胺中加入0.5g的聚丙烯腈，在60℃条件下加热、混合均匀得到含有聚丙烯腈的溶液；
(3)称取0.5g的ZIF-8产物，加入含有聚丙烯腈的溶液中，在60℃条件下加热、混合均匀得到第二混合体系；
(4)将第二混合体系进行静电纺丝得到纳米纤维产物，其中静电纺丝的条件为：纺丝电压为20kV，纺丝口内径为0.6mm；
(5)将纳米纤维产物进行热解处理，得到金属原子负载型碳纳米纤维催化剂，其中热解处理的条件为：在氮气气氛下进行，以5℃/min的升温速率升温至1000℃，恒温2h。
根据电感耦合等离子体发射光谱仪(ICP-OES)分析结果可知，实施例1中负载有铜和镍的ZIF-8产物中，Ni和Cu的质量含量(负载比例)均为0.7wt％。
将实施例1中的催化剂，在350℃的条件下对铁矿石烧结烟气进行处理，其中催化剂的质量为0.1g，铁矿石烧结烟气体积为2m 3，铁矿石烧结烟气中二恶英的量为1.2ng-TEQ/m 3，根据分析结果可知，采用本发明提供的催化剂，可以催化降解烟气中的氯苯、多氯联苯、二恶英类有机污染物，降解率分别为99.95％、99.73％、99.92％。
实施例2
与实施例1相比，步骤(1)中不加入硝酸铜，在步骤(3)中，将0.5g的ZIF-8产物替换为0.8g的ZIF-8产物，在步骤(4)中，将纺丝电压为20kV替换为纺丝压力为21kV，其他条件不变。
根据电感耦合等离子体发射光谱仪(ICP-OES)分析结果可知，实施例2中负载有镍的ZIF-8产物中，Ni的质量含量(负载比例)为0.7wt％。
将实施例2中的催化剂，在300℃的条件下对再生铜冶炼烟气进行处理，其中催化剂的质量为0.1g，再生铜冶炼烟气的体积为1m 3，再生铜冶炼烟气中二恶英的量为0.5ng-TEQ/m 3，根据分析结果可知，采用本发明提供的催化剂，可以催化降解烟气中的氯苯、多氯联苯、二恶英类有机污染物，降解率分别为99.02％、97.58％、98.76％。
实施例3
与实施例1相比，步骤(1)中不加入硝酸镍，并将硝酸锌的浓度为4mmoL，硝酸铜的浓度为0.5mmoL替换为硝酸锌的浓度为10mmoL，硝酸铜的浓度为1.25mmoL，在步骤(2)中，将在4.5g的N,N-二甲基甲酰胺中加入0.5g的聚丙烯腈替换为在5.4g的N,N-二甲基甲酰胺中加入0.6g的聚丙烯腈，在步骤(3)中，将0.5g的ZIF-8产物替换为1.2g的ZIF-8产物，其他条件不变。
根据电感耦合等离子体发射光谱仪(ICP-OES)分析结果可知，实施例3中负载有铜的ZIF-8产物中，Cu的质量含量(负载比例)为1.4wt％。
将实施例3中的催化剂，在300℃的条件下对生活垃圾焚烧烟气进行处理，其中催化剂的用量为0.1g，生活垃圾焚烧烟气的体积为5m 3，生活垃圾焚烧烟气中二恶英的量为1.0ng-TEQ/m 3，根据分析结果可知，采用本发明提供的催化剂，可以催化降解烟气中的氯苯、多氯联苯、二恶英，降解率分别为99.34％、98.59％、98.77％。
综上，本发明提供的的金属原子负载型碳纳米纤维催化剂的制备方法工艺简单、原料廉价易得，在制备过程中通过原位负载金属原子并控制产物粒径大小，同时使用静电纺丝分散制备原料，能够提高分散性，有效抑制了金属的团聚；制备得到的金属原子负载型碳纳米纤维催化剂含有大量碳空心纳米气泡，提高了该催化剂的比表面积，增加活性金属位点；该催化剂中金属以原子的形式存在于碳纳米纤维中，具有催化活性高、密度低等优点，此外该催化剂可循环再生，具有一定的工业价值，能够实现在中低温对有机污染物，尤其是UPOPs的催化降解，降解效率可达99.5％以上。
以上，对本发明的实施方式进行了说明。但是，本发明不限定于上述实施方式。凡在本发明的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。

Claims (10)

  1. 一种金属原子负载型碳纳米纤维催化剂的制备方法，其特征在于，包括以下步骤：
    (1)使甲醇、第一金属盐、第二金属盐和二甲基咪唑混合，得到第一混合体系；所述第一金属盐包括锌的可溶性盐，所述第二金属盐包括铜的可溶性盐和/或镍的可溶性盐；
    使所述混合体系静置，产生沉淀；
    收集所述沉淀，将所述沉淀干燥后，制得负载有铜和/或镍的ZIF-8产物；
    (2)将所述ZIF-8产物加入含有含氮聚合物的溶液中，得到第二混合体系；将所述第二混合体系进行静电纺丝，制成纳米纤维产物；
    (3)将所述纳米纤维产物在不低于950℃下进行热解处理，得到金属原子负载型碳纳米纤维催化剂。
  2. 根据权利要求1所述的金属原子负载型碳纳米纤维催化剂的制备方法，其特征在于，在步骤(1)中，所述锌的可溶性盐与二甲基咪唑的摩尔比例为1～2.5：20。
  3. 根据权利要求1所述的金属原子负载型碳纳米纤维催化剂的制备方法，其特征在于，所述干燥在真空条件下进行，所述干燥的温度为50～80℃。
  4. 根据权利要求1所述的金属原子负载型碳纳米纤维催化剂的制备方法，其特征在于，所述铜的可溶性盐的用量满足：使ZIF-8产物中铜的质量含量为0～0.7％；和/或，所述镍的可溶性盐的用量满足：使ZIF-8产物中镍的质量含量为0～1.4％。
  5. 根据权利要求1所述的金属原子负载型碳纳米纤维催化剂的制备方法，其特征在于，控制步骤(2)中所用的ZIF-8产物的粒径为60～100nm；和/或，所述含氮聚合物包括聚丙烯腈。
  6. 根据权利要求1或5所述的金属原子负载型碳纳米纤维催化剂的制备方法，其特征在于，在步骤(2)中，所述ZIF-8产物与含氮聚合物的质量之比为0.1～2：1；和/或，
    所述含有含氮聚合物的溶液是将含氮聚合物溶于有机溶剂中制成，其中，所述有机溶剂与所述含氮聚合物的质量比为5:1～12:1。
  7. 根据权利要求1所述的金属原子负载型碳纳米纤维催化剂的制备方法，其特征在于，所述静电纺丝处理的条件为：纺丝电压为20～25kV，纺丝口内径为0.6mm。
  8. 根据权利要求1所述的金属原子负载型碳纳米纤维催化剂的制备方法，其特征在于，所述热解处理在惰性氛围下进行，和/或，所述热解处理的温度为950℃～1100℃，和/或，所述热解处理的时间为0.5～3h。
  9. 一种金属原子负载型碳纳米纤维催化剂，其特征在于，由权利要求1-8任一项所述的金属原子负载型碳纳米纤维催化剂的制备方法制得。
  10. 权利要求9所述的金属原子负载型碳纳米纤维催化剂在降解无意产生类持久性有机污染物中的应用。
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105862174A (zh) * 2016-04-08 2016-08-17 合肥工业大学 一种新型金属有机配合物纤维及其衍生多孔碳纤维的制备方法
CN107020101A (zh) * 2017-03-24 2017-08-08 兰州大学 一种含氧化锌的纳米碳纤维负载镍基催化材料及其制备方法
CN111068734A (zh) * 2019-12-24 2020-04-28 新疆大学 一种用于高效双功能电催化的竹节状氮掺杂碳纳米纤维包覆过渡金属合金纳米粒子催化材料
CN111081995A (zh) * 2019-11-07 2020-04-28 东北大学 一种基于MOFs衍生金属氧化物碳纳米纤维电极材料的制备方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105862174A (zh) * 2016-04-08 2016-08-17 合肥工业大学 一种新型金属有机配合物纤维及其衍生多孔碳纤维的制备方法
CN107020101A (zh) * 2017-03-24 2017-08-08 兰州大学 一种含氧化锌的纳米碳纤维负载镍基催化材料及其制备方法
CN111081995A (zh) * 2019-11-07 2020-04-28 东北大学 一种基于MOFs衍生金属氧化物碳纳米纤维电极材料的制备方法
CN111068734A (zh) * 2019-12-24 2020-04-28 新疆大学 一种用于高效双功能电催化的竹节状氮掺杂碳纳米纤维包覆过渡金属合金纳米粒子催化材料

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
SUN YIFEI, LIU LINA, OSHITA KAZUYUKI, ZENG XIAOLAN, WANG WEI, ZHANG YIBO: "Influence of activated-carbon-supported transition metals on the decomposition of polychlorobiphenyls. Part II: Chemical and physical characterization and mechanistic study", CHEMOSPHERE, PERGAMON PRESS, OXFORD., GB, vol. 159, 1 September 2016 (2016-09-01), GB , pages 668 - 675, XP093038907, ISSN: 0045-6535, DOI: 10.1016/j.chemosphere.2016.05.091 *
WANG JIANHONG; CAI CHAO; ZHANG ZHIJIE; LI CONGLING; LIU RUI: "Electrospun metal-organic frameworks with polyacrylonitrile as precursors to hierarchical porous carbon and composite nanofibers for adsorption and catalysis", CHEMOSPHERE, PERGAMON PRESS, OXFORD., GB, vol. 239, 10 September 2019 (2019-09-10), GB , XP085892483, ISSN: 0045-6535, DOI: 10.1016/j.chemosphere.2019.124833 *

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